refactor(session): effectify session processor (#19485)

packages/opencode/src/effect/run-service.ts

@@ -9,6 +9,8 @@ export function makeRuntime<I, S, E>(service: ServiceMap.Service<I, S>, layer: L
 
   return {
     runSync: <A, Err>(fn: (svc: S) => Effect.Effect<A, Err, I>) => getRuntime().runSync(service.use(fn)),
+    runPromiseExit: <A, Err>(fn: (svc: S) => Effect.Effect<A, Err, I>, options?: Effect.RunOptions) =>
+      getRuntime().runPromiseExit(service.use(fn), options),
     runPromise: <A, Err>(fn: (svc: S) => Effect.Effect<A, Err, I>, options?: Effect.RunOptions) =>
       getRuntime().runPromise(service.use(fn), options),
     runFork: <A, Err>(fn: (svc: S) => Effect.Effect<A, Err, I>) => getRuntime().runFork(service.use(fn)),

packages/opencode/src/session/compaction.ts

@@ -14,10 +14,10 @@ import { Agent } from "@/agent/agent"
 import { Plugin } from "@/plugin"
 import { Config } from "@/config/config"
 import { NotFoundError } from "@/storage/db"
-import { ProviderTransform } from "@/provider/transform"
 import { ModelID, ProviderID } from "@/provider/schema"
-import { Effect, Layer, ServiceMap } from "effect"
+import { Cause, Effect, Exit, Layer, ServiceMap } from "effect"
 import { makeRuntime } from "@/effect/run-service"
+import { isOverflow as overflow } from "./overflow"
 
 export namespace SessionCompaction {
   const log = Log.create({ service: "session.compaction" })
@@ -31,7 +31,6 @@ export namespace SessionCompaction {
     ),
   }
 
-  const COMPACTION_BUFFER = 20_000
   export const PRUNE_MINIMUM = 20_000
   export const PRUNE_PROTECT = 40_000
   const PRUNE_PROTECTED_TOOLS = ["skill"]
@@ -64,7 +63,7 @@ export namespace SessionCompaction {
   export const layer: Layer.Layer<
     Service,
     never,
-    Bus.Service | Config.Service | Session.Service | Agent.Service | Plugin.Service
+    Bus.Service | Config.Service | Session.Service | Agent.Service | Plugin.Service | SessionProcessor.Service
   > = Layer.effect(
     Service,
     Effect.gen(function* () {
@@ -73,26 +72,13 @@ export namespace SessionCompaction {
       const session = yield* Session.Service
       const agents = yield* Agent.Service
       const plugin = yield* Plugin.Service
+      const processors = yield* SessionProcessor.Service
 
       const isOverflow = Effect.fn("SessionCompaction.isOverflow")(function* (input: {
         tokens: MessageV2.Assistant["tokens"]
         model: Provider.Model
       }) {
-        const cfg = yield* config.get()
-        if (cfg.compaction?.auto === false) return false
-        const context = input.model.limit.context
-        if (context === 0) return false
-
-        const count =
-          input.tokens.total ||
-          input.tokens.input + input.tokens.output + input.tokens.cache.read + input.tokens.cache.write
-
-        const reserved =
-          cfg.compaction?.reserved ?? Math.min(COMPACTION_BUFFER, ProviderTransform.maxOutputTokens(input.model))
-        const usable = input.model.limit.input
-          ? input.model.limit.input - reserved
-          : context - ProviderTransform.maxOutputTokens(input.model)
-        return count >= usable
+        return overflow({ cfg: yield* config.get(), tokens: input.tokens, model: input.model })
       })
 
       // goes backwards through parts until there are PRUNE_PROTECT tokens worth of tool
@@ -181,38 +167,6 @@ export namespace SessionCompaction {
             ? Provider.getModel(agent.model.providerID, agent.model.modelID)
             : Provider.getModel(userMessage.model.providerID, userMessage.model.modelID),
         )
-        const msg = (yield* session.updateMessage({
-          id: MessageID.ascending(),
-          role: "assistant",
-          parentID: input.parentID,
-          sessionID: input.sessionID,
-          mode: "compaction",
-          agent: "compaction",
-          variant: userMessage.variant,
-          summary: true,
-          path: {
-            cwd: Instance.directory,
-            root: Instance.worktree,
-          },
-          cost: 0,
-          tokens: {
-            output: 0,
-            input: 0,
-            reasoning: 0,
-            cache: { read: 0, write: 0 },
-          },
-          modelID: model.id,
-          providerID: model.providerID,
-          time: {
-            created: Date.now(),
-          },
-        })) as MessageV2.Assistant
-        const processor = SessionProcessor.create({
-          assistantMessage: msg,
-          sessionID: input.sessionID,
-          model,
-          abort: input.abort,
-        })
         // Allow plugins to inject context or replace compaction prompt.
         const compacting = yield* plugin.trigger(
           "experimental.session.compacting",
@@ -251,8 +205,47 @@ When constructing the summary, try to stick to this template:
         const msgs = structuredClone(messages)
         yield* plugin.trigger("experimental.chat.messages.transform", {}, { messages: msgs })
         const modelMessages = yield* Effect.promise(() => MessageV2.toModelMessages(msgs, model, { stripMedia: true }))
-        const result = yield* Effect.promise(() =>
-          processor.process({
+        const msg = (yield* session.updateMessage({
+          id: MessageID.ascending(),
+          role: "assistant",
+          parentID: input.parentID,
+          sessionID: input.sessionID,
+          mode: "compaction",
+          agent: "compaction",
+          variant: userMessage.variant,
+          summary: true,
+          path: {
+            cwd: Instance.directory,
+            root: Instance.worktree,
+          },
+          cost: 0,
+          tokens: {
+            output: 0,
+            input: 0,
+            reasoning: 0,
+            cache: { read: 0, write: 0 },
+          },
+          modelID: model.id,
+          providerID: model.providerID,
+          time: {
+            created: Date.now(),
+          },
+        })) as MessageV2.Assistant
+        const processor = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: input.sessionID,
+          model,
+          abort: input.abort,
+        })
+        const cancel = Effect.fn("SessionCompaction.cancel")(function* () {
+          if (!input.abort.aborted || msg.time.completed) return
+          msg.error = msg.error ?? new MessageV2.AbortedError({ message: "Aborted" }).toObject()
+          msg.finish = msg.finish ?? "error"
+          msg.time.completed = Date.now()
+          yield* session.updateMessage(msg)
+        })
+        const result = yield* processor
+          .process({
             user: userMessage,
             agent,
             abort: input.abort,
@@ -267,8 +260,8 @@ When constructing the summary, try to stick to this template:
               },
             ],
             model,
-          }),
-        )
+          })
+          .pipe(Effect.ensuring(cancel()))
 
         if (result === "compact") {
           processor.message.error = new MessageV2.ContextOverflowError({
@@ -383,6 +376,7 @@ When constructing the summary, try to stick to this template:
     Effect.sync(() =>
       layer.pipe(
         Layer.provide(Session.defaultLayer),
+        Layer.provide(SessionProcessor.defaultLayer),
         Layer.provide(Agent.defaultLayer),
         Layer.provide(Plugin.defaultLayer),
         Layer.provide(Bus.layer),
@@ -391,7 +385,7 @@ When constructing the summary, try to stick to this template:
     ),
   )
 
-  const { runPromise } = makeRuntime(Service, defaultLayer)
+  const { runPromise, runPromiseExit } = makeRuntime(Service, defaultLayer)
 
   export async function isOverflow(input: { tokens: MessageV2.Assistant["tokens"]; model: Provider.Model }) {
     return runPromise((svc) => svc.isOverflow(input))
@@ -409,7 +403,12 @@ When constructing the summary, try to stick to this template:
     auto: boolean
     overflow?: boolean
   }) {
-    return runPromise((svc) => svc.process(input))
+    const exit = await runPromiseExit((svc) => svc.process(input), { signal: input.abort })
+    if (Exit.isFailure(exit)) {
+      if (Cause.hasInterrupts(exit.cause) && input.abort.aborted) return "stop"
+      throw Cause.squash(exit.cause)
+    }
+    return exit.value
   }
 
   export const create = fn(

packages/opencode/src/session/llm.ts

@@ -1,5 +1,7 @@
 import { Provider } from "@/provider/provider"
 import { Log } from "@/util/log"
+import { Effect, Layer, ServiceMap } from "effect"
+import * as Stream from "effect/Stream"
 import { streamText, wrapLanguageModel, type ModelMessage, type Tool, tool, jsonSchema } from "ai"
 import { mergeDeep, pipe } from "remeda"
 import { GitLabWorkflowLanguageModel } from "gitlab-ai-provider"
@@ -34,6 +36,35 @@ export namespace LLM {
     toolChoice?: "auto" | "required" | "none"
   }
 
+  export type Event = Awaited<ReturnType<typeof stream>>["fullStream"] extends AsyncIterable<infer T> ? T : never
+
+  export interface Interface {
+    readonly stream: (input: StreamInput) => Stream.Stream<Event, unknown>
+  }
+
+  export class Service extends ServiceMap.Service<Service, Interface>()("@opencode/LLM") {}
+
+  export const layer = Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      return Service.of({
+        stream(input) {
+          return Stream.unwrap(
+            Effect.promise(() => LLM.stream(input)).pipe(
+              Effect.map((result) =>
+                Stream.fromAsyncIterable(result.fullStream, (err) => err).pipe(
+                  Stream.mapEffect((event) => Effect.succeed(event)),
+                ),
+              ),
+            ),
+          )
+        },
+      })
+    }),
+  )
+
+  export const defaultLayer = layer
+
   export async function stream(input: StreamInput) {
     const l = log
       .clone()

packages/opencode/src/session/overflow.ts

@@ -0,0 +1,22 @@
+import type { Config } from "@/config/config"
+import type { Provider } from "@/provider/provider"
+import { ProviderTransform } from "@/provider/transform"
+import type { MessageV2 } from "./message-v2"
+
+const COMPACTION_BUFFER = 20_000
+
+export function isOverflow(input: { cfg: Config.Info; tokens: MessageV2.Assistant["tokens"]; model: Provider.Model }) {
+  if (input.cfg.compaction?.auto === false) return false
+  const context = input.model.limit.context
+  if (context === 0) return false
+
+  const count =
+    input.tokens.total || input.tokens.input + input.tokens.output + input.tokens.cache.read + input.tokens.cache.write
+
+  const reserved =
+    input.cfg.compaction?.reserved ?? Math.min(COMPACTION_BUFFER, ProviderTransform.maxOutputTokens(input.model))
+  const usable = input.model.limit.input
+    ? input.model.limit.input - reserved
+    : context - ProviderTransform.maxOutputTokens(input.model)
+  return count >= usable
+}

packages/opencode/src/session/processor.ts

@@ -1,430 +1,554 @@
-import { MessageV2 } from "./message-v2"
-import { Log } from "@/util/log"
-import { Session } from "."
+import { Cause, Effect, Exit, Layer, ServiceMap } from "effect"
+import * as Stream from "effect/Stream"
 import { Agent } from "@/agent/agent"
-import { Snapshot } from "@/snapshot"
-import { SessionSummary } from "./summary"
 import { Bus } from "@/bus"
+import { makeRuntime } from "@/effect/run-service"
+import { Config } from "@/config/config"
+import { Permission } from "@/permission"
+import { Plugin } from "@/plugin"
+import { Snapshot } from "@/snapshot"
+import { Log } from "@/util/log"
+import { Session } from "."
+import { LLM } from "./llm"
+import { MessageV2 } from "./message-v2"
+import { isOverflow } from "./overflow"
+import { PartID } from "./schema"
+import type { SessionID } from "./schema"
 import { SessionRetry } from "./retry"
 import { SessionStatus } from "./status"
-import { Plugin } from "@/plugin"
+import { SessionSummary } from "./summary"
 import type { Provider } from "@/provider/provider"
-import { LLM } from "./llm"
-import { Config } from "@/config/config"
-import { SessionCompaction } from "./compaction"
-import { Permission } from "@/permission"
 import { Question } from "@/question"
-import { PartID } from "./schema"
-import type { SessionID, MessageID } from "./schema"
 
 export namespace SessionProcessor {
   const DOOM_LOOP_THRESHOLD = 3
   const log = Log.create({ service: "session.processor" })
 
