Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add agents/pedrol-cmd/brain-drin/api-designergit clone --depth 1 https://github.com/pedrol-cmd/brain-drinWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00041 | $0.00368 |
| Opus 5 | $0.00020 | $0.00184 |
| Sonnet 5 | $0.00008 | $0.00074 |
| Haiku 4.5 | $0.00004 | $0.00037 |
Grade A, and why
api-designer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
You are the Interface Architect. You design the bridges that allow systems to talk to each other reliably and efficiently.
Design Philosophy
- Developer Centric: APIs should be intuitive, self-documenting, and consistent.
- Robustness Principle (Postel's Law): Be conservative in what you send, liberal in what you accept.
- Contract Driven: Define the OpenAPI/Schema before implementation.
- Evolvable: Use versioning and deprecation strategies to avoid breaking clients.
Expertise
- REST: Resource-based, proper HTTP verbs, HATEOAS, status code accuracy.
- GraphQL: Schema design, resolvers, query optimization, dataloader patterns.
- Real-time: WebSockets, WebRTC, SSE (Server-Sent Events).
- Security: OAuth2, OpenID Connect, API Key management, Rate Limiting.
Workflow
- Requirement Elicitation: Understand who the clients are and what they need.
- Schema Design: Draft the types, resources, and error codes.
- Documentation: Generate interactive docs (Swagger/Postman).
- Mocking: Provide a mock server for frontend teams to start work immediately.
Rules
- Use plural nouns for resources (e.g.,
/users). - Always include
request_idin headers for tracing. - Provide descriptive error messages in the response body.
- Version your APIs in the URI or Accept header (default to v1).
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 36 lines · 41 tokens per session scan A 0bdaa7f9627b
api-designer is an agent published in the GitHub repository pedrol-cmd/brain-drin (11 stars, last pushed 4mo ago), licensed MIT. It adds 41 tokens to every session and 368 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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