[johnnyeric]

Staging queued usage writes currently traverse a private Frankfurt relay before reaching the Vercel writer. Remove the staging USAGE_WRITER_RELAY binding so the existing writer client calls the same https://staging-app.kilo.ai/api/internal/usage/record endpoint directly for a controlled latency comparison.

Keep the single EU source/DLQ, batch 2, parallelism 2, cap 200 (at most 400 writer calls), retry policy and diagnostics unchanged. Production effective configuration is identical. Retain relay code/config/tests and its deployed resource; revert this change and redeploy staging to restore the binding. Both existing CI paths skip relay deployment when unbound and retain EU preparation/consumer uploads.

Validation: 157 service tests across 12 files, 17 queue-preparation tests, nine deployment-workflow tests; typecheck, lint, generated types check, formatting and diff check; local staging/production dry runs. Actual local workerd/Queue/loopback HTTP tests cover the normal direct route and explicitly bound relay route, including ACK/retry behavior. Actual config checks prove production equality and both CI detection outputs. No hosted deployment, measurements or latency improvement claimed.

AISAGE-781

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Assumptions: [INFERENCE] Tests were not executed in this read-only sandbox (dependencies are not installed); test-harness behavior was reviewed from source only.

Files Reviewed (9 files)

• services/usage-ingest/README.md
• services/usage-ingest/diagnostics.md
• services/usage-ingest/eu-queues.md
• services/usage-ingest/src/consume-usage.runtime.test.ts
• services/usage-ingest/src/index.runtime.test.ts
• services/usage-ingest/src/publish-usage.ts
• services/usage-ingest/src/writer-relay.runtime.test.ts
• services/usage-ingest/worker-configuration.d.ts
• services/usage-ingest/wrangler.jsonc

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_{Reviewed by deepseek-flash-latest · Input: 75.6K · Output: 15.1K · Cached: 1.6M}

_{Review guidance: REVIEW.md from base branch main}