"""FastAPI app: the routes in design.md "API (controller)" plus /healthz and GET /swarms."""
from __future__ import annotations
import asyncio
import html
import os
import resource
import secrets
import threading
import time
import uuid
from collections import Counter
from collections.abc import Awaitable, Callable, Mapping
from contextlib import asynccontextmanager
from datetime import UTC, datetime
from typing import Annotated, Any
import httpx
from fastapi import APIRouter, Body, Depends, FastAPI, Header, HTTPException
from fastapi.responses import HTMLResponse, JSONResponse
from pydantic import Field, TypeAdapter
from starlette.background import BackgroundTask
from starlette.requests import Request
from flock.controller.preflight import run_preflight
from flock.controller.reconcile import agent_state, record_heartbeat, worker_state
from flock.controller.spawn import (
Refused,
SpawnAck,
SpawnRequest,
agent_depth,
agent_for_token,
agent_may,
remove_subtree,
set_token_key,
worker_cap_conflicts,
)
from flock.controller.spawn import spawn as spawn_child
from flock.controller.store import Row, Store, agent_tokens
from flock.models import (
AgentState,
AgentStatus,
BulkPromptAck,
BulkPromptRequest,
ChildrenPromptRequest,
Command,
CommandBatch,
EventBatch,
Harness,
PreflightReport,
PromptAck,
PromptCommand,
PromptRequest,
ProviderStatus,
SwarmSpec,
SwarmStatus,
TypeHealth,
TypeStatus,
WorkerHeartbeat,
WorkerState,
WorkerStatus,
)
MAX_WAIT = 30.0
ADMIT_GRACE = 10.0 # s, a heartbeat this soon after an admission may predate the prompt
SEEN_EVERY = 5.0 # s, min gap between last_seen writes per worker
_COMMAND = TypeAdapter(Annotated[Command, Field(discriminator="kind")])
def _now() -> datetime:
return datetime.now(UTC)
def _dt(ts: float | None) -> datetime | None:
return None if ts is None else datetime.fromtimestamp(ts, UTC)
class Notifier:
"""Wake-ups for long-polls. `notify` is safe to call from any thread."""
def __init__(self) -> None:
self._events: dict[str, asyncio.Event] = {}
self._loop: asyncio.AbstractEventLoop | None = None
def _fire(self, key: str) -> None:
ev = self._events.pop(key, None)
if ev is not None:
ev.set()
def notify(self, key: str) -> None:
loop = self._loop
if loop is None or loop.is_closed():
return
try:
same = asyncio.get_running_loop() is loop
except RuntimeError:
same = False
if same:
self._fire(key)
else:
loop.call_soon_threadsafe(self._fire, key)
async def wait(self, key: str, timeout: float) -> None:
self._loop = asyncio.get_running_loop()
ev = self._events.setdefault(key, asyncio.Event())
try:
await asyncio.wait_for(ev.wait(), timeout)
except TimeoutError:
pass
async def long_poll(self, key: str, check: Callable[[], Any], wait: float) -> Any:
"""Return check()'s first truthy result, or its last result after `wait` seconds."""
self._loop = asyncio.get_running_loop()
deadline = self._loop.time() + max(0.0, min(wait, MAX_WAIT))
while True:
ev = self._events.setdefault(key, asyncio.Event()) # grab before checking: no lost wake
result = check()
remaining = deadline - self._loop.time()
if result or remaining <= 0:
return result
try:
await asyncio.wait_for(ev.wait(), remaining)
except TimeoutError:
pass
class RequestStats:
"""Pure ASGI middleware counting requests per route template and status, with latency
(sum and max) and in-flight peak, for /healthz. Long-polls count their parked time."""