-  export type Info = Awaited<ReturnType<typeof create>>
-  export type Result = Awaited<ReturnType<Info["process"]>>
+  export type Result = "compact" | "stop" | "continue"
+
+  export type Event = LLM.Event
+
+  export interface Handle {
+    readonly message: MessageV2.Assistant
+    readonly partFromToolCall: (toolCallID: string) => MessageV2.ToolPart | undefined
+    readonly abort: () => Effect.Effect<void>
+    readonly process: (streamInput: LLM.StreamInput) => Effect.Effect<Result>
+  }
+
+  export interface Info {
+    readonly message: MessageV2.Assistant
+    readonly partFromToolCall: (toolCallID: string) => MessageV2.ToolPart | undefined
+    readonly process: (streamInput: LLM.StreamInput) => Promise<Result>
+  }
 
-  export function create(input: {
+  type Input = {
     assistantMessage: MessageV2.Assistant
     sessionID: SessionID
     model: Provider.Model
     abort: AbortSignal
-  }) {
-    const toolcalls: Record<string, MessageV2.ToolPart> = {}
-    let snapshot: string | undefined
-    let blocked = false
-    let attempt = 0
-    let needsCompaction = false
-
-    const result = {
-      get message() {
-        return input.assistantMessage
-      },
-      partFromToolCall(toolCallID: string) {
-        return toolcalls[toolCallID]
-      },
-      async process(streamInput: LLM.StreamInput) {
-        log.info("process")
-        needsCompaction = false
-        const shouldBreak = (await Config.get()).experimental?.continue_loop_on_deny !== true
-        while (true) {
-          try {
-            let currentText: MessageV2.TextPart | undefined
-            let reasoningMap: Record<string, MessageV2.ReasoningPart> = {}
-            const stream = await LLM.stream(streamInput)
-
-            for await (const value of stream.fullStream) {
-              input.abort.throwIfAborted()
-              switch (value.type) {
-                case "start":
-                  await SessionStatus.set(input.sessionID, { type: "busy" })
-                  break
-
-                case "reasoning-start":
-                  if (value.id in reasoningMap) {
-                    continue
-                  }
-                  const reasoningPart = {
-                    id: PartID.ascending(),
-                    messageID: input.assistantMessage.id,
-                    sessionID: input.assistantMessage.sessionID,
-                    type: "reasoning" as const,
-                    text: "",
-                    time: {
-                      start: Date.now(),
-                    },
-                    metadata: value.providerMetadata,
-                  }
-                  reasoningMap[value.id] = reasoningPart
-                  await Session.updatePart(reasoningPart)
-                  break
-
-                case "reasoning-delta":
-                  if (value.id in reasoningMap) {
-                    const part = reasoningMap[value.id]
-                    part.text += value.text
-                    if (value.providerMetadata) part.metadata = value.providerMetadata
-                    await Session.updatePartDelta({
-                      sessionID: part.sessionID,
-                      messageID: part.messageID,
-                      partID: part.id,
-                      field: "text",
-                      delta: value.text,
-                    })
-                  }
-                  break
-
-                case "reasoning-end":
-                  if (value.id in reasoningMap) {
-                    const part = reasoningMap[value.id]
-                    part.text = part.text.trimEnd()
-
-                    part.time = {
-                      ...part.time,
-                      end: Date.now(),
-                    }
-                    if (value.providerMetadata) part.metadata = value.providerMetadata
-                    await Session.updatePart(part)
-                    delete reasoningMap[value.id]
-                  }
-                  break
-
-                case "tool-input-start":
-                  const part = await Session.updatePart({
-                    id: toolcalls[value.id]?.id ?? PartID.ascending(),
-                    messageID: input.assistantMessage.id,
-                    sessionID: input.assistantMessage.sessionID,
-                    type: "tool",
-                    tool: value.toolName,
-                    callID: value.id,
-                    state: {
-                      status: "pending",
-                      input: {},
-                      raw: "",
-                    },
-                  })
-                  toolcalls[value.id] = part as MessageV2.ToolPart
-                  break
-
-                case "tool-input-delta":
-                  break
-
-                case "tool-input-end":
-                  break
-
-                case "tool-call": {
-                  const match = toolcalls[value.toolCallId]
-                  if (match) {
-                    const part = await Session.updatePart({
-                      ...match,
-                      tool: value.toolName,
-                      state: {
-                        status: "running",
-                        input: value.input,
-                        time: {
-                          start: Date.now(),
-                        },
-                      },
-                      metadata: value.providerMetadata,
-                    })
-                    toolcalls[value.toolCallId] = part as MessageV2.ToolPart
-
-                    const parts = await MessageV2.parts(input.assistantMessage.id)
-                    const lastThree = parts.slice(-DOOM_LOOP_THRESHOLD)
-
-                    if (
-                      lastThree.length === DOOM_LOOP_THRESHOLD &&
-                      lastThree.every(
-                        (p) =>
-                          p.type === "tool" &&
-                          p.tool === value.toolName &&
-                          p.state.status !== "pending" &&
-                          JSON.stringify(p.state.input) === JSON.stringify(value.input),
-                      )
-                    ) {
-                      const agent = await Agent.get(input.assistantMessage.agent)
-                      await Permission.ask({
-                        permission: "doom_loop",
-                        patterns: [value.toolName],
-                        sessionID: input.assistantMessage.sessionID,
-                        metadata: {
-                          tool: value.toolName,
-                          input: value.input,
-                        },
-                        always: [value.toolName],
-                        ruleset: agent.permission,
-                      })
-                    }
-                  }
-                  break
-                }
-                case "tool-result": {
-                  const match = toolcalls[value.toolCallId]
-                  if (match && match.state.status === "running") {
-                    await Session.updatePart({
-                      ...match,
-                      state: {
-                        status: "completed",
-                        input: value.input ?? match.state.input,
-                        output: value.output.output,
-                        metadata: value.output.metadata,
-                        title: value.output.title,
-                        time: {
-                          start: match.state.time.start,
-                          end: Date.now(),
-                        },
-                        attachments: value.output.attachments,
-                      },
-                    })
-
-                    delete toolcalls[value.toolCallId]
-                  }
-                  break
-                }
+  }
 
-                case "tool-error": {
-                  const match = toolcalls[value.toolCallId]
-                  if (match && match.state.status === "running") {
-                    await Session.updatePart({
-                      ...match,
-                      state: {
-                        status: "error",
-                        input: value.input ?? match.state.input,
-                        error: value.error instanceof Error ? value.error.message : String(value.error),
-                        time: {
-                          start: match.state.time.start,
-                          end: Date.now(),
-                        },
-                      },
-                    })
-
-                    if (
-                      value.error instanceof Permission.RejectedError ||
-                      value.error instanceof Question.RejectedError
-                    ) {
-                      blocked = shouldBreak
-                    }
-                    delete toolcalls[value.toolCallId]
-                  }
-                  break
-                }
-                case "error":
-                  throw value.error
+  export interface Interface {
+    readonly create: (input: Input) => Effect.Effect<Handle>
+  }
 
-                case "start-step":
-                  snapshot = await Snapshot.track()
-                  await Session.updatePart({
-                    id: PartID.ascending(),
-                    messageID: input.assistantMessage.id,
-                    sessionID: input.sessionID,
-                    snapshot,
-                    type: "step-start",
-                  })
-                  break
+  interface ProcessorContext extends Input {
+    toolcalls: Record<string, MessageV2.ToolPart>
+    shouldBreak: boolean
+    snapshot: string | undefined
+    blocked: boolean
+    needsCompaction: boolean
+    currentText: MessageV2.TextPart | undefined
+    reasoningMap: Record<string, MessageV2.ReasoningPart>
+  }
 
