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 instructions/cocaxcode/api-testing-mcp/claude-mdgit clone --depth 1 https://github.com/cocaxcode/api-testing-mcpWhat 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 | $0.00959 | $0.00959 |
| Opus 5 | $0.00479 | $0.00479 |
| Sonnet 5 | $0.00192 | $0.00192 |
| Haiku 4.5 | $0.00096 | $0.00096 |
Grade A, and why
api-testing-mcp CLAUDE.md 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.
How it starts
The opening of the file, as written. The whole thing — 82 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md — @cocaxcode/api-testing-mcp
Project Overview
MCP server for API testing. Zero cloud dependencies, local JSON storage. 42 tools, 171 tests.
Token-optimized responses (v0.13+)
request accepts three optional parameters that cut context tokens by 70-97%:
verbosity:'minimal' | 'normal' | 'full'(default'normal')only_fields:string[]with dot-paths (data.id,items[*].name)max_body_bytes: number (default 2048) for'normal'
Every compressed response includes a call_id. Use inspect_last_response({ call_id }) to recover the full unfiltered response when needed. Responses are cached in a 20-slot ring buffer + .api-testing/last-responses/ with 1h TTL.
Header filter lists live in lib/compress.ts (FILTERED_HEADERS, FILTERED_HEADER_PATTERNS).
Stack
- TypeScript 5.x (strict mode, ESM)
- @modelcontextprotocol/sdk 1.27.x (unified package)
- Zod 3.25+ for schema validation
- Vitest for testing (InMemoryTransport for integration tests)
- tsup for building (ESM output with shebang)
Architecture
src/
├── index.ts # Entry point (shebang + StdioServerTransport)
├── server.ts # createServer() factory
├── tools/ # MCP tool registration (one file per group)
│ ├── request.ts # HTTP request tool (1)
│ ├── collection.ts # Collection CRUD tools (4)
│ ├── environment.ts # Environment tools (10)
│ ├── api-spec.ts # OpenAPI import/browse tools (4)
│ ├── assert.ts # Assertion testing tool (1)
│ ├── flow.ts # Request chaining tool (1)
│ ├── mock.ts # Mock data generation tool (1)
│ ├── load-test.ts # Load testing tool (1)
│ └── utilities.ts # export_curl, diff_responses, bulk_test, export/import_collection, export/import_environment, export/import_postman_collection, export/import_postman_environment (11)
├── lib/ # Business logic (no MCP dependency)
│ ├── types.ts # Shared TypeScript interfaces
│ ├── schemas.ts # Shared Zod schemas (AuthSchema, HttpMethodSchema)
│ ├── url.ts # resolveUrl() — BASE_URL auto-prepend
│ ├── path.ts # getByPath() — dot notation accessor
│ ├── http-client.ts # fetch wrapper with timing
│ ├── storage.ts # JSON file storage in .api-testing/
│ ├── interpolation.ts # {{variable}} resolver
│ └── openapi-parser.ts # OpenAPI spec parser with $ref + allOf/oneOf/anyOf
└── __tests__/
├── helpers.ts # createTestClient() with InMemoryTransport
└── *.test.ts # 10 test files, 110 tests
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 · 82 lines · 959 tokens per session scan A 5f62c7ae06d8
api-testing-mcp CLAUDE.md is an instructions file published in the GitHub repository cocaxcode/api-testing-mcp (6 stars, last pushed 4mo ago), licensed MIT. It adds 959 tokens to every session, about $0.0048 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 2026-08-31.
Other instructions, from other repositories
shimwire CLAUDE.md
Instructions for caspel26/shimwire, covering shimwire, status, stack, gotchas and working conventions.
MCPstudio CLAUDE.md
Claude Code instructions for lonexreb/MCPstudio, covering claude.md — mcpstudio developer guide, project overview, quick start, backend and frontend.
llm-context.py CLAUDE.md
Instructions for cyberchitta/llm-context.py, covering claude.md, working notes (gitignored) and draining the field notes.
openrouter-mcp-multimodal AGENTS.md
Instructions for stabgan/openrouter-mcp-multimodal, covering agent instructions, before you ship, releasing (read this before publishing), short version and version files (must all match package.json).
seekstone CLAUDE.md
Instructions for shaqmughal/seekstone, covering claude.md, what this repo is, commands, the harness itself (run after npm install) and architecture.
Plonk AGENTS.md
Instructions for ostapondo/Plonk, covering agent rules, layout, adding a module, build & verify and code style.