def __init__(self, app) -> None:
self.app = app
self.lock = threading.Lock()
self.routes: dict[str, dict[str, float]] = {}
self.statuses: Counter[str] = Counter()
self.in_flight = 0
self.peak_in_flight = 0
self.started = time.time()
async def __call__(self, scope, receive, send):
if scope["type"] != "http":
return await self.app(scope, receive, send)
status = {"code": 500}
async def send_wrapper(message):
if message["type"] == "http.response.start":
status["code"] = message["status"]
await send(message)
t0 = time.monotonic()
with self.lock:
self.in_flight += 1
self.peak_in_flight = max(self.peak_in_flight, self.in_flight)
try:
await self.app(scope, receive, send_wrapper)
finally:
dt = time.monotonic() - t0
route = scope.get("route")
key = f"{scope['method']} {getattr(route, 'path', 'unmatched')}"
with self.lock:
self.in_flight -= 1
r = self.routes.setdefault(key, {"n": 0, "sum_s": 0.0, "max_s": 0.0, "errors": 0})
r["n"] += 1
r["sum_s"] += dt
r["max_s"] = max(r["max_s"], dt)
if status["code"] >= 500:
r["errors"] += 1
self.statuses[f"{status['code'] // 100}xx"] += 1
def snapshot(self) -> dict:
with self.lock:
routes = {
k: {"n": int(v["n"]), "mean_s": round(v["sum_s"] / v["n"], 4),
"max_s": round(v["max_s"], 3), "5xx": int(v["errors"])}
for k, v in sorted(self.routes.items())
}
return {"since": self.started, "total": sum(self.statuses.values()),
"by_status": dict(self.statuses), "in_flight": self.in_flight,
"peak_in_flight": self.peak_in_flight, "routes": routes}
def process_stats() -> dict:
"""RSS and CPU seconds of the controller process (Spaces expose no metrics API)."""
try:
with open("/proc/self/statm") as f:
rss = int(f.read().split()[1]) * os.sysconf("SC_PAGE_SIZE")
except (OSError, ValueError, IndexError):
rss = 0
t = os.times()
return {"rss_mb": round(rss / 2**20, 1),
"max_rss_mb": round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss / 1024, 1),
"cpu_s": round(t.user + t.system, 2), "threads": threading.active_count(),
"time": round(time.time(), 1)}
# --------------------------------------------------------------------------- status builders
def agent_status(
a: Row,
w: Row | None,
spec: SwarmSpec | None,
pending: int,
now: float,
children: list[str] | None = None,
):
ts = spec.types.get(a["type"]) if spec else None
return AgentStatus(
name=a["name"],
swarm=a["swarm"],
type=a["type"],
harness=ts.harness if ts else Harness.claude,
model=ts.model if ts else "unknown",
provider=ts.provider_name if ts else None,
labels=ts.labels if ts else {},
state=agent_state(a, w, now),
idle_since=_dt(a["idle_since"]),
turn_id=a["turn_id"],
worker=a["worker"],
session_id=a["session_id"],
resumed=None if a["resumed"] is None else bool(a["resumed"]),
pending=pending,
tokens=agent_tokens(a),
cost_usd=a["cost"],
harness_estimate_usd=a["harness_estimate_usd"],
turns=a["turns"],
created_at=_dt(a["created_at"]),
last_heartbeat=_dt(a["last_heartbeat"]),
last_sync=_dt(a["last_sync"]),
msgboard_principal=a["msgboard_principal"],
parent=a["parent"],
children=children or [],
depth=agent_depth(spec, a),
)
def worker_status(w: Row, agents: list[str], now: float) -> WorkerStatus:
return WorkerStatus(
id=w["id"],
swarm=w["swarm"],
type=w["type"],
job_id=w["job_id"],
state=worker_state(w, now),
deadline=_dt(w["deadline"]),
agents=agents,
last_heartbeat=_dt(w["last_heartbeat"]),
launched_at=_dt(w["launched_at"] or w["created_at"]),
