hyperhive/hive-subagent-mcp/README.md
atlas 34129d776c subagent: give each run its own signal URL, and drop the name argument
`goal_reached`/`need_help` took the session name as a tool argument, so
identity was an assertion by the caller and the only guard on it was
`occupancy()` — "does that name have a turn in flight", which two
concurrently running siblings both satisfy for each other. A subagent
could stop its sibling's run by naming it.

Identity moves into the URL. Each spawned run is minted an unguessable
token (`Uuid::new_v4`, the OS CSPRNG), the URL carrying it goes into that
one subagent's own `--mcp-config`, and the route resolves it back to a
session before dispatching to a handler bound to that session. Neither
tool takes a `name` any more: a subagent has no field in which to name a
sibling, and a sibling's name — which a brief may well mention — is not a
token.

One route with a path parameter, not a route per session: the `Router` is
built once at startup and subagents come and go for the daemon's whole
life. An unminted or revoked token gets a bare 404, the same answer either
way, so nothing enumerates. A run's token is revoked when the run ends
(`finish_turn`) or when a call never reached a spawn.

Two things fall out of that:

- the config file becomes one per session. A single shared path was
  already a race between two `start`s; with a per-session URL in it, the
  loser would read the winner's identity.
- `occupancy()` stops being the identity guard and is gone from the signal
  path entirely rather than kept "just in case" — a revoked token can't
  reach it, and it never answered the question it was standing in for.
  It still backs `status`, which is what it was always actually for.

Refs #4403
Refs #4413
2026-09-14 22:24:51 +02:00

1.8 KiB

hive-subagent-mcp

Per-agent daemon (hive-subagent-daemon) that spawns nested headless claude sessions on request and serves the tool surface (start/continue/status/interrupt, plus a separate subagent-facing goal_reached/need_help route, one per-session URL) directly over streamable-http. No stdio bridge, no per-turn respawn — an agent's claude reconnects to the same stable URL every turn.

Independent of hive-bash-mcp — a subagent spawns a full nested claude session, a much heavier capability than a bash command, worth its own deployable/restartable unit.

Shape

One bin (hive-subagent-daemon, src/main.rs) built from the crate's own lib (src/lib.rs):

  • session.rs — the actual claude-facing logic: Claude::spawn + RunningClaude::wait/cancel_handle (not InfiniteSession::run, which has no cancel handle to reach in — see the module doc for the v1 scope this trades away), the turn-continuation loop a goal switches on, and the in-memory maps that are the only state this daemon keeps (no task files — a restart stops whatever's running; the actual claude session is the durable store, found again by name via hive_claude::SessionStore).
  • mcp.rs — the rmcp tool routers (the parent's start/continue/status/interrupt on /mcp, the subagent's goal_reached/need_help on /signal/mcp/<token>) + serve_http. Neither signal tool takes a session name: the token in the path is minted per run and resolved to a session before dispatch, so a subagent has no way to name — and therefore no way to signal — a sibling. One route with a path parameter, because the Router is built once at startup and sessions come and go for the daemon's whole life.
  • paths.rs — the in-agent todo-socket path.