Pre-release

This release is a pre-release and may not be stable for production use.

MCP Hangar

The policy enforcement plane for MCP -- deterministic admission and egress policy, attributable audit, and SIEM export for your MCP server fleet. MIT, self-hosted, no SaaS.

PyPI CI License: MIT

Why

In MCP, the tool list is a hint the client caches; the call path is the only surface a provider mediates in real time. Every governance primitive worth having -- revocation, per-tenant scoping, audit -- attaches there, or attaches to nothing. Hangar puts a policy enforcement plane on that seam: one mediated path for lifecycle, policy, and telemetry across your whole MCP server fleet.

Background: The Advisory List -- Why MCP Governance Lives at the Call Path

Install

pip install mcp-hangar
# or: uv pip install mcp-hangar

Quickstart

Point Hangar at an MCP server in config.yaml:

mcp_servers:
  github:
    mode: subprocess
    command: [uvx, mcp-server-github]
    env:
      GITHUB_TOKEN: ${GITHUB_TOKEN}

Then serve it:

mcp-hangar serve --config config.yaml                     # stdio (Claude Desktop)
mcp-hangar serve --config config.yaml --http --port 8000  # HTTP + REST API at /api/

The 1.5 server refuses to bind a non-loopback interface without auth. For a quick/insecure demo, pass --unsafe-no-auth; for anything real, configure the auth block.

Or skip the config entirely -- get filesystem, fetch, and memory servers wired into Claude Desktop in one line:

curl -sSL https://mcp-hangar.io/install.sh | bash && mcp-hangar init -y && mcp-hangar serve

What you get

  • Parallel tool calls -- one hangar_call fans out to many MCP servers concurrently; all results returned together.
  • Lifecycle management -- lazy start, health checks, single-flight cold starts, idle shutdown, and per-server circuit breaking.
  • Hot config reload -- add or withdraw servers and tools via file watch, no restart.
  • Per-tenant tool projection -- front-door mode presents a different executable surface per caller, fail-closed on unknown identity.
  • OAuth ingress -- advertise as an RFC 9728 protected resource and challenge external agents for verified tokens.
  • Auth & RBAC -- API-key and OIDC/JWT identity with role-based access; bootstrap the first administrator with mcp-hangar auth bootstrap-admin, and every call carries a verified principal into the audit trail.
  • Observability built in -- OpenTelemetry traces, Prometheus metrics, structured logs, and an event-sourced audit trail.

Configuring tools:

The per-server tools: key is overloaded and accepts two distinct forms:

  • A list of tool schemas is a pre-start visibility projection. It lets a tool be listed before its provider has started, so callers can see it up front. It is not an access policy. On start, the provider's dynamic tools/list is authoritative and replaces this projection entirely — a statically-listed tool that the provider does not return becomes uncallable and fails with Tool not found: <name> at invocation (a warning naming the unconfirmed tool is logged at start).

  • A dict with allow: / deny: is an access policy (glob-pattern, three-level merge) that filters which discovered tools are exposed.

mcp_servers:
  math:
    mode: subprocess
    command: [python, -m, examples.provider_math.server]
    tools:                     # list form: pre-start schema projection
      - name: add
        description: "Add two numbers"
        inputSchema: { type: object, properties: { a: { type: number } } }
  github:
    mode: subprocess
    command: [uvx, mcp-server-github]
    tools:                     # dict form: allow/deny access policy
      allow: [create_issue, list_issues]
      deny: [delete_repository]

Documentation

License

MIT

Project links

Data verified by PyPI on Jul 23, 2026
Data provided by the project maintainers, verified at the time the release was uploaded to PyPI.

Key dates

PyPI data
Data sourced directly from PyPI's database.
  • Released:
Newer release available (2.17.0)

1 maintainer

PyPI data
Data sourced directly from PyPI's database.
Avatar for mapyr from gravatar.com mapyr

Credits

Author: Marcin Pyrka

GitHub Statistics

Data verified by PyPI on Jul 23, 2026
The GitHub source repository was provided by the project maintainers and verified by PyPI at the time of upload. Stars, forks, and open issues/PRs are derived from that repository and have not been independently verified.