crashes=w["crashes"],
last_error=w.get("last_error"),
)
def swarm_status(store: Store, spec: SwarmSpec, now: float) -> SwarmStatus:
workers = {w["id"]: w for w in store.list_workers(spec.swarm)}
agents = store.list_agents(spec.swarm)
pending = store.pending_counts(spec.swarm)
types: dict[str, TypeStatus] = {}
for type_name in sorted(set(spec.types) | set(store.type_names(spec.swarm))):
ts = spec.types.get(type_name)
mine = [a for a in agents if a["type"] == type_name]
by_state = Counter(agent_state(a, workers.get(a["worker"]), now).value for a in mine)
w_state = Counter(
worker_state(w, now).value for w in workers.values() if w["type"] == type_name
)
types[type_name] = TypeStatus(
name=type_name,
health=TypeHealth(store.type_health(spec.swarm, type_name)),
replicas=ts.replicas if ts else 0,
agents_by_state=dict(by_state),
workers_by_state=dict(w_state),
cost_usd=round(sum(a["cost"] for a in mine), 6),
launch_error=store.launch_error(spec.swarm, type_name)[0],
)
providers: dict[str, ProviderStatus] = {}
for name, prov in spec.providers.items():
users = [t for t, ts in spec.types.items() if ts.provider_name == name]
providers[name] = ProviderStatus(
name=name,
type=prov.type,
self_hosted=prov.self_hosted,
types=users,
working=sum(types[t].agents_by_state.get("working", 0) for t in users if t in types),
max_working=prov.max_working,
zero_usage_agents=sum(
1 for a in agents if a["type"] in users and a["turns"] > 0
and not any(sum(u.model_dump().values()) for u in agent_tokens(a).values())),
)
return SwarmStatus(
swarm=spec.swarm,
namespace=spec.namespace,
bucket=spec.bucket,
types=types,
providers=providers,
agents_total=len(agents),
workers_total=len(workers),
pending_prompts=sum(pending.values()),
cost_usd=round(sum(t.cost_usd for t in types.values()), 6),
)
_AGENT_STATE_TONE = {
"working": "good",
"idle": "neutral",
"stuck": "warn",
"unknown": "serious",
"dead": "crit",
}
_WORKER_STATE_TONE = {
"launching": "accent",
"running": "good",
"draining": "warn",
"unknown": "serious",
"dead": "crit",
}
_STATE_ORDER = ["working", "idle", "stuck", "unknown", "dead", "launching", "running", "draining"]
_PAGE_CSS = """
:root{--bg:#fcfcfb;--card:#ffffff;--ink:#1b1b1a;--ink2:#5c5b57;--ink3:#8a8984;--line:#e6e5e1;
--accent:#2f6fde;--good:#0ca30c;--warn:#fab219;--serious:#ec835a;--crit:#d03b3b;--neutral:#9a9994;
--mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
--sans:system-ui,-apple-system,"Segoe UI",Roboto,Inter,sans-serif}
@media(prefers-color-scheme:dark){:root{--bg:#1a1a19;--card:#232321;--ink:#f1f0ec;--ink2:#b3b2ac;
--ink3:#85847f;--line:#34342f;--accent:#7ea6ff}}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.5 var(--sans)}
a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}
.wrap{max-width:1100px;margin:0 auto;padding:24px 16px 48px}
header{display:flex;flex-wrap:wrap;align-items:baseline;gap:8px 16px;margin-bottom:24px}
header h1{font-size:18px;font-weight:650;letter-spacing:-.01em;margin:0}
header .meta{color:var(--ink3);font-size:13px;margin-left:auto}
.swarm{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:20px;margin-bottom:20px}
.swarm h2{font-size:17px;font-weight:650;margin:0;letter-spacing:-.01em}
.kicker{color:var(--ink3);font-size:12px;text-transform:uppercase;letter-spacing:.06em}
.head{display:flex;flex-wrap:wrap;align-items:center;gap:8px 12px}
.sub{color:var(--ink2);font-size:13px;margin:4px 0 16px;word-break:break-all}
