docs · adapters
Hermes Agent#
Unreleased: after 0.11.0. This page is on Hekma's main branch and ships in the next release; Hekma 0.11.0 does not have it.
Hermes Agent (NousResearch) speaks the Agent Client Protocol natively through its hermes-acp entry point, so it runs under Hekma's built-in acp kind with no adapter work of its own — and it is the one gallery entry whose billing-grade metering tier yields out of the box.
Register#
hekma agent config set my-hermes acp.command "hermes-acp"
hekma agent register my-hermes --kind acp
hekma agent start my-hermesNo acp.args are needed. The deprecated hermes kind targets the same agent through a fixed gateway launch; new registrations should use --kind acp — see built-in kinds for the migration parity (metering and memory delivery both carry over).
Honesty table#
The pause and interaction levels are the acp kind's own capability declaration — identical for every ACP agent and proven by the conformance kit against a scripted stand-in; they are not per-agent promises. The metering rows are what the pinned real-agent run demonstrated.
| Surface | Value | Evidence class |
|---|---|---|
pause | guaranteed (Linux), guaranteed (macOS), best-effort (Windows) | contract-validated |
interaction | guaranteed (all OSes) | contract-validated |
| Metering source | self-reported | run-verified |
| Billing-grade tokens | the self-reported sentinel rides the agent's stderr (KTESIO_USAGE {json} lines, cached tokens included) — the only gallery entry whose sentinel tier yields | run-verified |
| Context usage | the agent's usage_update surfaces under acp_context_usage — context-grain, never billed | run-verified |
Validation status. Upstream: stable. Evidence: run-verified — registered, started (handshake and session), one full prompt turn completed with the reply retained, metered context-grain, stopped clean. Validated against v0.21.7+500.g8f81791 (2026-10-16); the pin is also recorded in Supported agents.
PATH requirement#
The launch command is the bare word hermes-acp, resolved through the PATH of the environment hekma runs in. Hekma does not bundle, install or pin the Hermes binary — install it yourself, keep it on the PATH, or give an absolute path. A start whose hermes-acp cannot resolve fails with the engine's launch-failure diagnostic naming the executable.
Re-validation duty#
Hermes merges near-daily; the pin above is a snapshot by design. Re-validate against the version you install before relying on agent-specific behaviour, and move the pin forward with fresh evidence — Re-validation states the full duty, including the contract duties that no automated kit can prove.
Read next#
- Adapter Gallery: the index this entry belongs to.
- Run an ACP agent: the Hermes recipe, prompts and session handling.
- Supported agents: the validation pins and the duty in full.