kandev/docs/plans/cursor-retriable-stream-reset/task-02-classify-cursor-stream-resets.md

id, title, status, wave, depends_on, plan, requirements, acceptance_criteria, system_design

id	title	status	wave	depends_on	plan	requirements	acceptance_criteria	system_design
02-classify-cursor-stream-resets	Classify Cursor stream resets	done	1		plan.md	REQ-PLATFORM-PROVIDER-ERROR-RECOVERY-001	AC-PLATFORM-PROVIDER-ERROR-RECOVERY-001.14	../../specs/platform/system-design/provider-error-recovery.md

Task 02: Classify Cursor Stream Resets

Summary

Add a dedicated deterministic fingerprint for Cursor's safe stream-reset diagnostic and map it to the existing transient transport-loss cause. Preserve the generic transport matcher and the context-cancellation safety veto.

In scope

• Dedicated runtime rule and stable classifier rule ID.
• Exact positive, prose and partial negatives, and collision tests.
• Full classification invariants and transient helper coverage.
• Explicit [canceled] non-veto coverage.

Out of scope

• ACP event detection or suppression.
• Retry scheduling or effect-safety changes.
• Widening transportLostRe.

Acceptance

• The stable emitted diagnostic classifies as high-confidence CodeAgentTransportLost with class ClassTransient and AutoRetryable=true.
• The rule does not match prose or incomplete transport tokens and does not change the priority of more specific existing rules.
• [canceled] remains distinct from context cancellation, while existing context-cancelled composite envelopes remain non-retryable.

Verification

cd apps/backend && go test -race ./internal/agent/runtime/routingerr -run 'Test(ClassifyCursorRetriable|MatchRuntimeEnvironmentRules_CursorRetriable|IsTransientProviderError_Cursor)'

Files likely touched

• apps/backend/internal/agent/runtime/routingerr/runtime_rules.go
• apps/backend/internal/agent/runtime/routingerr/cursor_retriable_stream_reset_test.go

Dependencies

None.

Risks

• An overly broad expression can classify user-authored prose or unrelated cancellation output as transport loss.
• Rule ordering can accidentally supersede overload or resume-corruption fingerprints.

Parallelism

parallel-safe with Task 01. The files are disjoint.

Inputs

• Provider Error Recovery criterion .14.
• Cursor classification section in the system design.
• Existing transport-loss rule and tests.

Results

• Added cursor.retriable_stream_reset.v1 with complete normalized-diagnostic matching and the existing cancellation veto.
• Verification passed: cd apps/backend && go test -race ./internal/agent/runtime/routingerr -run 'Test(ClassifyCursorRetriable|MatchRuntimeEnvironmentRules_CursorRetriable|IsTransientProviderError_Cursor)'.