.sub code{font-family:var(--mono);font-size:12px;color:var(--ink2)}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:12px;margin-bottom:18px}
.stat{border:1px solid var(--line);border-radius:10px;padding:12px 14px;background:var(--bg)}
.stat .v{font-size:26px;font-weight:600;line-height:1.1;letter-spacing:-.02em}
.stat .l{color:var(--ink2);font-size:12.5px;margin-top:4px}
.tbl{overflow-x:auto}
table{border-collapse:collapse;width:100%;font-size:14px}
th{text-align:left;color:var(--ink3);font-weight:500;font-size:12px;text-transform:uppercase;
letter-spacing:.04em;padding:6px 10px;border-bottom:1px solid var(--line)}
td{padding:9px 10px;border-bottom:1px solid var(--line);vertical-align:top}
tr:last-child td{border-bottom:0}
td.num{font-variant-numeric:tabular-nums;text-align:right;white-space:nowrap}th.num{text-align:right}
td.name{font-weight:600}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chip{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);border-radius:999px;
padding:1px 9px 1px 7px;font-size:12.5px;color:var(--ink2);background:var(--bg);white-space:nowrap}
.chip b{color:var(--ink);font-weight:600;font-variant-numeric:tabular-nums}
.chip i,.badge i{width:8px;height:8px;border-radius:50%;background:var(--neutral);display:inline-block}
.good i{background:var(--good)}.warn i{background:var(--warn)}.serious i{background:var(--serious)}
.crit i{background:var(--crit)}.accent i{background:var(--accent)}
.badge{display:inline-flex;align-items:center;gap:6px;font-size:12.5px;font-weight:600;
border-radius:999px;padding:1px 9px 1px 7px;border:1px solid var(--line)}
.badge.crit{color:var(--crit);border-color:var(--crit)}
.badge.warn{color:var(--ink);border-color:var(--warn)}
details{margin-top:12px;border-top:1px solid var(--line);padding-top:10px}
summary{cursor:pointer;color:var(--ink2);font-size:13px;user-select:none}
summary:hover{color:var(--ink)}
.agents{display:flex;flex-wrap:wrap;gap:6px;margin-top:10px}
.agents a{font-family:var(--mono);font-size:12px;border:1px solid var(--line);border-radius:6px;
padding:2px 7px;color:var(--ink2);background:var(--bg)}
.agents a:hover{color:var(--accent);border-color:var(--accent);text-decoration:none}
.more{color:var(--ink3);font-size:12px;align-self:center}
.empty{border:1px dashed var(--line);border-radius:12px;padding:40px 20px;text-align:center;color:var(--ink2)}
.empty code{font-family:var(--mono);font-size:13px;color:var(--ink)}
footer{color:var(--ink3);font-size:12px;margin-top:24px}
"""
def _fmt_count(n: int) -> str:
if n >= 1_000_000:
return f"{n / 1_000_000:.1f}M"
if n >= 10_000:
return f"{n / 1_000:.1f}K"
return f"{n:,}"
def _chips(counts: dict[str, int], tones: dict[str, str]) -> str:
e = html.escape
keys = sorted(counts, key=lambda s: (_STATE_ORDER.index(s) if s in _STATE_ORDER else 99, s))
chips = [
f'{e(s)} {counts[s]}'
for s in keys
if counts[s]
]
return (
f'
{"".join(chips)}
' if chips else 'none'
)
def _status_page(store: Store, now: float) -> str:
e = html.escape
parts = []
for sw in store.list_swarms():
spec: SwarmSpec = sw["spec"]
st = swarm_status(store, spec, now)
removing = 'removing' if sw["removing"] else ""
stats = [
(_fmt_count(st.agents_total), "agents"),
(_fmt_count(st.workers_total), "workers"),
(_fmt_count(st.pending_prompts), "pending prompts"),
(f"${st.cost_usd:,.2f}", "cost"),
]
tiles = "".join(
f'
{v}
{l}
'