-                case "finish-step":
-                  const usage = Session.getUsage({
-                    model: input.model,
-                    usage: value.usage,
-                    metadata: value.providerMetadata,
-                  })
-                  input.assistantMessage.finish = value.finishReason
-                  input.assistantMessage.cost += usage.cost
-                  input.assistantMessage.tokens = usage.tokens
-                  await Session.updatePart({
-                    id: PartID.ascending(),
-                    reason: value.finishReason,
-                    snapshot: await Snapshot.track(),
-                    messageID: input.assistantMessage.id,
-                    sessionID: input.assistantMessage.sessionID,
-                    type: "step-finish",
-                    tokens: usage.tokens,
-                    cost: usage.cost,
-                  })
-                  await Session.updateMessage(input.assistantMessage)
-                  if (snapshot) {
-                    const patch = await Snapshot.patch(snapshot)
-                    if (patch.files.length) {
-                      await Session.updatePart({
-                        id: PartID.ascending(),
-                        messageID: input.assistantMessage.id,
-                        sessionID: input.sessionID,
-                        type: "patch",
-                        hash: patch.hash,
-                        files: patch.files,
-                      })
-                    }
-                    snapshot = undefined
-                  }
-                  SessionSummary.summarize({
-                    sessionID: input.sessionID,
-                    messageID: input.assistantMessage.parentID,
-                  })
-                  if (
-                    !input.assistantMessage.summary &&
-                    (await SessionCompaction.isOverflow({ tokens: usage.tokens, model: input.model }))
-                  ) {
-                    needsCompaction = true
-                  }
-                  break
-
-                case "text-start":
-                  currentText = {
-                    id: PartID.ascending(),
-                    messageID: input.assistantMessage.id,
-                    sessionID: input.assistantMessage.sessionID,
-                    type: "text",
-                    text: "",
-                    time: {
-                      start: Date.now(),
-                    },
-                    metadata: value.providerMetadata,
-                  }
-                  await Session.updatePart(currentText)
-                  break
-
-                case "text-delta":
-                  if (currentText) {
-                    currentText.text += value.text
-                    if (value.providerMetadata) currentText.metadata = value.providerMetadata
-                    await Session.updatePartDelta({
-                      sessionID: currentText.sessionID,
-                      messageID: currentText.messageID,
-                      partID: currentText.id,
-                      field: "text",
-                      delta: value.text,
-                    })
-                  }
-                  break
-
-                case "text-end":
-                  if (currentText) {
-                    currentText.text = currentText.text.trimEnd()
-                    const textOutput = await Plugin.trigger(
-                      "experimental.text.complete",
-                      {
-                        sessionID: input.sessionID,
-                        messageID: input.assistantMessage.id,
-                        partID: currentText.id,
-                      },
-                      { text: currentText.text },
-                    )
-                    currentText.text = textOutput.text
-                    currentText.time = {
-                      start: Date.now(),
-                      end: Date.now(),
-                    }
-                    if (value.providerMetadata) currentText.metadata = value.providerMetadata
-                    await Session.updatePart(currentText)
-                  }
-                  currentText = undefined
-                  break
-
-                case "finish":
-                  break
-
-                default:
-                  log.info("unhandled", {
-                    ...value,
-                  })
-                  continue
+  type StreamEvent = Event
+
+  export class Service extends ServiceMap.Service<Service, Interface>()("@opencode/SessionProcessor") {}
+
+  export const layer: Layer.Layer<
+    Service,
+    never,
+    | Session.Service
+    | Config.Service
+    | Bus.Service
+    | Snapshot.Service
+    | Agent.Service
+    | LLM.Service
+    | Permission.Service
+    | Plugin.Service
+    | SessionStatus.Service
+  > = Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      const session = yield* Session.Service
+      const config = yield* Config.Service
+      const bus = yield* Bus.Service
+      const snapshot = yield* Snapshot.Service
+      const agents = yield* Agent.Service
+      const llm = yield* LLM.Service
+      const permission = yield* Permission.Service
+      const plugin = yield* Plugin.Service
+      const status = yield* SessionStatus.Service
+
+      const create = Effect.fn("SessionProcessor.create")(function* (input: Input) {
+        const ctx: ProcessorContext = {
+          assistantMessage: input.assistantMessage,
+          sessionID: input.sessionID,
+          model: input.model,
+          abort: input.abort,
+          toolcalls: {},
+          shouldBreak: false,
+          snapshot: undefined,
+          blocked: false,
+          needsCompaction: false,
+          currentText: undefined,
+          reasoningMap: {},
+        }
+
+        const parse = (e: unknown) =>
+          MessageV2.fromError(e, {
+            providerID: input.model.providerID,
+            aborted: input.abort.aborted,
+          })
+
+        const handleEvent = Effect.fn("SessionProcessor.handleEvent")(function* (value: StreamEvent) {
+          switch (value.type) {
+            case "start":
+              yield* status.set(ctx.sessionID, { type: "busy" })
+              return
+
+            case "reasoning-start":
+              if (value.id in ctx.reasoningMap) return
+              ctx.reasoningMap[value.id] = {
+                id: PartID.ascending(),
+                messageID: ctx.assistantMessage.id,
+                sessionID: ctx.assistantMessage.sessionID,
+                type: "reasoning",
+                text: "",
+                time: { start: Date.now() },
+                metadata: value.providerMetadata,
+              }
+              yield* session.updatePart(ctx.reasoningMap[value.id])
+              return
+
+            case "reasoning-delta":
+              if (!(value.id in ctx.reasoningMap)) return
+              ctx.reasoningMap[value.id].text += value.text
+              if (value.providerMetadata) ctx.reasoningMap[value.id].metadata = value.providerMetadata
+              yield* session.updatePartDelta({
+                sessionID: ctx.reasoningMap[value.id].sessionID,
+                messageID: ctx.reasoningMap[value.id].messageID,
+                partID: ctx.reasoningMap[value.id].id,
+                field: "text",
+                delta: value.text,
+              })
+              return
+
+            case "reasoning-end":
+              if (!(value.id in ctx.reasoningMap)) return
+              ctx.reasoningMap[value.id].text = ctx.reasoningMap[value.id].text.trimEnd()
+              ctx.reasoningMap[value.id].time = { ...ctx.reasoningMap[value.id].time, end: Date.now() }
+              if (value.providerMetadata) ctx.reasoningMap[value.id].metadata = value.providerMetadata
+              yield* session.updatePart(ctx.reasoningMap[value.id])
+              delete ctx.reasoningMap[value.id]
+              return
+
+            case "tool-input-start":
+              ctx.toolcalls[value.id] = (yield* session.updatePart({
+                id: ctx.toolcalls[value.id]?.id ?? PartID.ascending(),
+                messageID: ctx.assistantMessage.id,
+                sessionID: ctx.assistantMessage.sessionID,
+                type: "tool",
+                tool: value.toolName,
+                callID: value.id,
+                state: { status: "pending", input: {}, raw: "" },
+              })) as MessageV2.ToolPart
+              return
+
+            case "tool-input-delta":
+              return
+
+            case "tool-input-end":
+              return
+
+            case "tool-call": {
+              const match = ctx.toolcalls[value.toolCallId]
+              if (!match) return
+              ctx.toolcalls[value.toolCallId] = (yield* session.updatePart({
+                ...match,
+                tool: value.toolName,
+                state: { status: "running", input: value.input, time: { start: Date.now() } },
+                metadata: value.providerMetadata,
+              })) as MessageV2.ToolPart
+
+              const parts = yield* Effect.promise(() => MessageV2.parts(ctx.assistantMessage.id))
+              const recentParts = parts.slice(-DOOM_LOOP_THRESHOLD)
+
+              if (
+                recentParts.length !== DOOM_LOOP_THRESHOLD ||
+                !recentParts.every(
+                  (part) =>
+                    part.type === "tool" &&
+                    part.tool === value.toolName &&
+                    part.state.status !== "pending" &&
+                    JSON.stringify(part.state.input) === JSON.stringify(value.input),
+                )
+              ) {
+                return
               }
-              if (needsCompaction) break
+
+              const agent = yield* agents.get(ctx.assistantMessage.agent)
+              yield* permission.ask({
+                permission: "doom_loop",
+                patterns: [value.toolName],
+                sessionID: ctx.assistantMessage.sessionID,
+                metadata: { tool: value.toolName, input: value.input },
+                always: [value.toolName],
+                ruleset: agent.permission,
+              })
+              return
             }
-          } catch (e: any) {
-            log.error("process", {
-              error: e,
-              stack: JSON.stringify(e.stack),
-            })
-            const error = MessageV2.fromError(e, { providerID: input.model.providerID, aborted: input.abort.aborted })
-            if (MessageV2.ContextOverflowError.isInstance(error)) {
-              needsCompaction = true
-              Bus.publish(Session.Event.Error, {
-                sessionID: input.sessionID,
-                error,
+
+            case "tool-result": {
+              const match = ctx.toolcalls[value.toolCallId]
+              if (!match || match.state.status !== "running") return
+              yield* session.updatePart({
+                ...match,
+                state: {
+                  status: "completed",
+                  input: value.input ?? match.state.input,
+                  output: value.output.output,
+                  metadata: value.output.metadata,
+                  title: value.output.title,
+                  time: { start: match.state.time.start, end: Date.now() },
+                  attachments: value.output.attachments,
+                },
               })
-            } else {
-              const retry = SessionRetry.retryable(error)
-              if (retry !== undefined) {
-                attempt++
-                const delay = SessionRetry.delay(attempt, error.name === "APIError" ? error : undefined)
-                await SessionStatus.set(input.sessionID, {
-                  type: "retry",
-                  attempt,
-                  message: retry,
-                  next: Date.now() + delay,
-                })
-                await SessionRetry.sleep(delay, input.abort).catch(() => {})
-                continue
+              delete ctx.toolcalls[value.toolCallId]
+              return
+            }
+
+            case "tool-error": {
+              const match = ctx.toolcalls[value.toolCallId]
+              if (!match || match.state.status !== "running") return
+              yield* session.updatePart({
+                ...match,
+                state: {
+                  status: "error",
+                  input: value.input ?? match.state.input,
+                  error: value.error instanceof Error ? value.error.message : String(value.error),
+                  time: { start: match.state.time.start, end: Date.now() },
+                },
+              })
+              if (value.error instanceof Permission.RejectedError || value.error instanceof Question.RejectedError) {
+                ctx.blocked = ctx.shouldBreak
               }
-              input.assistantMessage.error = error
-              Bus.publish(Session.Event.Error, {
-                sessionID: input.assistantMessage.sessionID,
-                error: input.assistantMessage.error,
+              delete ctx.toolcalls[value.toolCallId]
+              return
+            }
+
+            case "error":
+              throw value.error
+
+            case "start-step":
+              ctx.snapshot = yield* snapshot.track()
+              yield* session.updatePart({
+                id: PartID.ascending(),
+                messageID: ctx.assistantMessage.id,
+                sessionID: ctx.sessionID,
+                snapshot: ctx.snapshot,
+                type: "step-start",
+              })
+              return
+
+            case "finish-step": {
+              const usage = Session.getUsage({
+                model: ctx.model,
+                usage: value.usage,
+                metadata: value.providerMetadata,
               })
-              await SessionStatus.set(input.sessionID, { type: "idle" })
+              ctx.assistantMessage.finish = value.finishReason
+              ctx.assistantMessage.cost += usage.cost
+              ctx.assistantMessage.tokens = usage.tokens
+              yield* session.updatePart({
+                id: PartID.ascending(),
+                reason: value.finishReason,
+                snapshot: yield* snapshot.track(),
+                messageID: ctx.assistantMessage.id,
+                sessionID: ctx.assistantMessage.sessionID,
+                type: "step-finish",
+                tokens: usage.tokens,
+                cost: usage.cost,
+              })
+              yield* session.updateMessage(ctx.assistantMessage)
+              if (ctx.snapshot) {
+                const patch = yield* snapshot.patch(ctx.snapshot)
+                if (patch.files.length) {
+                  yield* session.updatePart({
+                    id: PartID.ascending(),
+                    messageID: ctx.assistantMessage.id,
+                    sessionID: ctx.sessionID,
+                    type: "patch",
+                    hash: patch.hash,
+                    files: patch.files,
+                  })
+                }
+                ctx.snapshot = undefined
+              }
+              yield* Effect.promise(() =>
+                SessionSummary.summarize({
+                  sessionID: ctx.sessionID,
+                  messageID: ctx.assistantMessage.parentID,
+                }),
+              ).pipe(Effect.ignoreCause({ log: true, message: "session summary failed" }), Effect.forkDetach)
+              if (
+                !ctx.assistantMessage.summary &&
+                isOverflow({ cfg: yield* config.get(), tokens: usage.tokens, model: ctx.model })
+              ) {
+                ctx.needsCompaction = true
+              }
+              return
             }
+
+            case "text-start":
+              ctx.currentText = {
+                id: PartID.ascending(),
+                messageID: ctx.assistantMessage.id,
+                sessionID: ctx.assistantMessage.sessionID,
+                type: "text",
+                text: "",
+                time: { start: Date.now() },
+                metadata: value.providerMetadata,
+              }
+              yield* session.updatePart(ctx.currentText)
+              return
+
+            case "text-delta":
+              if (!ctx.currentText) return
+              ctx.currentText.text += value.text
+              if (value.providerMetadata) ctx.currentText.metadata = value.providerMetadata
+              yield* session.updatePartDelta({
+                sessionID: ctx.currentText.sessionID,
+                messageID: ctx.currentText.messageID,
+                partID: ctx.currentText.id,
+                field: "text",
+                delta: value.text,
+              })
+              return
+
+            case "text-end":
+              if (!ctx.currentText) return
+              ctx.currentText.text = ctx.currentText.text.trimEnd()
+              ctx.currentText.text = (yield* plugin.trigger(
+                "experimental.text.complete",
+                {
+                  sessionID: ctx.sessionID,
+                  messageID: ctx.assistantMessage.id,
+                  partID: ctx.currentText.id,
+                },
+                { text: ctx.currentText.text },
+              )).text
+              ctx.currentText.time = { start: Date.now(), end: Date.now() }
+              if (value.providerMetadata) ctx.currentText.metadata = value.providerMetadata
+              yield* session.updatePart(ctx.currentText)
+              ctx.currentText = undefined
+              return
+
+            case "finish":
+              return
+
+            default:
+              log.info("unhandled", { ...value })
+              return
           }
-          if (snapshot) {
-            const patch = await Snapshot.patch(snapshot)
+        })
+
+        const cleanup = Effect.fn("SessionProcessor.cleanup")(function* () {
+          if (ctx.snapshot) {
+            const patch = yield* snapshot.patch(ctx.snapshot)
             if (patch.files.length) {
-              await Session.updatePart({
+              yield* session.updatePart({
                 id: PartID.ascending(),
-                messageID: input.assistantMessage.id,
-                sessionID: input.sessionID,
+                messageID: ctx.assistantMessage.id,
+                sessionID: ctx.sessionID,
                 type: "patch",
                 hash: patch.hash,
                 files: patch.files,
               })
             }
-            snapshot = undefined
+            ctx.snapshot = undefined
           }
-          const p = await MessageV2.parts(input.assistantMessage.id)
-          for (const part of p) {
-            if (part.type === "tool" && part.state.status !== "completed" && part.state.status !== "error") {
-              await Session.updatePart({
-                ...part,
-                state: {
-                  ...part.state,
-                  status: "error",
-                  error: "Tool execution aborted",
-                  time: {
-                    start: Date.now(),
-                    end: Date.now(),
-                  },
-                },
-              })
-            }
+
+          if (ctx.currentText) {
+            const end = Date.now()
+            ctx.currentText.time = { start: ctx.currentText.time?.start ?? end, end }
+            yield* session.updatePart(ctx.currentText)
+            ctx.currentText = undefined
+          }
+
+          for (const part of Object.values(ctx.reasoningMap)) {
+            const end = Date.now()
+            yield* session.updatePart({
+              ...part,
+              time: { start: part.time.start ?? end, end },
+            })
           }
-          input.assistantMessage.time.completed = Date.now()
-          await Session.updateMessage(input.assistantMessage)
-          if (needsCompaction) return "compact"
-          if (blocked) return "stop"
-          if (input.assistantMessage.error) return "stop"
+          ctx.reasoningMap = {}
+
+          const parts = yield* Effect.promise(() => MessageV2.parts(ctx.assistantMessage.id))
+          for (const part of parts) {
+            if (part.type !== "tool" || part.state.status === "completed" || part.state.status === "error") continue
+            yield* session.updatePart({
+              ...part,
+              state: {
+                ...part.state,
+                status: "error",
+                error: "Tool execution aborted",
+                time: { start: Date.now(), end: Date.now() },
+              },
+            })
+          }
+          ctx.assistantMessage.time.completed = Date.now()
+          yield* session.updateMessage(ctx.assistantMessage)
+        })
+
+        const halt = Effect.fn("SessionProcessor.halt")(function* (e: unknown) {
+          log.error("process", { error: e, stack: JSON.stringify((e as any)?.stack) })
+          const error = parse(e)
+          if (MessageV2.ContextOverflowError.isInstance(error)) {
+            ctx.needsCompaction = true
+            yield* bus.publish(Session.Event.Error, { sessionID: ctx.sessionID, error })
+            return
+          }
+          ctx.assistantMessage.error = error
+          yield* bus.publish(Session.Event.Error, {
+            sessionID: ctx.assistantMessage.sessionID,
+            error: ctx.assistantMessage.error,
+          })
+          yield* status.set(ctx.sessionID, { type: "idle" })
+        })
+
+        const process = Effect.fn("SessionProcessor.process")(function* (streamInput: LLM.StreamInput) {
+          log.info("process")
+          ctx.needsCompaction = false
+          ctx.shouldBreak = (yield* config.get()).experimental?.continue_loop_on_deny !== true
+
+          yield* Effect.gen(function* () {
+            ctx.currentText = undefined
+            ctx.reasoningMap = {}
+            const stream = llm.stream(streamInput)
+
+            yield* stream.pipe(
+              Stream.tap((event) =>
+                Effect.gen(function* () {
+                  input.abort.throwIfAborted()
+                  yield* handleEvent(event)
+                }),
+              ),
+              Stream.takeUntil(() => ctx.needsCompaction),
+              Stream.runDrain,
+            )
+          }).pipe(
+            Effect.catchCauseIf(
+              (cause) => !Cause.hasInterruptsOnly(cause),
+              (cause) => Effect.fail(Cause.squash(cause)),
+            ),
+            Effect.retry(
+              SessionRetry.policy({
+                parse,
+                set: (info) =>
+                  status.set(ctx.sessionID, {
+                    type: "retry",
+                    attempt: info.attempt,
+                    message: info.message,
+                    next: info.next,
+                  }),
+              }),
+            ),
+            Effect.catchCause((cause) =>
+              Cause.hasInterruptsOnly(cause)
+                ? halt(new DOMException("Aborted", "AbortError"))
+                : halt(Cause.squash(cause)),
+            ),
+            Effect.ensuring(cleanup()),
+          )
+
+          if (input.abort.aborted && !ctx.assistantMessage.error) {
+            yield* abort()
+          }
+          if (ctx.needsCompaction) return "compact"
+          if (ctx.blocked || ctx.assistantMessage.error || input.abort.aborted) return "stop"
           return "continue"
+        })
+
+        const abort = Effect.fn("SessionProcessor.abort")(() =>
+          Effect.gen(function* () {
+            if (!ctx.assistantMessage.error) {
+              yield* halt(new DOMException("Aborted", "AbortError"))
+            }
+            if (!ctx.assistantMessage.time.completed) {
+              yield* cleanup()
+              return
+            }
+            yield* session.updateMessage(ctx.assistantMessage)
+          }),
+        )
+
+        return {
+          get message() {
+            return ctx.assistantMessage
+          },
+          partFromToolCall(toolCallID: string) {
+            return ctx.toolcalls[toolCallID]
+          },
+          abort,
+          process,
+        } satisfies Handle
+      })
+
+      return Service.of({ create })
+    }),
+  )
+
+  export const defaultLayer = Layer.unwrap(
+    Effect.sync(() =>
+      layer.pipe(
+        Layer.provide(Session.defaultLayer),
+        Layer.provide(Snapshot.defaultLayer),
+        Layer.provide(Agent.defaultLayer),
+        Layer.provide(LLM.defaultLayer),
+        Layer.provide(Permission.layer),
+        Layer.provide(Plugin.defaultLayer),
+        Layer.provide(SessionStatus.layer.pipe(Layer.provide(Bus.layer))),
+        Layer.provide(Bus.layer),
+        Layer.provide(Config.defaultLayer),
+      ),
+    ),
+  )
+
+  const { runPromise } = makeRuntime(Service, defaultLayer)
+
+  export async function create(input: Input): Promise<Info> {
+    const hit = await runPromise((svc) => svc.create(input))
+    return {
+      get message() {
+        return hit.message
+      },
+      partFromToolCall(toolCallID: string) {
+        return hit.partFromToolCall(toolCallID)
+      },
+      async process(streamInput: LLM.StreamInput) {
+        const exit = await Effect.runPromiseExit(hit.process(streamInput), { signal: input.abort })
+        if (Exit.isFailure(exit)) {
+          if (Cause.hasInterrupts(exit.cause) && input.abort.aborted) {
+            await Effect.runPromise(hit.abort())
+            return "stop"
+          }
+          throw Cause.squash(exit.cause)
         }
+        return exit.value
       },
     }
-    return result
   }
 }

