plugins/platforms/a2a/plugin.yaml

name: a2a-platform
label: A2A
kind: platform
version: 1.0.0
description: >
  A2A (Agent-to-Agent) protocol v1.0 support for Hermes Agent — both directions
  of the open Linux Foundation standard for inter-agent communication.

  OUTBOUND (client tools): a2a_discover, a2a_call, a2a_list, a2a_history, and
  a2a_orchestrate let the agent fetch another agent's Agent Card and send it
  tasks over JSON-RPC — works with any A2A-compliant peer (Hermes, LangChain,
  CrewAI, Google ADK, OpenClaw, ...).

  INBOUND (platform adapter): exposes Hermes as an A2A-discoverable agent. An
  Agent Card is served at /.well-known/agent-card.json (v1.0 canonical path;
  legacy agent.json also answers) and incoming tasks are routed
  into the agent's live gateway session like any other platform — so the agent
  that replies is the same one talking to its user, with full memory and
  context, not a throwaway clone.

  Security is on by default: no bearer token configured => localhost-only bind.
  Inbound task text passes through prompt-injection filters; outbound text is
  scrubbed of credential-shaped strings; every exchange is audit-logged and
  persisted to disk outside the context-compaction pipeline so conversations
  survive compaction and restarts.

  Pure stdlib transport (http.server + urllib) — no a2a-sdk dependency required.
author: Nous Research
# The outbound client tools. Declaring them here is what asks discovery to
# import `tools.py` in CLI/TUI processes, where the plugin is otherwise
# deferred and the tools would never register at all (#78050). The inbound
# adapter stays deferred either way — only this submodule is imported.
provides_tools:
  - a2a_discover
  - a2a_call
  - a2a_list
  - a2a_history
  - a2a_orchestrate
# requires_env / optional_env are surfaced in the `hermes config` UI via the
# platform-plugin env var injector in hermes_cli/config.py.
requires_env: []
optional_env:
  - name: A2A_PEER_TOKENS
    description: "Per-peer bearer tokens ('alice:tok1,bob:tok2'). Each remote agent gets its own credential; the matched name is the authenticated identity used for rate limiting, trust, and audit."
    prompt: "A2A per-peer tokens (name:token, comma-separated; or empty)"
    password: true
  - name: A2A_BEARER_TOKEN
    description: "Shared bearer token for inbound A2A calls (identity falls back to caller IP). With no token of any kind => bind to 127.0.0.1 only (no remote access)."
    prompt: "A2A shared bearer token (or empty for localhost-only)"
    password: true
  - name: A2A_HOST
    description: "Inbound bind host. Defaults to 127.0.0.1; only widens to 0.0.0.0 when a bearer token is set AND you opt in here."
    prompt: "A2A bind host (default 127.0.0.1)"
    password: false
  - name: A2A_PORT
    description: "Inbound A2A server port (default 9900)."
    prompt: "A2A port (default 9900)"
    password: false
  - name: A2A_AGENT_NAME
    description: "Name advertised on this agent's Agent Card (default: hostname-derived)."
    prompt: "A2A agent name"
    password: false
  - name: A2A_ALLOW_ALL_USERS
    description: "Allow any authenticated A2A peer to reach the agent (dev only)."
    prompt: "Allow all A2A peers? (true/false)"
    password: false
  - name: A2A_HOME_CHANNEL
    description: "Task/context id used as the cron / notification delivery target for deliver=a2a."
    prompt: "A2A home channel (or empty)"
    password: false