for v, l in stats
)
rows = []
for t in st.types.values():
health = (
'ok'
if t.health.value == "ok"
else f'{e(t.health.value)}'
)
if t.launch_error:
health += f' {e(t.launch_error[:200])}'
ts = spec.types.get(t.name)
model = (
f"{e(ts.resolved_model.qualified)}"
if ts and ts.resolved_model
else (f"{e(ts.model)}" if ts else "")
)
rows.append(
f'
{e(t.name)}
{health}
{model}
'
f'
{t.replicas:,}
'
f"
{_chips(t.agents_by_state, _AGENT_STATE_TONE)}
"
f"
{_chips(t.workers_by_state, _WORKER_STATE_TONE)}
"
f'
${t.cost_usd:,.2f}
'
)
table = (
'
agent type
health
model
'
'
replicas
agents
workers
cost
'
f"
{''.join(rows)}
"
)
details = []
for type_name in st.types:
names = [a["name"] for a in store.list_agents(spec.swarm, type_name)]
links = "".join(f'{e(n)}' for n in names[:200])
more = (
f'and {len(names) - 200:,} more'
if len(names) > 200
else ""
)
details.append(
f"{e(type_name)} · {len(names):,} "
f"{'agent' if len(names) == 1 else 'agents'}"
f'
{links}{more}
'
)
provs = " · ".join(
f"{e(pv.name)} {e(pv.type)}{' self-hosted' if pv.self_hosted else ''}, "
f"working {pv.working}" + (f" / max {pv.max_working}" if pv.max_working else "")
+ (f", {pv.zero_usage_agents} agents report zero tokens (cost unknown)"
if pv.zero_usage_agents else "")
for pv in st.providers.values()
)
provs = f'
"
)
# --------------------------------------------------------------------------- app
def create_app(
store: Store,
token: str,
background: Callable[[Notifier], Awaitable[None]] | None = None,
clock: Callable[[], datetime] = _now,
stats: Callable[[], dict] | None = None,
secret_source: Mapping[str, str] | None = None,
preflight_transport: httpx.AsyncBaseTransport | None = None,
enforce_max_working: bool | None = None,
) -> FastAPI:
"""`secret_source` holds provider keys for preflight (default: the process environment,
where the Space puts its secrets); `preflight_transport` lets tests fake the providers.
`enforce_max_working` defaults to FLOCK_MAX_WORKING_ENFORCE (on unless "0")."""
secret_source = os.environ if secret_source is None else secret_source
if enforce_max_working is None:
enforce_max_working = os.environ.get("FLOCK_MAX_WORKING_ENFORCE", "1") != "0"
# Admission overlay (max_working): what the controller learned about an agent's turn since
# its last heartbeat. agent -> (state, when): "admitted" (handed a prompt to start a turn),
# "working" (turn_started seen) or "idle" (turn_ended / turn_interrupted / prompt_deferred
# seen). A heartbeat that reports the agent replaces it (see `heartbeat_seen`).
live: dict[str, tuple[str, float]] = {}
notifier = Notifier()
store.listener = lambda kind, key: notifier.notify(f"{kind}:{key}")
set_token_key(store, token)
@asynccontextmanager
async def lifespan(app: FastAPI):
notifier._loop = asyncio.get_running_loop()
task = asyncio.create_task(background(notifier)) if background else None
yield
if task:
task.cancel()
app = FastAPI(title="flock controller", lifespan=lifespan)
app.state.store, app.state.notifier = store, notifier
request_stats: dict[str, RequestStats] = {}
def make_stats(app):
request_stats["mw"] = RequestStats(app)
return request_stats["mw"]
app.add_middleware(make_stats)
def auth(request: Request, authorization: str = Header(default="")) -> None:
"""The controller token has full access. An agent token (docs/spawn.md) acts as that
agent, scoped to itself, its subtree and prompting its parent."""
