Generate and serve an OpenAPI 3.1 spec for the billing, usage, and developer routes

[greatest0fallt1me]

Description

The API is documented only via code comments and ad-hoc markdown; there is no machine-readable contract. This backend task introduces an OpenAPI 3.1 document covering /api/billing/deduct, /api/usage, /api/apis, and /api/developers/revenue, served at a /api/openapi.json route and validated in CI.

Requirements and Context

• Author an OpenAPI 3.1 spec describing request/response schemas and error shapes from src/errors/index.ts.
• Serve it from a new route mounted in src/routes/index.ts.
• Add a test that lints the spec and checks route coverage.
• Must be secure, tested, and documented
• Should be efficient and easy to review

Suggested Execution

1. Fork the repo and create a branch

   git checkout -b task/openapi-spec

2. Implement changes
   • docs/openapi.json (or generated) — the spec
   • src/routes/index.ts — serve /api/openapi.json
   • Add a spec validation test
3. Test and commit
   • npm test -- src/app.test.ts
   • Cover edge cases
   • Include test output and notes in the PR

Example commit message

task: add OpenAPI 3.1 spec for core routes

Acceptance Criteria

• /api/openapi.json returns a valid OpenAPI 3.1 document
• All four target routes are described with error responses
• A test fails if a documented route is missing or invalid

Guidelines

• Minimum 90% test coverage with Jest for the serving route
• Clear documentation and inline comments
• Timeframe: 96 hours

[drips-wave]

@greatest0fallt1me Bug-Hunter-X could not be assigned to this issue because they have reached the maximum of 4 accepted assignments per organization in the current wave of the Stellar Wave Program.

The assignee has been removed. Please choose a different contributor.

[emarc99]

@emarc99 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hy team! With familiarity/experience with the codebase, I'll like to fix this issue. ETA 1day!

ℹ️ Repo Maintainers: To accept this application, review their application or assign @emarc99 to this issue.

[drips-wave]

Congratulations, @emarc99! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @emarc99: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