License

MIT License (MIT)

Requires

Python >=3.11

Provides Extra

containers dev full langfuse opentelemetry postgres

Tags

ai infrastructure llm mcp model-context-protocol

Classifiers

Report project as malware

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

mcp_hangar-2.0.0a2.tar.gz (1.5 MB view details)

Uploaded Source

Built Distribution

If you're not sure about the file name format, learn more about wheel file names.

mcp_hangar-2.0.0a2-py3-none-any.whl (872.8 kB view details)

Uploaded Python 3

File details

Details for the file mcp_hangar-2.0.0a2.tar.gz.

File metadata

  • Download URL: mcp_hangar-2.0.0a2.tar.gz
  • Upload date:
  • Size: 1.5 MB
  • Tags: Source
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/6.1.0 CPython/3.13.14

File hashes

Hashes for mcp_hangar-2.0.0a2.tar.gz
Algorithm Hash digest
SHA256 e85163fb3884a066d0b9223593546fdd4b13c5aadc4da9aecfea2ce5a762d3b4
MD5 2dd366b6422386e09678ca5fe6455591
BLAKE2b-256 b0a861456f9d8974f5f85328c10a2410bc30fd4ad368cfbef36eec5248eb0701

See more details on using hashes here.

Provenance

The following attestation bundles were made for mcp_hangar-2.0.0a2.tar.gz:

Publisher: release.yml on mcp-hangar/mcp-hangar

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file mcp_hangar-2.0.0a2-py3-none-any.whl.

File metadata

  • Download URL: mcp_hangar-2.0.0a2-py3-none-any.whl
  • Upload date:
  • Size: 872.8 kB
  • Tags: Python 3
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/6.1.0 CPython/3.13.14

File hashes

Hashes for mcp_hangar-2.0.0a2-py3-none-any.whl
Algorithm Hash digest
SHA256 54661b957ea4a6525b3dc547d6b13f322164637078a589f29a9452b117fad250
MD5 37047a0e147e057b2c9191c82747817e
BLAKE2b-256 0e3ed591633f03f1d935401238382b92e766b867f0799f702caeb499bb871b0e

See more details on using hashes here.

Provenance

The following attestation bundles were made for mcp_hangar-2.0.0a2-py3-none-any.whl:

Publisher: release.yml on mcp-hangar/mcp-hangar

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

2.17.0

2 files

2.16.0

2 files

2.15.0

2 files

2.14.1

2 files

2.14.0

2 files

2.13.1

2 files

2.13.0

2 files

2.12.0

2 files

2.11.0

2 files

2.10.1

2 files

2.10.0

2 files

2.9.0

2 files

2.8.0

2 files

2.7.0

2 files

2.6.0

2 files

2.5.3

2 files

2.5.2

2 files

2.5.1

2 files

2.5.0

2 files

Pre-release

2.5.0rc4

2 files

Pre-release

2.5.0rc3

2 files

Pre-release

2.5.0rc2

2 files

Pre-release

2.5.0rc1

2 files

2.4.0

2 files

2.3.0

2 files

2.2.1

2 files

2.2.0

2 files

2.1.1

2 files

2.1.0

2 files

2.0.1

2 files

2.0.0

2 files

Pre-release

2.0.0rc4

2 files

Pre-release

2.0.0rc3

2 files

Pre-release

2.0.0rc2

2 files

Pre-release

2.0.0rc1

2 files

This release
Pre-release

2.0.0a2 This release

2 files

Pre-release

2.0.0a1

2 files

1.6.3

2 files

1.6.2

2 files

1.6.1

2 files

1.6.0

2 files

1.5.1

2 files

1.5.0

2 files

1.4.0

2 files

1.3.0

2 files

1.2.3

2 files

1.2.2

2 files

1.2.1

2 files

1.2.0

2 files

1.1.0

2 files

1.0.3

2 files

1.0.2

2 files

1.0.1

2 files

1.0.0

2 files

0.12.0

2 files

0.11.0

2 files

0.9.0

2 files

0.8.0

2 files

0.6.7

2 files

0.6.3

2 files

0.6.2

2 files

0.6.1

2 files

0.6.0

2 files

0.5.0

2 files

0.4.0

2 files

0.3.1

2 files

0.2.3

2 files

0.2.1

2 files

0.2.0

2 files

0.1.4

2 files

0.1.3

2 files

0.1.2

2 files

0.1.1

2 files

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page