OpenAPI ProxyBLOCK
MCP server that dynamically exposes REST APIs defined by OpenAPI specs. Dual-stack MCP 1.x/2.x with native Streamable HTTP.
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
mcp-openapi-proxy is a Python package that implements a Model Context Protocol (MCP) server, designed to dynamically expose REST APIs—defined by OpenAPI specifications—as MCP tools. This facilitates seamless integration of OpenAPI-described APIs into MCP-based workflows.
2026-09-05 — 0.4.0: MCP 2.x / 2026-07-28 native Streamable HTTP (stateless POST /mcp, dual-stack with legacy stdio).
What's New in 0.4.0
MCP 2026-07-28 (SDK 2.x). The proxy is dual-stack: modern clients send self-contained requests (no initialize, no Mcp-Session-Id) and list results carry ttlMs / cacheScope. Legacy stdio clients that still handshake keep working. Native Streamable HTTP is available with MCP_TRANSPORT=streamable-http and is stateless — round-robin load balancing needs no sticky sessions.
See docs/MIGRATION-0.4.md for breaking changes, new env vars, and gateway cutover notes. 0.3.4 remains the last release on mcp 1.x (mcp>=1.2.0,<2).
What's New in 0.2.0
Works with every modern MCP-enabled client we tested. Strict MCP clients can now discover and call tools — the low-level server advertises correct capabilities and no longer crashes during resource/prompt discovery, and a slow spec download no longer crash-loops short-timeout clients. Verified live against the full list of mainstream agent CLIs:
- ✅ Codex, Gemini, Qwen, Kilocode, opencode — native tool calls over stdio
- ✅ Vibe — native discovery and read calls (writes were CLI-flaky, not a proxy issue)
- ✅ Letta — Cloud (via a remote streamable-HTTP MCP URL) and self-hosted (via stdio)
See the client matrix for attach mechanisms, models, and exact results.
📄 Full write-up: Verification case study — what the proxy is, the API + client matrices, and every defect found & fixed.
Prompts and resources are real now — including custom resources. Both MCP surfa
365fe2811065OBSERVED · 2026-10-07Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control. Replace the environment placeholders with a token scoped to the least it needs.
claude mcp add mcp-openapi-proxy --env API_AUTH_BEARER=${API_AUTH_BEARER} --env API_AUTH_HEADER=${API_AUTH_HEADER} --env API_AUTH_TYPE=${API_AUTH_TYPE} --env API_AUTH_TYPE_OVERRIDE=${API_AUTH_TYPE_OVERRIDE} -- uvx mcp-openapi-proxy{
"mcpServers": {
"mcp-openapi-proxy": {
"command": "uvx",
"args": [
"mcp-openapi-proxy"
],
"env": {
"API_AUTH_BEARER": "${API_AUTH_BEARER}",
"API_AUTH_HEADER": "${API_AUTH_HEADER}",
"API_AUTH_TYPE": "${API_AUTH_TYPE}",
"API_AUTH_TYPE_OVERRIDE": "${API_AUTH_TYPE_OVERRIDE}"
}
}
}
}Exposed tools (1)
1 read · 0 write · 0 destructive.
| Tool | Risk | Description |
|---|---|---|
get_test | read | Test tool |
Trust audit
BLOCKgrade D · trust 69/100 Do not install this without reading the findings. The audit found something that could harm you or your machine.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | FAIL |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | PASS |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- none-observed
- Network
- declared (5 observation(s))
- Shell
- declared (1 observation(s))
- Dependencies
- pinned
- Secrets in source
- found
Findings (22)
return yaml.load(content, Loader=_NoTimestampSafeLoader)
logger.debug(f"API_KEY: {api_key[:5] + '...' if api_key else '<not set>'}")logger.debug(f"API_KEY: {os.getenv('API_KEY', '<not set>')[:5] + '...' if os.getenv('API_KEY') else '<not set>'}")logger.debug(f"API_KEY: {os.getenv('API_KEY', '<not set>')[:5] + '...' if os.getenv('API_KEY') else '<not set>'}")"API_KEY": "xoxb-your-bot-token-here",
.flake8
importlib.import_module(mod)
env_key = f"OPENAPI_SPEC_URL_{hashlib.md5(test_name.encode()).hexdigest()[:8]}"print(f"DEBUG: API_KEY set to: {os.environ['API_KEY'][:5]}...")print(f"DEBUG: API_KEY set for proxy: {os.environ['API_KEY'][:5]}...")load_dotenv(dotenv_path=os.path.join(os.path.dirname(__file__), '../../.env'))
load_dotenv(dotenv_path=os.path.join(os.path.dirname(__file__), '../../.env'))
load_dotenv(dotenv_path=os.path.join(os.path.dirname(__file__), '../../.env'))
load_dotenv(dotenv_path=os.path.join(os.path.dirname(__file__), '../../.env'))
load_dotenv(dotenv_path=os.path.join(os.path.dirname(__file__), '../../.env'))
curl -X PUT http://127.0.0.1:8283/v1/tools/mcp/servers \
curl http://127.0.0.1:8283/v1/tools/mcp/servers/glama/tools
proxy_pass http://127.0.0.1:8765;
urls.append(f"http://127.0.0.1:{port}/mcp")env["OPENAPI_SPEC_URL"] = "http://127.0.0.1:18931/slow.json"
verify=False
- `HA_TOKEN` — a Home Assistant **long-lived access token** (Profile → Long-Lived Access Tokens), passed via `API_KEY`; the proxy sends it as `Authorization: Bearer <token>` (its default scheme), so n
Gates applied: no_behavioural_pass.
365fe2811065full audit observations/trust-audit/mcp-server/matthewhand__openapi-proxy.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-07 | 365fe2811065 | BLOCK | D | 69 | first audit |
Questions
What is the OpenAPI Proxy MCP server?
MCP server that dynamically exposes REST APIs defined by OpenAPI specs. Dual-stack MCP 1.x/2.x with native Streamable HTTP.
What tools does OpenAPI Proxy expose?
1 in total: 1 read-only, 0 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.
Is OpenAPI Proxy safe to connect to an agent?
No — not without reading the findings first. The audit graded it D (69/100) and found 1 critical or high issue in the source. Each one is listed on this page with the file and line it is on.
What credentials does OpenAPI Proxy need?
It reads API_AUTH_BEARER, API_AUTH_HEADER, API_AUTH_TYPE, API_AUTH_TYPE_OVERRIDE, API_KEY, API_KEY_JMESPATH, ASANA_API_KEY, BOX_API_KEY, ELEVENLABS_API_KEY, FLY_API_KEY, GETZEP_API_KEY and MCP_REQUEST_STATE_KEY from the environment. Give it a token scoped to the least it needs — an agent that can be talked into calling a tool can be talked into calling it with your credentials.
How does OpenAPI Proxy run?
It speaks stdio and streamable-http, so it runs as a local process your client starts. It is published on PyPI as mcp-openapi-proxy.
How current is this page?
The grade is for one exact copy of the source (365fe2811065), read on 2026-10-07. The repository is watched and re-audited when it changes.