packages/opencode/src/session/prompt.ts

@@ -594,7 +594,7 @@ export namespace SessionPrompt {
         session,
       })
 
-      const processor = SessionProcessor.create({
+      const processor = await SessionProcessor.create({
         assistantMessage: (await Session.updateMessage({
           id: MessageID.ascending(),
           parentID: lastUser.id,

packages/opencode/src/session/retry.ts

@@ -1,28 +1,18 @@
 import type { NamedError } from "@opencode-ai/util/error"
+import { Cause, Clock, Duration, Effect, Schedule } from "effect"
 import { MessageV2 } from "./message-v2"
 import { iife } from "@/util/iife"
 
 export namespace SessionRetry {
+  export type Err = ReturnType<NamedError["toObject"]>
+
   export const RETRY_INITIAL_DELAY = 2000
   export const RETRY_BACKOFF_FACTOR = 2
   export const RETRY_MAX_DELAY_NO_HEADERS = 30_000 // 30 seconds
   export const RETRY_MAX_DELAY = 2_147_483_647 // max 32-bit signed integer for setTimeout
 
-  export async function sleep(ms: number, signal: AbortSignal): Promise<void> {
-    return new Promise((resolve, reject) => {
-      const abortHandler = () => {
-        clearTimeout(timeout)
-        reject(new DOMException("Aborted", "AbortError"))
-      }
-      const timeout = setTimeout(
-        () => {
-          signal.removeEventListener("abort", abortHandler)
-          resolve()
-        },
-        Math.min(ms, RETRY_MAX_DELAY),
-      )
-      signal.addEventListener("abort", abortHandler, { once: true })
-    })
+  function cap(ms: number) {
+    return Math.min(ms, RETRY_MAX_DELAY)
   }
 
   export function delay(attempt: number, error?: MessageV2.APIError) {
@@ -33,7 +23,7 @@ export namespace SessionRetry {
         if (retryAfterMs) {
           const parsedMs = Number.parseFloat(retryAfterMs)
           if (!Number.isNaN(parsedMs)) {
-            return parsedMs
+            return cap(parsedMs)
           }
         }
 
@@ -42,23 +32,23 @@ export namespace SessionRetry {
           const parsedSeconds = Number.parseFloat(retryAfter)
           if (!Number.isNaN(parsedSeconds)) {
             // convert seconds to milliseconds
-            return Math.ceil(parsedSeconds * 1000)
+            return cap(Math.ceil(parsedSeconds * 1000))
           }
           // Try parsing as HTTP date format
           const parsed = Date.parse(retryAfter) - Date.now()
           if (!Number.isNaN(parsed) && parsed > 0) {
-            return Math.ceil(parsed)
+            return cap(Math.ceil(parsed))
           }
         }
 
-        return RETRY_INITIAL_DELAY * Math.pow(RETRY_BACKOFF_FACTOR, attempt - 1)
+        return cap(RETRY_INITIAL_DELAY * Math.pow(RETRY_BACKOFF_FACTOR, attempt - 1))
       }
     }
 
-    return Math.min(RETRY_INITIAL_DELAY * Math.pow(RETRY_BACKOFF_FACTOR, attempt - 1), RETRY_MAX_DELAY_NO_HEADERS)
+    return cap(Math.min(RETRY_INITIAL_DELAY * Math.pow(RETRY_BACKOFF_FACTOR, attempt - 1), RETRY_MAX_DELAY_NO_HEADERS))
   }
 
-  export function retryable(error: ReturnType<NamedError["toObject"]>) {
+  export function retryable(error: Err) {
     // context overflow errors should not be retried
     if (MessageV2.ContextOverflowError.isInstance(error)) return undefined
     if (MessageV2.APIError.isInstance(error)) {
@@ -80,22 +70,37 @@ export namespace SessionRetry {
         return undefined
       }
     })
-    try {
-      if (!json || typeof json !== "object") return undefined
-      const code = typeof json.code === "string" ? json.code : ""
+    if (!json || typeof json !== "object") return undefined
+    const code = typeof json.code === "string" ? json.code : ""
 
-      if (json.type === "error" && json.error?.type === "too_many_requests") {
-        return "Too Many Requests"
-      }
-      if (code.includes("exhausted") || code.includes("unavailable")) {
-        return "Provider is overloaded"
-      }
-      if (json.type === "error" && json.error?.code?.includes("rate_limit")) {
-        return "Rate Limited"
-      }
-      return JSON.stringify(json)
-    } catch {
-      return undefined
+    if (json.type === "error" && json.error?.type === "too_many_requests") {
+      return "Too Many Requests"
+    }
+    if (code.includes("exhausted") || code.includes("unavailable")) {
+      return "Provider is overloaded"
+    }
+    if (json.type === "error" && typeof json.error?.code === "string" && json.error.code.includes("rate_limit")) {
+      return "Rate Limited"
     }
+    return undefined
+  }
+
+  export function policy(opts: {
+    parse: (error: unknown) => Err
+    set: (input: { attempt: number; message: string; next: number }) => Effect.Effect<void>
+  }) {
+    return Schedule.fromStepWithMetadata(
+      Effect.succeed((meta: Schedule.InputMetadata<unknown>) => {
+        const error = opts.parse(meta.input)
+        const message = retryable(error)
+        if (!message) return Cause.done(meta.attempt)
+        return Effect.gen(function* () {
+          const wait = delay(meta.attempt, MessageV2.APIError.isInstance(error) ? error : undefined)
+          const now = yield* Clock.currentTimeMillis
+          yield* opts.set({ attempt: meta.attempt, message, next: now + wait })
+          return [meta.attempt, Duration.millis(wait)] as [number, Duration.Duration]
+        })
+      }),
+    )
   }
 }

packages/opencode/test/session/compaction.test.ts

@@ -1,18 +1,28 @@
 import { afterEach, describe, expect, mock, spyOn, test } from "bun:test"
+import { APICallError } from "ai"
+import { Cause, Effect, Exit, Layer, ManagedRuntime } from "effect"
+import * as Stream from "effect/Stream"
 import path from "path"
 import { Bus } from "../../src/bus"
+import { Config } from "../../src/config/config"
+import { Agent } from "../../src/agent/agent"
+import { LLM } from "../../src/session/llm"
 import { SessionCompaction } from "../../src/session/compaction"
 import { Token } from "../../src/util/token"
 import { Instance } from "../../src/project/instance"
 import { Log } from "../../src/util/log"
+import { Permission } from "../../src/permission"
+import { Plugin } from "../../src/plugin"
 import { tmpdir } from "../fixture/fixture"
 import { Session } from "../../src/session"
 import { MessageV2 } from "../../src/session/message-v2"
 import { MessageID, PartID, SessionID } from "../../src/session/schema"
+import { SessionStatus } from "../../src/session/status"
 import { ModelID, ProviderID } from "../../src/provider/schema"
 import type { Provider } from "../../src/provider/provider"
 import * as ProviderModule from "../../src/provider/provider"
 import * as SessionProcessorModule from "../../src/session/processor"
+import { Snapshot } from "../../src/snapshot"
 
 Log.init({ print: false })
 
@@ -121,12 +131,13 @@ async function tool(sessionID: SessionID, messageID: MessageID, tool: string, ou
 function fake(
   input: Parameters<(typeof SessionProcessorModule.SessionProcessor)["create"]>[0],
   result: "continue" | "compact",
-): ReturnType<(typeof SessionProcessorModule.SessionProcessor)["create"]> {
+) {
   const msg = input.assistantMessage
   return {
     get message() {
       return msg
     },
+    abort: Effect.fn("TestSessionProcessor.abort")(() => Effect.void),
     partFromToolCall() {
       return {
         id: PartID.ascending(),
@@ -138,10 +149,74 @@ function fake(
         state: { status: "pending", input: {}, raw: "" },
       }
     },
-    process: async () => result,
+    process: Effect.fn("TestSessionProcessor.process")(() => Effect.succeed(result)),
+  } satisfies SessionProcessorModule.SessionProcessor.Handle
+}
+
+function layer(result: "continue" | "compact") {
+  return Layer.succeed(
+    SessionProcessorModule.SessionProcessor.Service,
+    SessionProcessorModule.SessionProcessor.Service.of({
+      create: Effect.fn("TestSessionProcessor.create")((input) => Effect.succeed(fake(input, result))),
+    }),
+  )
+}
+
+function runtime(result: "continue" | "compact", plugin = Plugin.defaultLayer) {
+  const bus = Bus.layer
+  return ManagedRuntime.make(
+    Layer.mergeAll(SessionCompaction.layer, bus).pipe(
+      Layer.provide(Session.defaultLayer),
+      Layer.provide(layer(result)),
+      Layer.provide(Agent.defaultLayer),
+      Layer.provide(plugin),
+      Layer.provide(bus),
+      Layer.provide(Config.defaultLayer),
+    ),
+  )
+}
+
+function llm() {
+  const queue: Array<
+    Stream.Stream<LLM.Event, unknown> | ((input: LLM.StreamInput) => Stream.Stream<LLM.Event, unknown>)
+  > = []
+
+  return {
+    push(stream: Stream.Stream<LLM.Event, unknown> | ((input: LLM.StreamInput) => Stream.Stream<LLM.Event, unknown>)) {
+      queue.push(stream)
+    },
+    layer: Layer.succeed(
+      LLM.Service,
+      LLM.Service.of({
+        stream: (input) => {
+          const item = queue.shift() ?? Stream.empty
+          const stream = typeof item === "function" ? item(input) : item
+          return stream.pipe(Stream.mapEffect((event) => Effect.succeed(event)))
+        },
+      }),
+    ),
   }
 }
 