if token and secrets.compare_digest(authorization, f"Bearer {token}"):
return
bearer = authorization.removeprefix("Bearer ")
agent = agent_for_token(store, bearer) if bearer != authorization else None
if agent is None:
raise HTTPException(401, "bad or missing bearer token")
route = getattr(request.scope.get("route"), "path", "")
if not agent_may(
store, agent, request.method, route, request.path_params, request.query_params
):
raise HTTPException(403, f"agent {agent['name']} may not call {request.method} {route}")
request.state.agent = agent
api = APIRouter(dependencies=[Depends(auth)])
def spec_or_404(swarm: str) -> Row:
row = store.get_swarm(swarm)
if row is None:
raise HTTPException(404, f"no swarm {swarm!r}")
return row
def agent_or_404(name: str) -> Row:
a = store.get_agent(name)
if a is None:
raise HTTPException(404, f"no agent {name!r}")
return a
@app.get("/healthz")
def healthz() -> dict:
mw = request_stats.get("mw")
return {"ok": True, **(stats() if stats else {}), "process": process_stats(),
"requests": mw.snapshot() if mw else {}}
@app.get("/", response_class=HTMLResponse)
def index() -> str:
return _status_page(store, clock().timestamp())
# ------------------------------------------------------------- swarms
@api.get("/swarms")
def list_swarms() -> list[SwarmStatus]:
now = clock().timestamp()
return [swarm_status(store, sw["spec"], now) for sw in store.list_swarms()]
@api.put("/swarms/{swarm}")
def apply(swarm: str, spec: SwarmSpec) -> SwarmStatus:
if spec.swarm != swarm:
raise HTTPException(400, "spec.swarm does not match the path")
for type_name in spec.types:
owner = store.type_owner(type_name)
if owner not in (None, swarm):
raise HTTPException(409, f"type {type_name!r} already belongs to swarm {owner!r}")
if conflicts := worker_cap_conflicts(store, spec):
raise HTTPException(409, "; ".join(conflicts))
store.put_swarm(spec, clock().timestamp())
return swarm_status(store, spec, clock().timestamp())
@api.post("/swarms/{swarm}/preflight")
async def preflight(
swarm: str, spec: Annotated[SwarmSpec | None, Body()] = None
) -> PreflightReport:
"""Probe every provider-backed model in `spec` (or the applied spec when no body is
sent) with one small tool-calling request. Nothing is stored."""
if spec is None:
spec = spec_or_404(swarm)["spec"]
elif spec.swarm != swarm:
raise HTTPException(400, "spec.swarm does not match the path")
async with httpx.AsyncClient(transport=preflight_transport) as http:
return await run_preflight(spec, secret_source, http)
@api.get("/swarms/{swarm}")
def get_swarm(swarm: str) -> dict:
row = spec_or_404(swarm)
status = swarm_status(store, row["spec"], clock().timestamp())
return {
"spec": row["spec"].model_dump(mode="json"),
"status": status.model_dump(mode="json"),
"removing": bool(row["removing"]),
}
@api.delete("/swarms/{swarm}", status_code=202)
def remove(swarm: str) -> dict:
spec_or_404(swarm)
store.set_removing(swarm)
return {"swarm": swarm, "removing": True}
@api.get("/swarms/{swarm}/agents")
def list_agents(
swarm: str,
type: str | None = None,
state: AgentState | None = None,
cursor: str | None = None,
limit: int = 500,
parent: str | None = None,
) -> dict:
spec = spec_or_404(swarm)["spec"]
now = clock().timestamp()
workers = {w["id"]: w for w in store.list_workers(swarm)}
pending = store.pending_counts(swarm)
kids = store.children_by_parent(swarm)
out: list[AgentStatus] = []
rows = sorted(store.list_agents(swarm, type, parent=parent), key=lambda a: a["name"])
for a in rows:
if cursor is not None and a["name"] <= cursor:
continue
st = agent_status(a, workers.get(a["worker"]), spec, pending.get(a["name"], 0), now,
