What is openapi-mcp-ts CLAUDE.md?

Project instructions for openapi-mcp-ts, a tool that turns an API description into tools an AI assistant can call. OpenAPI and Postman are formats used to describe HTTP APIs; MCP is a standard for connecting assistants to tools.

Understanding and developing the bridge between REST APIs and AI assistants. It covers API specification parsing, authentication, filtering, rate-limit awareness, logging, and safe defaults such as disabling DELETE.

It explains the project's purpose, architecture, technology choices, and safety rules so work on the code follows the existing design.

How procoders/openapi-mcp-ts configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to procoders/openapi-mcp-ts. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/procoders/openapi-mcp-ts/master/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/procoders/openapi-mcp-ts

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/procoders/openapi-mcp-ts/claude-md/github.svg)](https://agentmods.dev/instructions/procoders/openapi-mcp-ts/claude-md)

Your own site

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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.

Your own site · 80×15

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Per session 1,151 This file is loaded in full into every session.

When invoked 1,151 The same file — it is already loaded in full.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

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	$0.01151	$0.01151
Opus 5.5	$0.00460	$0.00460
Sonnet 5.5	$0.00230	$0.00230
Haiku 4.5	$0.00115	$0.00115

Measured 2mo ago against content hash 3a5bc188dbb8, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

openapi-mcp-ts CLAUDE.md scanned grade A with 1 finding 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 2mo 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl http://localhost:8080/health

CLAUDE.md · 129 lines

How it starts

The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.

openapi-mcp-ts

Universal bridge between REST APIs and AI assistants via Model Context Protocol.

What It Does

Takes an OpenAPI spec or Postman Collection and exposes every endpoint as an MCP tool. Claude (or any MCP client) can then call your API directly — no custom code, no manual tool definitions.

Why It Exists

Zero friction — Point at a spec, get MCP tools
Format agnostic — OpenAPI 3.0/3.1, Postman v2.0/v2.1, auto-detected
Production ready — Auth, filtering, rate limiting awareness, structured logging
Safe defaults — DELETE disabled, tool count warnings, smart error messages

Tech Stack

Component	Technology
Runtime	Node.js 20+ (ESM)
Language	TypeScript (strict mode)
HTTP Server	Hono
MCP Protocol	@modelcontextprotocol/sdk
CLI	Commander
Validation	Zod
OpenAPI Parsing	@apidevtools/swagger-parser
Postman Parsing	postman-collection
Logging	Pino

Architecture

┌─────────────────┐     ┌──────────────┐     ┌─────────────────┐
│  OpenAPI/Postman │ ──▶ │   Converter  │ ──▶ │   MCP Tools     │
│      Spec        │     │  (parser.ts) │     │ (definitions)   │
└─────────────────┘     └──────────────┘     └────────┬────────┘
                                                       │
┌─────────────────┐     ┌──────────────┐              │
│   MCP Client    │ ◀── │  MCP Handler │ ◀────────────┘
│ (Claude, etc)   │     │  (Hono SSE)  │
└─────────────────┘     └──────┬───────┘
                               │
                        ┌──────▼───────┐     ┌─────────────────┐
                        │   Upstream   │ ──▶ │   Target API    │
                        │   Proxy      │     │                 │
                        └──────────────┘     └─────────────────┘

Project Structure

src/
├── index.ts           # Entry point, server startup
├── cli.ts             # CLI argument parsing (Commander)
├── config/
│   └── loader.ts      # Config from CLI/env/file, Zod validation
├── converter/
│   ├── parser.ts      # OpenAPI/Postman → internal format
│   ├── postman-parser.ts  # Postman Collection v2.x support
│   └── tool-filter.ts # Include/exclude patterns, warnings
├── mcp/
│   ├── handler.ts     # MCP protocol, tool execution
│   └── types.ts       # MCP tool definitions
├── server/
│   ├── routes.ts      # /health, /tools, /mcp endpoints
│   └── upstream.ts    # Proxy requests to target API
└── utils/
    └── logger.ts      # Pino logger setup

Read the full file on GitHub · 129 lines

Changes

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.

2mo ago First seen · 129 lines · 1,151 tokens per session scan A 3a5bc188dbb8

Subscribe to this mod's changes

openapi-mcp-ts CLAUDE.md is an instructions file published in the GitHub repository procoders/openapi-mcp-ts (0 stars, last pushed 10mo ago), licensed Apache-2.0. It adds 1,151 tokens to every session, about $0.0046 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Backend and APIs Building agents

openapi-mcp-ts CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
openapi-mcp-ts CLAUDE.mdprocoders/openapi-mcp-ts	Instructions file	0	10mo ago	Apache-2.0	A	1,151	Claude Code
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vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
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openapi-mcp-ts: Instructions file for Claude Code