What is openapi-sync-mcp CLAUDE.md?

Project instructions for an MCP server that reads and compares OpenAPI specifications, documents describing an API's endpoints and data formats.

Use them to parse specifications, find schema dependencies, compare versions for breaking changes, check status, and generate code.

They explain the available tools and workflows for checking, comparing, and generating code from an API specification.

How jhlee0409/openapi-sync-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to jhlee0409/openapi-sync-mcp. 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/jhlee0409/openapi-sync-mcp/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/jhlee0409/openapi-sync-mcp

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/jhlee0409/openapi-sync-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/jhlee0409/openapi-sync-mcp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/jhlee0409/openapi-sync-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/jhlee0409/openapi-sync-mcp/claude-md/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/jhlee0409/openapi-sync-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/jhlee0409/openapi-sync-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 379 This file is loaded in full into every session.

When invoked 379 The same file — it is already loaded in full.

Security scan A 0 findings. 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	$0.00379	$0.00379
Opus 5.5	$0.00152	$0.00152
Sonnet 5.5	$0.00076	$0.00076
Haiku 4.5	$0.00038	$0.00038

Measured 2mo ago against content hash fd89f8656512, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

openapi-sync-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 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.

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.

CLAUDE.md · 77 lines

What it actually says

Claude Instructions for OpenAPI Sync MCP

This MCP server provides tools for working with OpenAPI specifications.

Available Tools

Tool	Description
`oas_parse`	Parse and validate OpenAPI spec with pagination
`oas_deps`	Find schema dependencies and impact
`oas_diff`	Compare two spec versions
`oas_status`	Check cached spec status
`oas_generate`	Generate code from spec

Common Workflows

1. Parse a spec

{
  "name": "oas_parse",
  "arguments": {
    "source": "https://api.example.com/openapi.json",
    "format": "summary"
  }
}

2. Find what uses a schema

{
  "name": "oas_deps",
  "arguments": {
    "source": "./openapi.json",
    "schema": "User",
    "direction": "downstream"
  }
}

3. Check for breaking changes

{
  "name": "oas_diff",
  "arguments": {
    "old_source": "./openapi-v1.json",
    "new_source": "./openapi-v2.json",
    "breaking_only": true
  }
}

Plugin Commands

This MCP is used with the OAS plugin which provides /oas:* commands:

/oas:init - Initialize project
/oas:sync - Sync code with spec
/oas:status - Check status
/oas:diff - Compare specs
/oas:check - Validate code

Development

# Build
cargo build --release

# Test
cargo test

# Run locally
./target/release/openapi-sync-mcp

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 · 77 lines · 379 tokens per session scan A fd89f8656512

Subscribe to this mod's changes

openapi-sync-mcp CLAUDE.md is an instructions file published in the GitHub repository jhlee0409/openapi-sync-mcp (2 stars, last pushed 9mo ago), licensed MIT. It adds 379 tokens to every session, about $0.0015 per session on Opus 5.5. 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.

Backend and APIs LLM ai-tools api claude code-generator developer-tools

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openapi-sync-mcp: Instructions file for Claude Code