kids.get(a["name"]))
if state is None or st.state == state:
out.append(st)
if len(out) >= max(1, limit):
break
more = len(out) >= max(1, limit) and out[-1].name != rows[-1]["name"]
return {
"agents": [x.model_dump(mode="json") for x in out],
"cursor": out[-1].name if more else None,
}
# ------------------------------------------------------------- agents
@api.get("/agents/{name}")
def get_agent(name: str) -> AgentStatus:
a = agent_or_404(name)
row = store.get_swarm(a["swarm"])
w = store.get_worker(a["worker"]) if a["worker"] else None
pending = store.pending_counts(a["swarm"]).get(name, 0)
kids = [c["name"] for c in store.list_agents(parent=name)]
return agent_status(a, w, row["spec"] if row else None, pending, clock().timestamp(), kids)
@api.post("/agents/{name}/spawn", status_code=201)
def spawn(name: str, req: SpawnRequest) -> SpawnAck:
try:
ack, created = spawn_child(store, name, req, clock().timestamp())
except KeyError:
raise HTTPException(404, f"no agent {name!r}") from None
except Refused as r:
return JSONResponse({"reason": r.reason, "detail": r.message}, status_code=409)
if not created:
return JSONResponse(ack.model_dump(mode="json"), status_code=200)
return ack
@api.delete("/agents/{name}")
def remove_agent(name: str) -> dict:
a = agent_or_404(name)
if a["parent"] is None:
return JSONResponse(
{"reason": "not_spawned", "detail": "replicas are removed by scaling their type"},
status_code=409,
)
removed = remove_subtree(store, name, "removed", clock().timestamp())
store.listener("reconcile", "")
return {"removed": [r["name"] for r in removed]}
@api.get("/whoami")
def whoami(request: Request) -> dict:
a = getattr(request.state, "agent", None)
if a is None:
return {"kind": "controller"}
row = store.get_swarm(a["swarm"])
return {
"kind": "agent",
"name": a["name"],
"swarm": a["swarm"],
"type": a["type"],
"parent": a["parent"],
"depth": agent_depth(row["spec"] if row else None, a),
"children": [c["name"] for c in store.list_agents(parent=a["name"])],
}
@api.post("/agents/{name}/prompt")
def prompt(name: str, req: PromptRequest) -> PromptAck:
a = agent_or_404(name)
cmd = PromptCommand(
agent=name,
prompt_id=uuid.uuid4().hex,
text=req.text,
timeout=req.timeout,
reply_to=req.reply_to,
)
now = clock().timestamp()
store.add_prompt(name, cmd.model_dump_json(), now)
w = store.get_worker(a["worker"]) if a["worker"] else None
live = w is not None and worker_state(w, now) == WorkerState.running
return PromptAck(
prompt_id=cmd.prompt_id, agent=name, status="queued" if live else "pending"
)
@api.post("/swarms/{swarm}/prompts")
def bulk_prompt(swarm: str, req: BulkPromptRequest) -> BulkPromptAck:
"""The same prompt to every agent of a type (optionally only those in `state`), in one
request: one pending prompt per agent, delivered and admitted (`max_working`) exactly
as `POST /agents/{name}/prompt` would."""
row = spec_or_404(swarm)
if row["removing"]:
raise HTTPException(409, f"swarm {swarm!r} is being removed")
if req.type not in row["spec"].types:
raise HTTPException(404, f"no type {req.type!r} in swarm {swarm!r}")
ack = BulkPromptAck(swarm=swarm, type=req.type, matched=0, queued=0, pending=0)
return prompt_many(swarm, store.list_agents(swarm, req.type), req, ack)
@api.post("/agents/{name}/children/prompts")
def children_prompt(name: str, req: ChildrenPromptRequest) -> BulkPromptAck:
"""The same prompt to every direct child of `name` (optionally one type / state), in
one request, with the rules of `POST /swarms/{swarm}/prompts`. The agent's own token
may call it (docs/spawn.md), so a leader prompts 100 children in one request."""
