kandev/docs/plans/diagnostic-logging/task-02-frontend-error-endpoint.md

id, title, status, wave, depends_on, plan, spec

id	title	status	wave	depends_on	plan	spec
02-frontend-error-endpoint	Frontend-error endpoint	completed	2	01-backend-log-sinks	plan.md	../../specs/platform/requirements/diagnostic-logging.md

Task 02: Frontend-error endpoint

Acceptance

• Authenticated install users can submit the exact bounded POST /api/v1/system/logs/frontend-errors contract and receive 204.
• A valid request creates one fixed frontend error toast error entry with client data, including an optional bounded task_id, only in structured fields.
• Malformed, oversized, source-invalid, text-empty, and truncation cases follow the spec without weakening the existing log-download allow-list.
• Per-identity 60/minute burst-20 and process-wide 300/minute burst-100 token buckets return 429 plus Retry-After; stale identity buckets are removed.
• The endpoint lives in internal/system/frontenderrors, not the legacy internal/system/logs package removed by Task 09.

Verification

cd apps/backend
go test ./internal/system/frontenderrors ./internal/system

Files likely touched

• apps/backend/internal/system/frontenderrors/handler.go
• apps/backend/internal/system/frontenderrors/handler_test.go
• apps/backend/internal/system/frontenderrors/limiter.go
• apps/backend/internal/system/frontenderrors/limiter_test.go
• apps/backend/internal/system/system.go
• apps/backend/internal/system/system_routes_test.go

Dependencies

• Task 01 provides the dual-sink logger and fixed file used by the endpoint.

Parallelism

Parallel-safe with Task 03 after Task 01. The files are disjoint from the launcher implementations and no shared schema or generated contract changes.

Inputs

• Spec: API surface, Permissions, Failure modes, and report Scenarios.
• Plan: Backend / Frontend-error ingestion.
• Existing patterns: System route composition and system/logs handler tests.

Risks

• Body limiting must occur before JSON decoding.
• Truncation must preserve valid UTF-8 and must not turn client data into a log message or level.
• task_id is an untrusted correlation field, not authorization or proof that the reporting user owns a task.
• Limiter identity keys come only from authenticated context; task IDs and browser fields never select a bucket.

Output contract

Report the final request shape and limits, files changed, exact test command/result, blockers or risks, and update this task plus plan.md status in the same conversation.