+function liveRuntime(layer: Layer.Layer<LLM.Service>) {
+  const bus = Bus.layer
+  const status = SessionStatus.layer.pipe(Layer.provide(bus))
+  const processor = SessionProcessorModule.SessionProcessor.layer
+  return ManagedRuntime.make(
+    Layer.mergeAll(SessionCompaction.layer.pipe(Layer.provide(processor)), processor, bus, status).pipe(
+      Layer.provide(Session.defaultLayer),
+      Layer.provide(Snapshot.defaultLayer),
+      Layer.provide(layer),
+      Layer.provide(Permission.layer),
+      Layer.provide(Agent.defaultLayer),
+      Layer.provide(Plugin.defaultLayer),
+      Layer.provide(status),
+      Layer.provide(bus),
+      Layer.provide(Config.defaultLayer),
+    ),
+  )
+}
+
 function wait(ms = 50) {
   return new Promise((resolve) => setTimeout(resolve, ms))
 }
@@ -154,6 +229,17 @@ function defer() {
   return { promise, resolve }
 }
 
+function plugin(ready: ReturnType<typeof defer>) {
+  return Layer.mock(Plugin.Service)({
+    trigger: <Name extends string, Input, Output>(name: Name, _input: Input, output: Output) => {
+      if (name !== "experimental.session.compacting") return Effect.succeed(output)
+      return Effect.sync(() => ready.resolve()).pipe(Effect.andThen(Effect.never), Effect.as(output))
+    },
+    list: () => Effect.succeed([]),
+    init: () => Effect.void,
+  })
+}
+
 describe("session.compaction.isOverflow", () => {
   test("returns true when token count exceeds usable context", async () => {
     await using tmp = await tmpdir()
@@ -429,37 +515,49 @@ describe("session.compaction.process", () => {
       directory: tmp.path,
       fn: async () => {
         spyOn(ProviderModule.Provider, "getModel").mockResolvedValue(createModel({ context: 100_000, output: 32_000 }))
-        spyOn(SessionProcessorModule.SessionProcessor, "create").mockImplementation((input) => fake(input, "continue"))
 
         const session = await Session.create({})
         const msg = await user(session.id, "hello")
         const msgs = await Session.messages({ sessionID: session.id })
         const done = defer()
         let seen = false
-        const unsub = Bus.subscribe(SessionCompaction.Event.Compacted, (evt) => {
-          if (evt.properties.sessionID !== session.id) return
-          seen = true
-          done.resolve()
-        })
-
-        const result = await SessionCompaction.process({
-          parentID: msg.id,
-          messages: msgs,
-          sessionID: session.id,
-          abort: new AbortController().signal,
-          auto: false,
-        })
-
-        await Promise.race([
-          done.promise,
-          wait(500).then(() => {
-            throw new Error("timed out waiting for compacted event")
-          }),
-        ])
-        unsub()
-
-        expect(result).toBe("continue")
-        expect(seen).toBe(true)
+        const rt = runtime("continue")
+        let unsub: (() => void) | undefined
+        try {
+          unsub = await rt.runPromise(
+            Bus.Service.use((svc) =>
+              svc.subscribeCallback(SessionCompaction.Event.Compacted, (evt) => {
+                if (evt.properties.sessionID !== session.id) return
+                seen = true
+                done.resolve()
+              }),
+            ),
+          )
+
+          const result = await rt.runPromise(
+            SessionCompaction.Service.use((svc) =>
+              svc.process({
+                parentID: msg.id,
+                messages: msgs,
+                sessionID: session.id,
+                abort: new AbortController().signal,
+                auto: false,
+              }),
+            ),
+          )
+
+          await Promise.race([
+            done.promise,
+            wait(500).then(() => {
+              throw new Error("timed out waiting for compacted event")
+            }),
+          ])
+          expect(result).toBe("continue")
+          expect(seen).toBe(true)
+        } finally {
+          unsub?.()
+          await rt.dispose()
+        }
       },
     })
   })
@@ -470,27 +568,36 @@ describe("session.compaction.process", () => {
       directory: tmp.path,
       fn: async () => {
         spyOn(ProviderModule.Provider, "getModel").mockResolvedValue(createModel({ context: 100_000, output: 32_000 }))
-        spyOn(SessionProcessorModule.SessionProcessor, "create").mockImplementation((input) => fake(input, "compact"))
 
         const session = await Session.create({})
         const msg = await user(session.id, "hello")
-        const result = await SessionCompaction.process({
-          parentID: msg.id,
-          messages: await Session.messages({ sessionID: session.id }),
-          sessionID: session.id,
-          abort: new AbortController().signal,
-          auto: false,
-        })
-
-        const summary = (await Session.messages({ sessionID: session.id })).find(
-          (msg) => msg.info.role === "assistant" && msg.info.summary,
-        )
-
-        expect(result).toBe("stop")
-        expect(summary?.info.role).toBe("assistant")
-        if (summary?.info.role === "assistant") {
-          expect(summary.info.finish).toBe("error")
-          expect(JSON.stringify(summary.info.error)).toContain("Session too large to compact")
+        const rt = runtime("compact")
+        try {
+          const msgs = await Session.messages({ sessionID: session.id })
+          const result = await rt.runPromise(
+            SessionCompaction.Service.use((svc) =>
+              svc.process({
+                parentID: msg.id,
+                messages: msgs,
+                sessionID: session.id,
+                abort: new AbortController().signal,
+                auto: false,
+              }),
+            ),
+          )
+
+          const summary = (await Session.messages({ sessionID: session.id })).find(
+            (msg) => msg.info.role === "assistant" && msg.info.summary,
+          )
+
+          expect(result).toBe("stop")
+          expect(summary?.info.role).toBe("assistant")
+          if (summary?.info.role === "assistant") {
+            expect(summary.info.finish).toBe("error")
+            expect(JSON.stringify(summary.info.error)).toContain("Session too large to compact")
+          }
+        } finally {
+          await rt.dispose()
         }
       },
     })
@@ -502,30 +609,38 @@ describe("session.compaction.process", () => {
       directory: tmp.path,
       fn: async () => {
         spyOn(ProviderModule.Provider, "getModel").mockResolvedValue(createModel({ context: 100_000, output: 32_000 }))
-        spyOn(SessionProcessorModule.SessionProcessor, "create").mockImplementation((input) => fake(input, "continue"))
 
         const session = await Session.create({})
         const msg = await user(session.id, "hello")
-
-        const result = await SessionCompaction.process({
-          parentID: msg.id,
-          messages: await Session.messages({ sessionID: session.id }),
-          sessionID: session.id,
-          abort: new AbortController().signal,
-          auto: true,
-        })
-
-        const msgs = await Session.messages({ sessionID: session.id })
-        const last = msgs.at(-1)
-
-        expect(result).toBe("continue")
-        expect(last?.info.role).toBe("user")
-        expect(last?.parts[0]).toMatchObject({
-          type: "text",
-          synthetic: true,
-        })
-        if (last?.parts[0]?.type === "text") {
-          expect(last.parts[0].text).toContain("Continue if you have next steps")
+        const rt = runtime("continue")
+        try {
+          const msgs = await Session.messages({ sessionID: session.id })
+          const result = await rt.runPromise(
+            SessionCompaction.Service.use((svc) =>
+              svc.process({
+                parentID: msg.id,
+                messages: msgs,
+                sessionID: session.id,
+                abort: new AbortController().signal,
+                auto: true,
+              }),
+            ),
+          )
+
+          const all = await Session.messages({ sessionID: session.id })
+          const last = all.at(-1)
+
+          expect(result).toBe("continue")
+          expect(last?.info.role).toBe("user")
+          expect(last?.parts[0]).toMatchObject({
+            type: "text",
+            synthetic: true,
+          })
+          if (last?.parts[0]?.type === "text") {
+            expect(last.parts[0].text).toContain("Continue if you have next steps")
+          }
+        } finally {
+          await rt.dispose()
         }
       },
     })
@@ -537,7 +652,6 @@ describe("session.compaction.process", () => {
       directory: tmp.path,
       fn: async () => {
         spyOn(ProviderModule.Provider, "getModel").mockResolvedValue(createModel({ context: 100_000, output: 32_000 }))
-        spyOn(SessionProcessorModule.SessionProcessor, "create").mockImplementation((input) => fake(input, "continue"))
 
         const session = await Session.create({})
         await user(session.id, "root")
@@ -552,24 +666,33 @@ describe("session.compaction.process", () => {
           url: "https://example.com/cat.png",
         })
         const msg = await user(session.id, "current")
-
-        const result = await SessionCompaction.process({
-          parentID: msg.id,
-          messages: await Session.messages({ sessionID: session.id }),
-          sessionID: session.id,
-          abort: new AbortController().signal,
-          auto: true,
-          overflow: true,
-        })
-
-        const last = (await Session.messages({ sessionID: session.id })).at(-1)
-
-        expect(result).toBe("continue")
-        expect(last?.info.role).toBe("user")
-        expect(last?.parts.some((part) => part.type === "file")).toBe(false)
-        expect(
-          last?.parts.some((part) => part.type === "text" && part.text.includes("Attached image/png: cat.png")),
-        ).toBe(true)
+        const rt = runtime("continue")
+        try {
+          const msgs = await Session.messages({ sessionID: session.id })
+          const result = await rt.runPromise(
+            SessionCompaction.Service.use((svc) =>
+              svc.process({
+                parentID: msg.id,
+                messages: msgs,
+                sessionID: session.id,
+                abort: new AbortController().signal,
+                auto: true,
+                overflow: true,
+              }),
+            ),
+          )
+
+          const last = (await Session.messages({ sessionID: session.id })).at(-1)
+
+          expect(result).toBe("continue")
+          expect(last?.info.role).toBe("user")
+          expect(last?.parts.some((part) => part.type === "file")).toBe(false)
+          expect(
+            last?.parts.some((part) => part.type === "text" && part.text.includes("Attached image/png: cat.png")),
+          ).toBe(true)
+        } finally {
+          await rt.dispose()
+        }
       },
     })
   })
@@ -580,27 +703,191 @@ describe("session.compaction.process", () => {
       directory: tmp.path,
       fn: async () => {
         spyOn(ProviderModule.Provider, "getModel").mockResolvedValue(createModel({ context: 100_000, output: 32_000 }))
-        spyOn(SessionProcessorModule.SessionProcessor, "create").mockImplementation((input) => fake(input, "continue"))
 
         const session = await Session.create({})
         await user(session.id, "earlier")
         const msg = await user(session.id, "current")
 
