ahp-py

Python implementations of the Agent Host Protocol (AHP) — Microsoft's protocol for synchronized multi-client state over AI agent sessions. One repository, several independently installable packages:

Package	What it is
ahp-protocol	Wire types, pure state reducers and upstream's conformance corpora. The shared floor; no runtime dependencies.
ahp-host	The host: serves sessions to any AHP client (VS Code's Agent Sessions view, the Python client, the iOS app).
ahp-host-claude	Claude, via the Claude Agent SDK, as a host provider.
ahp-host-acp	Any Agent Client Protocol agent as a host provider.
ahp-client	The client.
ahp-gateway	One endpoint and one login in front of many hosts: an AHP host to clients, an AHP client to each node.

                 ahp-protocol
               ▲      ▲      ▲
               │      │      │
        ahp-host  ahp-gateway  ahp-client
          ▲                  (host + client)
          │
  ahp-host-claude, ahp-host-acp

The native iPhone and iPad client, Agent Host, lives in its own repository: ahp-client-ios. It speaks the same spec revision and lists the machines behind an ahp-gateway.

Install

Distributed from GitHub, not from a package index. ahp-protocol is the floor and installs first, because the others pin it and no index carries it:

pip install "ahp-protocol @ git+https://github.com/jackhumbert/ahp-py#subdirectory=packages/ahp-protocol"
pip install "ahp-host[ws] @ git+https://github.com/jackhumbert/ahp-py#subdirectory=packages/ahp-host"

Each package's README has its own install lines.

Develop

uv sync --all-packages --all-extras --all-groups
scripts/check.sh                  # the CI gate: lint, format, types, contracts, tests
scripts/check.sh ahp-host         # one package

Sibling dependencies resolve to the workspace ([tool.uv.sources] in the root pyproject.toml), so a change in ahp-protocol is what every other package tests against.

Each package's own README and AGENTS.md describe it; AGENTS.md covers the repository as a whole.