graphban-fleet

The fleet supervisor: a thin local client that runs where the agents actually run. It spawns vendor CLI processes holding seats the Graphban server issued, and it reaps them. Ships as graphban-fleet, with a gbfleet entry point.

Specified by PRD-22.

Two servers, and only one of them has authority

Arbitration is remote and authoritative; process control is local and unprivileged. A planner attaches both:

planner (a terminal, or an in-session orchestrator)
 ├─ graphban   (remote HTTP)  → mint_enrolment, propose_allocation, assign_role, fleet_status
 └─ gbfleet    (local stdio)  → spawn, stop, ps, orphans

gbfleet runs on the developer's machine and the Graphban server never learns its calls happened. There are no HTTP routes on the local surface. Authentication there is process ownership — the planner speaks over a pipe to a child it launched — not a credential.

The supervisor holds no authority of its own. It can only launch a process holding a seat the server issued, to do work the server arbitrates. Delete it and every invariant still holds; the fleet just needs a human to open terminals again. It is explicitly not a security boundary (PRD-22 D-k): a compromised vendor binary has whatever the user has, and the worktree is a blast-radius convention, not a sandbox.

Why it is in this repository, and not inside backend/

Not a second repository, because the client↔server contract has no schema anywhere — the enrolment code format and its TTL, register_agent's return shape, independent()'s seat semantics, the directive envelope. All of it is changeable in a single PR here, and a cross-repo break would present as absence reading clean: the fleet still spawns, nothing errors, review stops being independent.

Not inside backend/, because graphban-api pulls fastapi, sqlalchemy, pgvector, psycopg, alembic, redis and cryptography, and a laptop running four vendor CLIs needs none of them. tests/test_packaging.py derives its forbidden-dependency set from the backend's own list, so that separation is checked rather than asserted.

Licence — Apache-2.0, deliberately not the repository's FSL-1.1

The repository is FSL-1.1-Apache-2.0. This directory is Apache-2.0, and the divergence is a decision (PRD-22 §8), not an oversight:

• The supervisor is not the moat. It is inert without a Graphban server and holds no authority. FSL's Competing Use clause protects the server; it protects nothing here.
• Adapters are the contribution this component most wants, and they come from people who use other vendors' tools. A non-OSI licence is friction aimed at exactly that audience.
• It is a laptop-installed developer CLI, which is precisely the kind of dependency that meets a corporate licence policy scanner.
• FSL-1.1-Apache-2.0 already commits to Apache-2.0 on a two-year delay. This brings that grant forward for the one component least worth protecting.

If this component is ever extracted to its own repository — the stated trigger is outside contributors who should not hold commit access to the server — extract the adapter interface only, not the supervisor.

Install

Not on PyPI yet, so it installs from the repository:

uv tool install "git+https://github.com/asc-me/graphban.git#subdirectory=fleet"

That gives you gbfleet and gbagent. uv tool update-shell once if uv says its bin directory is not on your PATH, and uv tool upgrade graphban-fleet to move it forward — the spec tracks a branch, so an upgrade is not automatic and a fix landing here does not reach a machine until somebody asks for it.

gban, the client for a human at a terminal, is a separate package — #subdirectory=cli — because it installs on laptops that never run a wave and must stay dependency-free.

Running it

One wave, deterministically — you mint the seats, it spawns and reaps:

GBFLEET_API_KEY=... gbfleet up \
    --server https://cloud.agentldgr.dev --seats-file seats.txt --adapter claude

A seats file is one enrolment code per line. A line may also bind the seat to an item (WORKER-7F3K item=GRPH-755 — the child gets the BOUND instruction and claims that item at registration, PRD-36) or name its role (REVIEWER-2Q9C role=reviewer — the child gets the reviewer instruction). Both are what until says when it mints a seat itself; here you say them. A mistyped token refuses the whole file before any worktree is cut, and doctor --seats-file refuses it the same way.

Or hand the local surface to a planner over stdio:

GBFLEET_API_KEY=... gbfleet mcp --server https://cloud.agentldgr.dev

spawn starts one child and takes no count. The planner decides how many to run — it holds both servers, so it can read collision_clusters and get_backlog itself, mint that many seats, and call spawn once each. The supervisor executes.