-        const result = await SessionCompaction.process({
-          parentID: msg.id,
-          messages: await Session.messages({ sessionID: session.id }),
-          sessionID: session.id,
-          abort: new AbortController().signal,
-          auto: true,
-          overflow: true,
-        })
+        const rt = runtime("continue")
+        try {
+          const msgs = await Session.messages({ sessionID: session.id })
+          const result = await rt.runPromise(
+            SessionCompaction.Service.use((svc) =>
+              svc.process({
+                parentID: msg.id,
+                messages: msgs,
+                sessionID: session.id,
+                abort: new AbortController().signal,
+                auto: true,
+                overflow: true,
+              }),
+            ),
+          )
+
+          const last = (await Session.messages({ sessionID: session.id })).at(-1)
+
+          expect(result).toBe("continue")
+          expect(last?.info.role).toBe("user")
+          if (last?.parts[0]?.type === "text") {
+            expect(last.parts[0].text).toContain("previous request exceeded the provider's size limit")
+          }
+        } finally {
+          await rt.dispose()
+        }
+      },
+    })
+  })
+
+  test("stops quickly when aborted during retry backoff", async () => {
+    const stub = llm()
+    const ready = defer()
+    stub.push(
+      Stream.fromAsyncIterable(
+        {
+          async *[Symbol.asyncIterator]() {
+            yield { type: "start" } as LLM.Event
+            throw new APICallError({
+              message: "boom",
+              url: "https://example.com/v1/chat/completions",
+              requestBodyValues: {},
+              statusCode: 503,
+              responseHeaders: { "retry-after-ms": "10000" },
+              responseBody: '{"error":"boom"}',
+              isRetryable: true,
+            })
+          },
+        },
+        (err) => err,
+      ),
+    )
+
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        spyOn(ProviderModule.Provider, "getModel").mockResolvedValue(createModel({ context: 100_000, output: 32_000 }))
+
+        const session = await Session.create({})
+        const msg = await user(session.id, "hello")
+        const msgs = await Session.messages({ sessionID: session.id })
+        const abort = new AbortController()
+        const rt = liveRuntime(stub.layer)
+        let off: (() => void) | undefined
+        let run: Promise<"continue" | "stop"> | undefined
+        try {
+          off = await rt.runPromise(
+            Bus.Service.use((svc) =>
+              svc.subscribeCallback(SessionStatus.Event.Status, (evt) => {
+                if (evt.properties.sessionID !== session.id) return
+                if (evt.properties.status.type !== "retry") return
+                ready.resolve()
+              }),
+            ),
+          )
+
+          run = rt
+            .runPromiseExit(
+              SessionCompaction.Service.use((svc) =>
+                svc.process({
+                  parentID: msg.id,
+                  messages: msgs,
+                  sessionID: session.id,
+                  abort: abort.signal,
+                  auto: false,
+                }),
+              ),
+              { signal: abort.signal },
+            )
+            .then((exit) => {
+              if (Exit.isFailure(exit)) {
+                if (Cause.hasInterrupts(exit.cause) && abort.signal.aborted) return "stop"
+                throw Cause.squash(exit.cause)
+              }
+              return exit.value
+            })
+
+          await Promise.race([
+            ready.promise,
+            wait(1000).then(() => {
+              throw new Error("timed out waiting for retry status")
+            }),
+          ])
+
+          const start = Date.now()
+          abort.abort()
+          const result = await Promise.race([
+            run.then((value) => ({ kind: "done" as const, value, ms: Date.now() - start })),
+            wait(250).then(() => ({ kind: "timeout" as const })),
+          ])
+
+          expect(result.kind).toBe("done")
+          if (result.kind === "done") {
+            expect(result.value).toBe("stop")
+            expect(result.ms).toBeLessThan(250)
+          }
+        } finally {
+          off?.()
+          abort.abort()
+          await rt.dispose()
+          await run?.catch(() => undefined)
+        }
+      },
+    })
+  })
+
+  test("does not leave a summary assistant when aborted before processor setup", async () => {
+    const ready = defer()
 
-        const last = (await Session.messages({ sessionID: session.id })).at(-1)
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        spyOn(ProviderModule.Provider, "getModel").mockResolvedValue(createModel({ context: 100_000, output: 32_000 }))
 
-        expect(result).toBe("continue")
-        expect(last?.info.role).toBe("user")
-        if (last?.parts[0]?.type === "text") {
-          expect(last.parts[0].text).toContain("previous request exceeded the provider's size limit")
+        const session = await Session.create({})
+        const msg = await user(session.id, "hello")
+        const msgs = await Session.messages({ sessionID: session.id })
+        const abort = new AbortController()
+        const rt = runtime("continue", plugin(ready))
+        let run: Promise<"continue" | "stop"> | undefined
+        try {
+          run = rt
+            .runPromiseExit(
+              SessionCompaction.Service.use((svc) =>
+                svc.process({
+                  parentID: msg.id,
+                  messages: msgs,
+                  sessionID: session.id,
+                  abort: abort.signal,
+                  auto: false,
+                }),
+              ),
+              { signal: abort.signal },
+            )
+            .then((exit) => {
+              if (Exit.isFailure(exit)) {
+                if (Cause.hasInterrupts(exit.cause) && abort.signal.aborted) return "stop"
+                throw Cause.squash(exit.cause)
+              }
+              return exit.value
+            })
+
+          await Promise.race([
+            ready.promise,
+            wait(1000).then(() => {
+              throw new Error("timed out waiting for compaction hook")
+            }),
+          ])
+
+          abort.abort()
+          expect(await run).toBe("stop")
+
+          const all = await Session.messages({ sessionID: session.id })
+          expect(all.some((msg) => msg.info.role === "assistant" && msg.info.summary)).toBe(false)
+        } finally {
+          abort.abort()
+          await rt.dispose()
+          await run?.catch(() => undefined)
         }
       },
     })

