Capability Host Protocol — Docs
Reference

CLI reference

The chp command-line surface — host operations, agent hooks, sessions, version-control evidence, registry, and CI.

The chp CLI ships with chp-core. This page covers the developer-facing commands; run chp <group> --help for the full, authoritative surface.

pip install chp-core
chp --help

Host

chp host                       # print the running host descriptor
chp host verify                # smoke-test host + evidence store
chp serve-http --module <m>    # serve a host over HTTP
chp invoke <capability_id>     # invoke a capability (local or --url remote)
chp replay <correlation_id>    # replay evidence by correlation id

Hooks — capture agent tool calls

chp hooks install              # intercept Claude Code / Codex / Gemini tool calls
chp hooks status               # show which agent CLIs are hooked

Once installed, every tool call an agent makes is written to a local, SHA256-chained evidence store — no application code changes.

Sessions — inspect agent work

chp session list               # list recorded agent sessions
chp session tree <id>          # hierarchical event tree (parent + child agents)
chp session otel <id> --endpoint <url>   # export the trace to an OTLP collector

Work — version-control evidence

Governed development: gate commits and releases on evidence.

chp work check-alignment       # spec <-> schema <-> types alignment
chp work conformance-matrix    # protocol conformance checks
chp work vc precommit          # tests + alignment before commit
chp work vc release-bundle     # bundle evidence for a release
chp work vc merge-readiness    # final merge gate

Registry & policy

chp registry list              # list registered capabilities
chp policy lint                # validate a .chp/policy.json file

CI

chp ci check                   # evaluate policy against the session store
chp ci status                  # show recent CI runs

See the Python SDK for the programmatic API and the agent quickstart for the chp hooks workflow.

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