fix: escalating circuit breaker for doom loops in headless mode

packages/opencode/src/altimate/telemetry/index.ts

@@ -243,6 +243,9 @@ export namespace Telemetry {
  session_id: string
  tool_name: string
  repeat_count: number
+ // altimate_change start — escalation level for distinguishing ask/warn/stop in analytics
+ escalation_level?: number
+ // altimate_change end
  }
  | {
  type: "environment_census"

packages/opencode/src/session/processor.ts

@@ -27,6 +27,15 @@ export namespace SessionProcessor {
  // 30 catches pathological patterns while avoiding false positives for power users.
  const TOOL_REPEAT_THRESHOLD = 30
  // altimate_change end
+ // altimate_change start — escalating circuit breaker for doom loops
+ // When the repeat threshold is hit and auto-accepted (headless, config allow), the
+ // counter resets and the loop continues indefinitely. Escalation levels:
+ // 1st hit (30 calls): ask permission (existing behavior)
+ // 2nd hit (60 calls): ask + inject synthetic warning telling model to change approach
+ // 3rd hit (90 calls): force-stop the session — the model is stuck
+ const DOOM_LOOP_WARN_ESCALATION = 2 // hits before injecting warning
+ const DOOM_LOOP_STOP_ESCALATION = 3 // hits before force-stopping
+ // altimate_change end
  const log = Log.create({ service: "session.processor" })
 
  export type Info = Awaited<ReturnType<typeof create>>
@@ -42,6 +51,9 @@ export namespace SessionProcessor {
  // altimate_change start — per-tool call counter for varied-input loop detection
  const toolCallCounts: Record<string, number> = {}
  // altimate_change end
+ // altimate_change start — escalation counter: how many times each tool has hit TOOL_REPEAT_THRESHOLD
+ const toolLoopHits: Record<string, number> = {}
+ // altimate_change end
  let snapshot: string | undefined
  let blocked = false
  let attempt = 0
@@ -201,20 +213,77 @@ export namespace SessionProcessor {
  })
  }
 
- // altimate_change start — per-tool repeat counter (catches varied-input loops like todowrite 2,080x)
+ // altimate_change start — per-tool repeat counter with escalating circuit breaker
  // Counter is scoped to the processor lifetime (create() call), so it accumulates
  // across multiple process() invocations within a session. This is intentional:
  // cross-turn accumulation catches slow-burn loops that stay under the threshold
  // per-turn but add up over the session.
  toolCallCounts[value.toolName] = (toolCallCounts[value.toolName] ?? 0) + 1
  if (toolCallCounts[value.toolName] >= TOOL_REPEAT_THRESHOLD) {
+ toolLoopHits[value.toolName] = (toolLoopHits[value.toolName] ?? 0) + 1
+ const hits = toolLoopHits[value.toolName]
+ const totalCalls = hits * TOOL_REPEAT_THRESHOLD
+
  Telemetry.track({
  type: "doom_loop_detected",
  timestamp: Date.now(),
  session_id: input.sessionID,
  tool_name: value.toolName,
- repeat_count: toolCallCounts[value.toolName],
+ repeat_count: totalCalls,
+ escalation_level: hits,
  })
+
+ // Escalation level 3+: force-stop — the model is irretrievably stuck
+ if (hits >= DOOM_LOOP_STOP_ESCALATION) {
+ log.warn("doom loop circuit breaker: force-stopping session", {
+ tool: value.toolName,
+ totalCalls,
+ hits,
+ sessionID: input.sessionID,
+ })
+ await Session.updatePart({
+ id: PartID.ascending(),
+ messageID: input.assistantMessage.id,
+ sessionID: input.assistantMessage.sessionID,
+ type: "text",
+ synthetic: true,
+ text:
+ `⚠️ altimate-code: session stopped — \`${value.toolName}\` was called ${totalCalls} times, ` +
+ `indicating the agent is stuck in a loop. Please start a new session with a revised prompt.`,
+ time: { start: Date.now(), end: Date.now() },
+ })
+ blocked = true
+ toolCallCounts[value.toolName] = 0
+ toolLoopHits[value.toolName] = 0
+ break
+ }
+
+ // Escalation level 2: warn the model via synthetic message
+ if (hits >= DOOM_LOOP_WARN_ESCALATION) {
+ log.warn("doom loop escalation: injecting warning", {
+ tool: value.toolName,
+ totalCalls,
+ hits,
+ sessionID: input.sessionID,
+ })
+ await Session.updatePart({
+ id: PartID.ascending(),
+ messageID: input.assistantMessage.id,
+ sessionID: input.assistantMessage.sessionID,
+ type: "text",
+ synthetic: true,
+ text:
+ `⚠️ altimate-code: \`${value.toolName}\` has been called ${totalCalls} times this session. ` +
+ `You appear to be stuck in a loop. Stop repeating the same approach. ` +
+ `Either try a fundamentally different strategy or explain to the user what is blocking you. ` +
+ `The session will be force-stopped if this continues.`,
+ time: { start: Date.now(), end: Date.now() },
+ })
+ }
+
+ // Escalation level 1: ask permission (existing behavior)
+ // Reset before ask so denial/exception doesn't leave count at threshold
+ toolCallCounts[value.toolName] = 0
  const agent = await Agent.get(input.assistantMessage.agent)
  await PermissionNext.ask({
  permission: "doom_loop",
@@ -223,12 +292,11 @@ export namespace SessionProcessor {
  metadata: {
  tool: value.toolName,
  input: value.input,
- repeat_count: toolCallCounts[value.toolName],
+ repeat_count: totalCalls,
  },
  always: [value.toolName],
  ruleset: agent.permission,
  })
- toolCallCounts[value.toolName] = 0
  }
  // altimate_change end
  }
@@ -478,6 +546,9 @@ export namespace SessionProcessor {
  continue
  }
  if (needsCompaction) break
+ // altimate_change start — exit stream loop immediately on doom loop force-stop
+ if (blocked) break
+ // altimate_change end
  }
  } catch (e: any) {
  log.error("process", {