packages/opencode/test/session/processor-effect.test.ts

@@ -0,0 +1,838 @@
+import { NodeFileSystem } from "@effect/platform-node"
+import { expect } from "bun:test"
+import { APICallError } from "ai"
+import { Effect, Layer, ServiceMap } from "effect"
+import * as Stream from "effect/Stream"
+import path from "path"
+import type { Agent } from "../../src/agent/agent"
+import { Agent as AgentSvc } from "../../src/agent/agent"
+import { Bus } from "../../src/bus"
+import { Config } from "../../src/config/config"
+import { Permission } from "../../src/permission"
+import { Plugin } from "../../src/plugin"
+import { Instance } from "../../src/project/instance"
+import type { Provider } from "../../src/provider/provider"
+import { ModelID, ProviderID } from "../../src/provider/schema"
+import { Session } from "../../src/session"
+import { LLM } from "../../src/session/llm"
+import { MessageV2 } from "../../src/session/message-v2"
+import { SessionProcessor } from "../../src/session/processor"
+import { MessageID, PartID, SessionID } from "../../src/session/schema"
+import { SessionStatus } from "../../src/session/status"
+import { Snapshot } from "../../src/snapshot"
+import { Log } from "../../src/util/log"
+import * as CrossSpawnSpawner from "../../src/effect/cross-spawn-spawner"
+import { provideTmpdirInstance } from "../fixture/fixture"
+import { testEffect } from "../lib/effect"
+
+Log.init({ print: false })
+
+const ref = {
+  providerID: ProviderID.make("test"),
+  modelID: ModelID.make("test-model"),
+}
+
+type Script = Stream.Stream<LLM.Event, unknown> | ((input: LLM.StreamInput) => Stream.Stream<LLM.Event, unknown>)
+
+class TestLLM extends ServiceMap.Service<
+  TestLLM,
+  {
+    readonly push: (stream: Script) => Effect.Effect<void>
+    readonly reply: (...items: LLM.Event[]) => Effect.Effect<void>
+    readonly calls: Effect.Effect<number>
+    readonly inputs: Effect.Effect<LLM.StreamInput[]>
+  }
+>()("@test/SessionProcessorLLM") {}
+
+function stream(...items: LLM.Event[]) {
+  return Stream.make(...items)
+}
+
+function usage(input = 1, output = 1, total = input + output) {
+  return {
+    inputTokens: input,
+    outputTokens: output,
+    totalTokens: total,
+    inputTokenDetails: {
+      noCacheTokens: undefined,
+      cacheReadTokens: undefined,
+      cacheWriteTokens: undefined,
+    },
+    outputTokenDetails: {
+      textTokens: undefined,
+      reasoningTokens: undefined,
+    },
+  }
+}
+
+function start(): LLM.Event {
+  return { type: "start" }
+}
+
+function textStart(id = "t"): LLM.Event {
+  return { type: "text-start", id }
+}
+
+function textDelta(id: string, text: string): LLM.Event {
+  return { type: "text-delta", id, text }
+}
+
+function textEnd(id = "t"): LLM.Event {
+  return { type: "text-end", id }
+}
+
+function reasoningStart(id: string): LLM.Event {
+  return { type: "reasoning-start", id }
+}
+
+function reasoningDelta(id: string, text: string): LLM.Event {
+  return { type: "reasoning-delta", id, text }
+}
+
+function reasoningEnd(id: string): LLM.Event {
+  return { type: "reasoning-end", id }
+}
+
+function finishStep(): LLM.Event {
+  return {
+    type: "finish-step",
+    finishReason: "stop",
+    rawFinishReason: "stop",
+    response: { id: "res", modelId: "test-model", timestamp: new Date() },
+    providerMetadata: undefined,
+    usage: usage(),
+  }
+}
+
+function finish(): LLM.Event {
+  return { type: "finish", finishReason: "stop", rawFinishReason: "stop", totalUsage: usage() }
+}
+
+function toolInputStart(id: string, toolName: string): LLM.Event {
+  return { type: "tool-input-start", id, toolName }
+}
+
+function toolCall(toolCallId: string, toolName: string, input: unknown): LLM.Event {
+  return { type: "tool-call", toolCallId, toolName, input }
+}
+
+function fail<E>(err: E, ...items: LLM.Event[]) {
+  return stream(...items).pipe(Stream.concat(Stream.fail(err)))
+}
+
+function wait(abort: AbortSignal) {
+  return Effect.promise(
+    () =>
+      new Promise<void>((done) => {
+        abort.addEventListener("abort", () => done(), { once: true })
+      }),
+  )
+}
+
+function hang(input: LLM.StreamInput, ...items: LLM.Event[]) {
+  return stream(...items).pipe(
+    Stream.concat(
+      Stream.unwrap(wait(input.abort).pipe(Effect.as(Stream.fail(new DOMException("Aborted", "AbortError"))))),
+    ),
+  )
+}
+
+function model(context: number): Provider.Model {
+  return {
+    id: "test-model",
+    providerID: "test",
+    name: "Test",
+    limit: { context, output: 10 },
+    cost: { input: 0, output: 0, cache: { read: 0, write: 0 } },
+    capabilities: {
+      toolcall: true,
+      attachment: false,
+      reasoning: false,
+      temperature: true,
+      input: { text: true, image: false, audio: false, video: false },
+      output: { text: true, image: false, audio: false, video: false },
+    },
+    api: { npm: "@ai-sdk/anthropic" },
+    options: {},
+  } as Provider.Model
+}
+
+function agent(): Agent.Info {
+  return {
+    name: "build",
+    mode: "primary",
+    options: {},
+    permission: [{ permission: "*", pattern: "*", action: "allow" }],
+  }
+}
+
+function defer<T>() {
+  let resolve!: (value: T | PromiseLike<T>) => void
+  const promise = new Promise<T>((done) => {
+    resolve = done
+  })
+  return { promise, resolve }
+}
+
+const user = Effect.fn("TestSession.user")(function* (sessionID: SessionID, text: string) {
+  const session = yield* Session.Service
+  const msg = yield* session.updateMessage({
+    id: MessageID.ascending(),
+    role: "user",
+    sessionID,
+    agent: "build",
+    model: ref,
+    time: { created: Date.now() },
+  })
+  yield* session.updatePart({
+    id: PartID.ascending(),
+    messageID: msg.id,
+    sessionID,
+    type: "text",
+    text,
+  })
+  return msg
+})
+
+const assistant = Effect.fn("TestSession.assistant")(function* (
+  sessionID: SessionID,
+  parentID: MessageID,
+  root: string,
+) {
+  const session = yield* Session.Service
+  const msg: MessageV2.Assistant = {
+    id: MessageID.ascending(),
+    role: "assistant",
+    sessionID,
+    mode: "build",
+    agent: "build",
+    path: { cwd: root, root },
+    cost: 0,
+    tokens: {
+      total: 0,
+      input: 0,
+      output: 0,
+      reasoning: 0,
+      cache: { read: 0, write: 0 },
+    },
+    modelID: ref.modelID,
+    providerID: ref.providerID,
+    parentID,
+    time: { created: Date.now() },
+    finish: "end_turn",
+  }
+  yield* session.updateMessage(msg)
+  return msg
+})
+
+const llm = Layer.unwrap(
+  Effect.gen(function* () {
+    const queue: Script[] = []
+    const inputs: LLM.StreamInput[] = []
+    let calls = 0
+
+    const push = Effect.fn("TestLLM.push")((item: Script) => {
+      queue.push(item)
+      return Effect.void
+    })
+
+    const reply = Effect.fn("TestLLM.reply")((...items: LLM.Event[]) => push(stream(...items)))
+    return Layer.mergeAll(
+      Layer.succeed(
+        LLM.Service,
+        LLM.Service.of({
+          stream: (input) => {
+            calls += 1
+            inputs.push(input)
+            const item = queue.shift() ?? Stream.empty
+            return typeof item === "function" ? item(input) : item
+          },
+        }),
+      ),
+      Layer.succeed(
+        TestLLM,
+        TestLLM.of({
+          push,
+          reply,
+          calls: Effect.sync(() => calls),
+          inputs: Effect.sync(() => [...inputs]),
+        }),
+      ),
+    )
+  }),
+)
+
+const status = SessionStatus.layer.pipe(Layer.provideMerge(Bus.layer))
+const infra = Layer.mergeAll(NodeFileSystem.layer, CrossSpawnSpawner.defaultLayer)
+const deps = Layer.mergeAll(
+  Session.defaultLayer,
+  Snapshot.defaultLayer,
+  AgentSvc.defaultLayer,
+  Permission.layer,
+  Plugin.defaultLayer,
+  Config.defaultLayer,
+  status,
+  llm,
+).pipe(Layer.provideMerge(infra))
+const env = SessionProcessor.layer.pipe(Layer.provideMerge(deps))
+
+const it = testEffect(env)
+
+it.effect("session.processor effect tests capture llm input cleanly", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+
+        yield* test.reply(start(), textStart(), textDelta("t", "hello"), textEnd(), finishStep(), finish())
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "hi")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(100)
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const input = {
+          user: {
+            id: parent.id,
+            sessionID: chat.id,
+            role: "user",
+            time: parent.time,
+            agent: parent.agent,
+            model: { providerID: ref.providerID, modelID: ref.modelID },
+          } satisfies MessageV2.User,
+          sessionID: chat.id,
+          model: mdl,
+          agent: agent(),
+          system: [],
+          abort: abort.signal,
+          messages: [{ role: "user", content: "hi" }],
+          tools: {},
+        } satisfies LLM.StreamInput
+
+        const value = yield* handle.process(input)
+        const parts = yield* Effect.promise(() => MessageV2.parts(msg.id))
+        const calls = yield* test.calls
+        const inputs = yield* test.inputs
+
+        expect(value).toBe("continue")
+        expect(calls).toBe(1)
+        expect(inputs).toHaveLength(1)
+        expect(inputs[0].messages).toStrictEqual([{ role: "user", content: "hi" }])
+        expect(parts.some((part) => part.type === "text" && part.text === "hello")).toBe(true)
+      }),
+    { git: true },
+  )
+})
+
+it.effect("session.processor effect tests stop after token overflow requests compaction", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+
+        yield* test.reply(
+          start(),
+          {
+            type: "finish-step",
+            finishReason: "stop",
+            rawFinishReason: "stop",
+            response: { id: "res", modelId: "test-model", timestamp: new Date() },
+            providerMetadata: undefined,
+            usage: usage(100, 0, 100),
+          },
+          textStart(),
+          textDelta("t", "after"),
+          textEnd(),
+        )
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "compact")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(20)
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const value = yield* handle.process({
+          user: {
+            id: parent.id,
+            sessionID: chat.id,
+            role: "user",
+            time: parent.time,
+            agent: parent.agent,
+            model: { providerID: ref.providerID, modelID: ref.modelID },
+          } satisfies MessageV2.User,
+          sessionID: chat.id,
+          model: mdl,
+          agent: agent(),
+          system: [],
+          abort: abort.signal,
+          messages: [{ role: "user", content: "compact" }],
+          tools: {},
+        })
+
+        const parts = yield* Effect.promise(() => MessageV2.parts(msg.id))
+
+        expect(value).toBe("compact")
+        expect(parts.some((part) => part.type === "text")).toBe(false)
+        expect(parts.some((part) => part.type === "step-finish")).toBe(true)
+      }),
+    { git: true },
+  )
+})
+
+it.effect("session.processor effect tests reset reasoning state across retries", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+
+        yield* test.push(
+          fail(
+            new APICallError({
+              message: "boom",
+              url: "https://example.com/v1/chat/completions",
+              requestBodyValues: {},
+              statusCode: 503,
+              responseHeaders: { "retry-after-ms": "0" },
+              responseBody: '{"error":"boom"}',
+              isRetryable: true,
+            }),
+            start(),
+            reasoningStart("r"),
+            reasoningDelta("r", "one"),
+          ),
+        )
+
+        yield* test.reply(
+          start(),
+          reasoningStart("r"),
+          reasoningDelta("r", "two"),
+          reasoningEnd("r"),
+          finishStep(),
+          finish(),
+        )
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "reason")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(100)
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const value = yield* handle.process({
+          user: {
+            id: parent.id,
+            sessionID: chat.id,
+            role: "user",
+            time: parent.time,
+            agent: parent.agent,
+            model: { providerID: ref.providerID, modelID: ref.modelID },
+          } satisfies MessageV2.User,
+          sessionID: chat.id,
+          model: mdl,
+          agent: agent(),
+          system: [],
+          abort: abort.signal,
+          messages: [{ role: "user", content: "reason" }],
+          tools: {},
+        })
+
+        const parts = yield* Effect.promise(() => MessageV2.parts(msg.id))
+        const reasoning = parts.filter((part): part is MessageV2.ReasoningPart => part.type === "reasoning")
+
+        expect(value).toBe("continue")
+        expect(yield* test.calls).toBe(2)
+        expect(reasoning.some((part) => part.text === "two")).toBe(true)
+        expect(reasoning.some((part) => part.text === "onetwo")).toBe(false)
+      }),
+    { git: true },
+  )
+})
+
+it.effect("session.processor effect tests do not retry unknown json errors", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+
+        yield* test.push(fail({ error: { message: "no_kv_space" } }, start()))
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "json")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(100)
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const value = yield* handle.process({
+          user: {
+            id: parent.id,
+            sessionID: chat.id,
+            role: "user",
+            time: parent.time,
+            agent: parent.agent,
+            model: { providerID: ref.providerID, modelID: ref.modelID },
+          } satisfies MessageV2.User,
+          sessionID: chat.id,
+          model: mdl,
+          agent: agent(),
+          system: [],
+          abort: abort.signal,
+          messages: [{ role: "user", content: "json" }],
+          tools: {},
+        })
+
+        expect(value).toBe("stop")
+        expect(yield* test.calls).toBe(1)
+        expect(yield* test.inputs).toHaveLength(1)
+        expect(handle.message.error?.name).toBe("UnknownError")
+      }),
+    { git: true },
+  )
+})
+
+it.effect("session.processor effect tests retry recognized structured json errors", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+
+        yield* test.push(fail({ type: "error", error: { type: "too_many_requests" } }, start()))
+        yield* test.reply(start(), textStart(), textDelta("t", "after"), textEnd(), finishStep(), finish())
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "retry json")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(100)
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const value = yield* handle.process({
+          user: {
+            id: parent.id,
+            sessionID: chat.id,
+            role: "user",
+            time: parent.time,
+            agent: parent.agent,
+            model: { providerID: ref.providerID, modelID: ref.modelID },
+          } satisfies MessageV2.User,
+          sessionID: chat.id,
+          model: mdl,
+          agent: agent(),
+          system: [],
+          abort: abort.signal,
+          messages: [{ role: "user", content: "retry json" }],
+          tools: {},
+        })
+
+        const parts = yield* Effect.promise(() => MessageV2.parts(msg.id))
+
+        expect(value).toBe("continue")
+        expect(yield* test.calls).toBe(2)
+        expect(parts.some((part) => part.type === "text" && part.text === "after")).toBe(true)
+        expect(handle.message.error).toBeUndefined()
+      }),
+    { git: true },
+  )
+})
+
+it.effect("session.processor effect tests publish retry status updates", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+        const bus = yield* Bus.Service
+
+        yield* test.push(
+          fail(
+            new APICallError({
+              message: "boom",
+              url: "https://example.com/v1/chat/completions",
+              requestBodyValues: {},
+              statusCode: 503,
+              responseHeaders: { "retry-after-ms": "0" },
+              responseBody: '{"error":"boom"}',
+              isRetryable: true,
+            }),
+            start(),
+          ),
+        )
+        yield* test.reply(start(), finishStep(), finish())
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "retry")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(100)
+        const states: number[] = []
+        const off = yield* bus.subscribeCallback(SessionStatus.Event.Status, (evt) => {
+          if (evt.properties.sessionID !== chat.id) return
+          if (evt.properties.status.type === "retry") states.push(evt.properties.status.attempt)
+        })
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const value = yield* handle.process({
+          user: {
+            id: parent.id,
+            sessionID: chat.id,
+            role: "user",
+            time: parent.time,
+            agent: parent.agent,
+            model: { providerID: ref.providerID, modelID: ref.modelID },
+          } satisfies MessageV2.User,
+          sessionID: chat.id,
+          model: mdl,
+          agent: agent(),
+          system: [],
+          abort: abort.signal,
+          messages: [{ role: "user", content: "retry" }],
+          tools: {},
+        })
+
+        off()
+
+        expect(value).toBe("continue")
+        expect(yield* test.calls).toBe(2)
+        expect(states).toStrictEqual([1])
+      }),
+    { git: true },
+  )
+})
+
+it.effect("session.processor effect tests compact on structured context overflow", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+
+        yield* test.push(fail({ type: "error", error: { code: "context_length_exceeded" } }, start()))
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "compact json")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(100)
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const value = yield* handle.process({
+          user: {
+            id: parent.id,
+            sessionID: chat.id,
+            role: "user",
+            time: parent.time,
+            agent: parent.agent,
+            model: { providerID: ref.providerID, modelID: ref.modelID },
+          } satisfies MessageV2.User,
+          sessionID: chat.id,
+          model: mdl,
+          agent: agent(),
+          system: [],
+          abort: abort.signal,
+          messages: [{ role: "user", content: "compact json" }],
+          tools: {},
+        })
+
+        expect(value).toBe("compact")
+        expect(yield* test.calls).toBe(1)
+        expect(handle.message.error).toBeUndefined()
+      }),
+    { git: true },
+  )
+})
+
+it.effect("session.processor effect tests mark pending tools as aborted on cleanup", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const ready = defer<void>()
+        const seen = defer<void>()
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+
+        yield* test.push((input) =>
+          hang(input, start(), toolInputStart("tool-1", "bash"), toolCall("tool-1", "bash", { cmd: "pwd" })).pipe(
+            Stream.tap((event) => (event.type === "tool-call" ? Effect.sync(() => ready.resolve()) : Effect.void)),
+          ),
+        )
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "tool abort")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(100)
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const run = Effect.runPromise(
+          handle.process({
+            user: {
+              id: parent.id,
+              sessionID: chat.id,
+              role: "user",
+              time: parent.time,
+              agent: parent.agent,
+              model: { providerID: ref.providerID, modelID: ref.modelID },
+            } satisfies MessageV2.User,
+            sessionID: chat.id,
+            model: mdl,
+            agent: agent(),
+            system: [],
+            abort: abort.signal,
+            messages: [{ role: "user", content: "tool abort" }],
+            tools: {},
+          }),
+        )
+
+        yield* Effect.promise(() => ready.promise)
+        abort.abort()
+
+        const value = yield* Effect.promise(() => run)
+        const parts = yield* Effect.promise(() => MessageV2.parts(msg.id))
+        const tool = parts.find((part): part is MessageV2.ToolPart => part.type === "tool")
+
+        expect(value).toBe("stop")
+        expect(yield* test.calls).toBe(1)
+        expect(tool?.state.status).toBe("error")
+        if (tool?.state.status === "error") {
+          expect(tool.state.error).toBe("Tool execution aborted")
+          expect(tool.state.time.end).toBeDefined()
+        }
+      }),
+    { git: true },
+  )
+})
+
+it.effect("session.processor effect tests record aborted errors and idle state", () => {
+  return provideTmpdirInstance(
+    (dir) =>
+      Effect.gen(function* () {
+        const ready = defer<void>()
+        const seen = defer<void>()
+        const test = yield* TestLLM
+        const processors = yield* SessionProcessor.Service
+        const session = yield* Session.Service
+        const bus = yield* Bus.Service
+        const status = yield* SessionStatus.Service
+
+        yield* test.push((input) =>
+          hang(input, start()).pipe(
+            Stream.tap((event) => (event.type === "start" ? Effect.sync(() => ready.resolve()) : Effect.void)),
+          ),
+        )
+
+        const chat = yield* session.create({})
+        const parent = yield* user(chat.id, "abort")
+        const msg = yield* assistant(chat.id, parent.id, path.resolve(dir))
+        const abort = new AbortController()
+        const mdl = model(100)
+        const errs: string[] = []
+        const off = yield* bus.subscribeCallback(Session.Event.Error, (evt) => {
+          if (evt.properties.sessionID !== chat.id) return
+          if (!evt.properties.error) return
+          errs.push(evt.properties.error.name)
+          seen.resolve()
+        })
+        const handle = yield* processors.create({
+          assistantMessage: msg,
+          sessionID: chat.id,
+          model: mdl,
+          abort: abort.signal,
+        })
+
+        const run = Effect.runPromise(
+          handle.process({
+            user: {
+              id: parent.id,
+              sessionID: chat.id,
+              role: "user",
+              time: parent.time,
+              agent: parent.agent,
+              model: { providerID: ref.providerID, modelID: ref.modelID },
+            } satisfies MessageV2.User,
+            sessionID: chat.id,
+            model: mdl,
+            agent: agent(),
+            system: [],
+            abort: abort.signal,
+            messages: [{ role: "user", content: "abort" }],
+            tools: {},
+          }),
+        )
+
+        yield* Effect.promise(() => ready.promise)
+        abort.abort()
+
+        const value = yield* Effect.promise(() => run)
+        yield* Effect.promise(() => seen.promise)
+        const stored = yield* Effect.promise(() => MessageV2.get({ sessionID: chat.id, messageID: msg.id }))
+        const state = yield* status.get(chat.id)
+        off()
+
+        expect(value).toBe("stop")
+        expect(handle.message.error?.name).toBe("MessageAbortedError")
+        expect(stored.info.role).toBe("assistant")
+        if (stored.info.role === "assistant") {
+          expect(stored.info.error?.name).toBe("MessageAbortedError")
+        }
+        expect(state).toMatchObject({ type: "idle" })
+        expect(errs).toContain("MessageAbortedError")
+      }),
+    { git: true },
+  )
+})

