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.
git clone --depth 1 https://github.com/aiagentwithdhruv/ai-dev-stackWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/rules/aiagentwithdhruv/ai-dev-stack/35-api-contracts)<a href="https://agentmods.dev/rules/aiagentwithdhruv/ai-dev-stack/35-api-contracts"><img src="https://agentmods.dev/badge/rules/aiagentwithdhruv/ai-dev-stack/35-api-contracts/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/rules/aiagentwithdhruv/ai-dev-stack/35-api-contracts"><img src="https://agentmods.dev/badge/rules/aiagentwithdhruv/ai-dev-stack/35-api-contracts.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What 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 5.1 | $0.00000 | $0.00281 |
| Opus 5.5 | $0.00000 | $0.00112 |
| Sonnet 5.5 | $0.00000 | $0.00056 |
| Haiku 4.5 | $0.00000 | $0.00028 |
Grade A, and why
35-api-contracts 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 1mo 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
API contract rules:
- Version APIs explicitly, e.g. /api/v1/, /api/v2/.
- Never introduce breaking changes to an existing version without deprecation.
- Document breaking vs non-breaking changes clearly.
- Use OpenAPI/Swagger specs when the project supports it.
Schema evolution:
- Add new fields as optional — never remove or rename existing fields in-place.
- Use explicit migration paths when changing response shapes.
- Dataset schema changes (JSONL, JSON) must be versioned alongside code.
- When training data format changes, document the version and conversion script.
Contract expectations:
- Request and response schemas must be typed (Pydantic, TypeScript interfaces).
- Error responses must follow a consistent structure across all endpoints.
- Pagination, filtering, and sorting must use consistent query parameter conventions.
- All public endpoints must have example request/response in docs or tests.
Deprecation process:
- Mark deprecated endpoints with headers or response metadata.
- Set a removal timeline and communicate it.
- Log usage of deprecated endpoints to track migration.
Do not:
- Ship breaking API changes without versioning.
- Return different response shapes from the same endpoint based on hidden logic.
- Leave undocumented endpoints in production.
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.
- 1mo ago First seen · 33 lines · 0 tokens per session scan A d3568664cdae
35-api-contracts is a cursor rule published in the GitHub repository aiagentwithdhruv/ai-dev-stack (11 stars, last pushed 3mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 281 tokens. 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 2026-08-31.
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