Delegate to a seat (PRD-36). A parent that wants one item built on a cheaper model does it in two calls and keeps working: delegate(id, lane, tier, seat=true) on the Graphban server mints a worker seat bound to the item and returns its code; then spawn(enrolment_code=<code>, tier="cheap", item=<id>) here. Registering on a bound seat claims the item server-side, so the child holds it from its first call and never touches claim_cluster; the spawn reply echoes the roster's assigned block (claimed, or taken with who holds it). tier resolves through a table the operator names at launch — gbfleet mcp --tier cheap=gbagent:qwen3.6:35b-a3b-coding-mtp-det --tier frontier=claude:opus — fixed for the life of the process, and an explicit adapter overrides it. gbfleet until takes the same --tier table plus --request cheap|frontier for what its own delegations ask, and mints bound seats for the seeds it delegates, so the divvy no longer decides what its children claim. The outcome comes back through the ledger — the item moving on the board — never as a reply in the parent's context.

The preference matrix (PRD-37). A tier with no --tier flag resolves through src/gbfleet/matrix.toml, a committed table of harness × model × lane × role × tier rows with a status (verified, unverified, failed, unregistered) and the item that proved it — facts only, reviewed like code. Resolution runs in a fixed order: the rows for the tier and role → the project's policy (local_only, allowed_harnesses, reviewer_cross_vendor) → the user's profile (an ordered allowlist of harnesses, weights over cost/quality/latency/locality, excludes) → failed rows out → what this machine has installed → score → ties (verified first, then the user's own order, then the row's order). Profile and policy come from the server: gbfleet mcp and gbfleet until read them off fleet_status once at launch (a change is read at the next launch, PRD-36 D16) — the profile is the API key owner's, with a per-project override, edited in the Fleet view under the Wave tab; the policy is the project's. A key whose owner has no profile, or a server that cannot be reached at launch, resolves on matrix order and policy alone and the explanation says profile: none. A reviewer spawn may pass builder_vendor so a project's reviewer_cross_vendor rule can drop the builder's vendor. Every spawned child is told, in the same sentence as its enrolment code, to register with capabilities={vendor, model?, tier} for what the supervisor actually launched (GRPH-732), so the ledger can attribute its outcome; only a NAMED model is declared, since a vendor default is unknowable from here. Measured quality and latency also ride on fleet_status (per declared vendor × model × lane × tier, with n); the resolver reads the cell for the lane being resolved, never a pooled one, and counts an axis only past n ≥ 5. The spawn reply carries resolution: source (flag or matrix), how many rows survived each step, what each step dropped and why, the winner with its per-axis numbers, and the runner-up. An empty resolution is a tool error naming the step that emptied it — there is no silent default. Measured axes need n ≥ 5 before they count and say unmeasured until then. --matrix PATH on mcp, until and doctor swaps the file; gbfleet doctor prints every row against this machine and what each role/tier would resolve to. The file is TOML, not the YAML the PRD first wrote, because gbfleet is httpx-thin by requirement and tomllib is standard library.

Name the project. A credential that spans several projects resolves a call that names none to its default project, and that is not where the seats were minted: the child registers on the seat's project (the server takes it from the seat), but the supervisor's roster read and the child's own reads land elsewhere — the child never appears on the roster the supervisor polls and reads a backlog that is not its own. gbfleet mcp, gbfleet until and gbfleet doctor take --project <id>, named on every call; doctor fails a multi-project key that gives none. The child learns its project from the registration reply and names it afterwards (GRPH-718, GRPH-719).

What a wave reports about itself. Beyond spawn and reap, up and until print three findings a reviewer otherwise has no way to see, all measured from the worktrees the supervisor already owns and none of them acted on:

• COLLIDED <path>: changed on <branch>, <branch> — two workers changed the same file. The failure the partition exists to prevent, observed rather than predicted: exact paths, no coverage rule, and true whether the touchpoints were wrong or the divvy was.
• UNDECLARED <branch>: changed N file(s) no touchpoint covers — the partition's INPUT was wrong. Compared against the declaration as it stood when work was handed out, which is the snapshot the divvy used. An item that declared nothing is not drift; its areas were predicted, which the board already marks.
• BEHIND <branch>: cut from a base N commit(s) behind origin/main — how much landed on the trunk while the child worked. Two agents can each be green on their own base and conflict on merge, and nothing else in the system can see it: the server has no git, the reviewer gets a branch with no indication of what its diff is against, and the child was cut from HEAD at spawn and never looked again. The trunk is fetched once per wave before measuring — a remote-tracking ref is only as fresh as its last fetch, and a check that skipped it would report every branch as current. BEHIND unmeasured: <reason> when it could not be asked, because that is not the same as nothing having moved.

Vendors and what each of them needs: docs/fleet-adapters.md.

Development

cd fleet
uv venv --python 3.12 .venv
uv pip install -e ".[dev]"
.venv/bin/python -m pytest -q

The suite fails loudly if the package is not installed, rather than testing an uninstalled fallback and passing.