packages/opencode/test/session/prompt.test.ts

@@ -12,6 +12,83 @@ import { tmpdir } from "../fixture/fixture"
 
 Log.init({ print: false })
 
+function defer<T>() {
+  let resolve!: (value: T | PromiseLike<T>) => void
+  const promise = new Promise<T>((done) => {
+    resolve = done
+  })
+  return { promise, resolve }
+}
+
+function chat(text: string) {
+  const payload =
+    [
+      `data: ${JSON.stringify({
+        id: "chatcmpl-1",
+        object: "chat.completion.chunk",
+        choices: [{ delta: { role: "assistant" } }],
+      })}`,
+      `data: ${JSON.stringify({
+        id: "chatcmpl-1",
+        object: "chat.completion.chunk",
+        choices: [{ delta: { content: text } }],
+      })}`,
+      `data: ${JSON.stringify({
+        id: "chatcmpl-1",
+        object: "chat.completion.chunk",
+        choices: [{ delta: {}, finish_reason: "stop" }],
+      })}`,
+      "data: [DONE]",
+    ].join("\n\n") + "\n\n"
+
+  const encoder = new TextEncoder()
+  return new ReadableStream<Uint8Array>({
+    start(ctrl) {
+      ctrl.enqueue(encoder.encode(payload))
+      ctrl.close()
+    },
+  })
+}
+
+function hanging(ready: () => void) {
+  const encoder = new TextEncoder()
+  let timer: ReturnType<typeof setTimeout> | undefined
+  const first =
+    `data: ${JSON.stringify({
+      id: "chatcmpl-1",
+      object: "chat.completion.chunk",
+      choices: [{ delta: { role: "assistant" } }],
+    })}` + "\n\n"
+  const rest =
+    [
+      `data: ${JSON.stringify({
+        id: "chatcmpl-1",
+        object: "chat.completion.chunk",
+        choices: [{ delta: { content: "late" } }],
+      })}`,
+      `data: ${JSON.stringify({
+        id: "chatcmpl-1",
+        object: "chat.completion.chunk",
+        choices: [{ delta: {}, finish_reason: "stop" }],
+      })}`,
+      "data: [DONE]",
+    ].join("\n\n") + "\n\n"
+
+  return new ReadableStream<Uint8Array>({
+    start(ctrl) {
+      ctrl.enqueue(encoder.encode(first))
+      ready()
+      timer = setTimeout(() => {
+        ctrl.enqueue(encoder.encode(rest))
+        ctrl.close()
+      }, 10000)
+    },
+    cancel() {
+      if (timer) clearTimeout(timer)
+    },
+  })
+}
+
 describe("session.prompt missing file", () => {
   test("does not fail the prompt when a file part is missing", async () => {
     await using tmp = await tmpdir({
@@ -149,6 +226,159 @@ describe("session.prompt special characters", () => {
   })
 })
 
+describe("session.prompt regression", () => {
+  test("does not loop empty assistant turns for a simple reply", async () => {
+    let calls = 0
+    const server = Bun.serve({
+      port: 0,
+      fetch(req) {
+        const url = new URL(req.url)
+        if (!url.pathname.endsWith("/chat/completions")) {
+          return new Response("not found", { status: 404 })
+        }
+        calls++
+        return new Response(chat("packages/opencode/src/session/processor.ts"), {
+          status: 200,
+          headers: { "Content-Type": "text/event-stream" },
+        })
+      },
+    })
+
+    try {
+      await using tmp = await tmpdir({
+        git: true,
+        init: async (dir) => {
+          await Bun.write(
+            path.join(dir, "opencode.json"),
+            JSON.stringify({
+              $schema: "https://opencode.ai/config.json",
+              enabled_providers: ["alibaba"],
+              provider: {
+                alibaba: {
+                  options: {
+                    apiKey: "test-key",
+                    baseURL: `${server.url.origin}/v1`,
+                  },
+                },
+              },
+              agent: {
+                build: {
+                  model: "alibaba/qwen-plus",
+                },
+              },
+            }),
+          )
+        },
+      })
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          const session = await Session.create({ title: "Prompt regression" })
+          const result = await SessionPrompt.prompt({
+            sessionID: session.id,
+            agent: "build",
+            parts: [{ type: "text", text: "Where is SessionProcessor?" }],
+          })
+
+          expect(result.info.role).toBe("assistant")
+          expect(result.parts.some((part) => part.type === "text" && part.text.includes("processor.ts"))).toBe(true)
+
+          const msgs = await Session.messages({ sessionID: session.id })
+          expect(msgs.filter((msg) => msg.info.role === "assistant")).toHaveLength(1)
+          expect(calls).toBe(1)
+        },
+      })
+    } finally {
+      server.stop(true)
+    }
+  })
+
+  test("records aborted errors when prompt is cancelled mid-stream", async () => {
+    const ready = defer<void>()
+    const server = Bun.serve({
+      port: 0,
+      fetch(req) {
+        const url = new URL(req.url)
+        if (!url.pathname.endsWith("/chat/completions")) {
+          return new Response("not found", { status: 404 })
+        }
+        return new Response(
+          hanging(() => ready.resolve()),
+          {
+            status: 200,
+            headers: { "Content-Type": "text/event-stream" },
+          },
+        )
+      },
+    })
+
+    try {
+      await using tmp = await tmpdir({
+        git: true,
+        init: async (dir) => {
+          await Bun.write(
+            path.join(dir, "opencode.json"),
+            JSON.stringify({
+              $schema: "https://opencode.ai/config.json",
+              enabled_providers: ["alibaba"],
+              provider: {
+                alibaba: {
+                  options: {
+                    apiKey: "test-key",
+                    baseURL: `${server.url.origin}/v1`,
+                  },
+                },
+              },
+              agent: {
+                build: {
+                  model: "alibaba/qwen-plus",
+                },
+              },
+            }),
+          )
+        },
+      })
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          const session = await Session.create({ title: "Prompt cancel regression" })
+          const run = SessionPrompt.prompt({
+            sessionID: session.id,
+            agent: "build",
+            parts: [{ type: "text", text: "Cancel me" }],
+          })
+
+          await ready.promise
+          await SessionPrompt.cancel(session.id)
+
+          const result = await Promise.race([
+            run,
+            new Promise<never>((_, reject) =>
+              setTimeout(() => reject(new Error("timed out waiting for cancel")), 1000),
+            ),
+          ])
+
+          expect(result.info.role).toBe("assistant")
+          if (result.info.role === "assistant") {
+            expect(result.info.error?.name).toBe("MessageAbortedError")
+          }
+
+          const msgs = await Session.messages({ sessionID: session.id })
+          const last = msgs.findLast((msg) => msg.info.role === "assistant")
+          expect(last?.info.role).toBe("assistant")
+          if (last?.info.role === "assistant") {
+            expect(last.info.error?.name).toBe("MessageAbortedError")
+          }
+        },
+      })
+    } finally {
+      server.stop(true)
+    }
+  })
+})
+
 describe("session.prompt agent variant", () => {
   test("applies agent variant only when using agent model", async () => {
     const prev = process.env.OPENAI_API_KEY

packages/opencode/test/session/retry.test.ts

@@ -2,9 +2,14 @@ import { describe, expect, test } from "bun:test"
 import type { NamedError } from "@opencode-ai/util/error"
 import { APICallError } from "ai"
 import { setTimeout as sleep } from "node:timers/promises"
+import { Effect, Schedule } from "effect"
 import { SessionRetry } from "../../src/session/retry"
 import { MessageV2 } from "../../src/session/message-v2"
 import { ProviderID } from "../../src/provider/schema"
+import { SessionID } from "../../src/session/schema"
+import { SessionStatus } from "../../src/session/status"
+import { Instance } from "../../src/project/instance"
+import { tmpdir } from "../fixture/fixture"
 
 const providerID = ProviderID.make("test")
 
@@ -69,24 +74,47 @@ describe("session.retry.delay", () => {
     expect(SessionRetry.delay(1, longError)).toBe(700000)
   })
 
-  test("sleep caps delay to max 32-bit signed integer to avoid TimeoutOverflowWarning", async () => {
-    const controller = new AbortController()
-
-    const warnings: string[] = []
-    const originalWarn = process.emitWarning
-    process.emitWarning = (warning: string | Error) => {
-      warnings.push(typeof warning === "string" ? warning : warning.message)
-    }
-
-    const promise = SessionRetry.sleep(2_560_914_000, controller.signal)
-    controller.abort()
-
-    try {
-      await promise
-    } catch {}
-
-    process.emitWarning = originalWarn
-    expect(warnings.some((w) => w.includes("TimeoutOverflowWarning"))).toBe(false)
+  test("caps oversized header delays to the runtime timer limit", () => {
+    const error = apiError({ "retry-after-ms": "999999999999" })
+    expect(SessionRetry.delay(1, error)).toBe(SessionRetry.RETRY_MAX_DELAY)
+  })
+
+  test("policy updates retry status and increments attempts", async () => {
+    await using tmp = await tmpdir()
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const sessionID = SessionID.make("session-retry-test")
+        const error = apiError({ "retry-after-ms": "0" })
+
+        await Effect.runPromise(
+          Effect.gen(function* () {
+            const step = yield* Schedule.toStepWithMetadata(
+              SessionRetry.policy({
+                parse: (err) => err as MessageV2.APIError,
+                set: (info) =>
+                  Effect.promise(() =>
+                    SessionStatus.set(sessionID, {
+                      type: "retry",
+                      attempt: info.attempt,
+                      message: info.message,
+                      next: info.next,
+                    }),
+                  ),
+              }),
+            )
+            yield* step(error)
+            yield* step(error)
+          }),
+        )
+
+        expect(await SessionStatus.get(sessionID)).toMatchObject({
+          type: "retry",
+          attempt: 2,
+          message: "boom",
+        })
+      },
+    })
   })
 })
 
@@ -101,9 +129,9 @@ describe("session.retry.retryable", () => {
     expect(SessionRetry.retryable(error)).toBe("Provider is overloaded")
   })
 
-  test("handles json messages without code", () => {
+  test("does not retry unknown json messages", () => {
     const error = wrap(JSON.stringify({ error: { message: "no_kv_space" } }))
-    expect(SessionRetry.retryable(error)).toBe(`{"error":{"message":"no_kv_space"}}`)
+    expect(SessionRetry.retryable(error)).toBeUndefined()
   })
 
   test("does not throw on numeric error codes", () => {