parent = agent_or_404(name)
if parent["removing"]:
raise HTTPException(409, f"agent {name!r} is being removed")
kids = store.list_agents(parent["swarm"], req.type, parent=name)
ack = BulkPromptAck(swarm=parent["swarm"], type=req.type, parent=name, matched=0,
queued=0, pending=0)
return prompt_many(parent["swarm"], kids, req, ack)
def prompt_many(swarm: str, agents: list[Row], req: BulkPromptRequest | ChildrenPromptRequest,
ack: BulkPromptAck) -> BulkPromptAck:
"""One pending prompt per matching agent, delivered and admitted (`max_working`)
exactly as `POST /agents/{name}/prompt` would. `skip_pending` (default on with
state=idle) skips agents that already have an undelivered prompt."""
now = clock().timestamp()
workers = {w["id"]: w for w in store.list_workers(swarm)}
skip_pending = req.state == AgentState.idle if req.skip_pending is None else req.skip_pending
pending = store.pending_counts(swarm) if skip_pending else {}
rows: list[tuple[str, str]] = []
for a in sorted(agents, key=lambda a: a["name"]):
ack.matched += 1
w = workers.get(a["worker"])
if a["removing"]:
ack.skipped_removing += 1
continue
if req.state is not None and turn_state(a, w, now) != req.state:
ack.skipped_state += 1
continue
if pending.get(a["name"]):
ack.skipped_pending += 1 # run 1k: 645 calls stacked 73,394 prompts
continue
cmd = PromptCommand(agent=a["name"], prompt_id=uuid.uuid4().hex, text=req.text,
timeout=req.timeout, reply_to=req.reply_to)
rows.append((a["name"], cmd.model_dump_json()))
if w is not None and worker_state(w, now) == WorkerState.running:
ack.queued += 1
else:
ack.pending += 1
store.add_prompts(rows, now)
return ack
@api.get("/agents/{name}/events")
async def events(name: str, after: int = 0, wait: float = 0, limit: int = 1000) -> dict:
if store.get_agent(name) is None and store.event_count(name) == 0:
raise HTTPException(404, f"no agent {name!r}")
after = max(0, after)
await notifier.long_poll(f"events:{name}", lambda: store.event_count(name) > after, wait)
evs = store.read_events(name, after, limit=max(1, min(limit, 5000)))
return {"events": evs, "next": after + len(evs)}
# ------------------------------------------------------------- workers
@api.get("/workers")
def list_workers(swarm: str | None = None, type: str | None = None) -> list[WorkerStatus]:
now = clock().timestamp()
by_worker: dict[str, list[str]] = {}
for a in store.list_agents(swarm, type):
if a["worker"]:
by_worker.setdefault(a["worker"], []).append(a["name"])
return [
worker_status(w, by_worker.get(w["id"], []), now)
for w in store.list_workers(swarm, type)
]
def worker_or_404(worker_id: str) -> Row:
w = store.get_worker(worker_id)
if w is None:
raise HTTPException(404, f"no worker {worker_id!r}")
return w
@api.get("/workers/{worker_id}")
def get_worker(worker_id: str) -> WorkerStatus:
w = worker_or_404(worker_id)
names = [a["name"] for a in store.list_agents(worker=worker_id)]
return worker_status(w, names, clock().timestamp())
def stale(w: Row, incarnation: str | None) -> bool:
"""The caller is not the slot's current job. Workers that send no incarnation (older
versions) are trusted, as before."""
return incarnation is not None and w["incarnation"] != incarnation
def provider_cap(spec: SwarmSpec, type_name: str) -> tuple[str, int] | None:
"""(provider name, max_working) when admission is enforced for this type's provider."""
ts = spec.types.get(type_name)
r = ts.resolved_model if ts else None
if not enforce_max_working or r is None or r.provider.max_working is None:
return None
return r.provider_name, r.provider.max_working
def busy(a: Row, w: Row | None, now: float) -> bool:
"""In a turn, or handed a prompt to start one, as far as the controller knows."""
if w is None or worker_state(w, now) == WorkerState.dead:
live.pop(a["name"], None)
return False
seen = live.get(a["name"])
if seen is not None:
return seen[0] != "idle"
return agent_state(a, w, now) == AgentState.working
def turn_state(a: Row, w: Row | None, now: float) -> AgentState:
"""`agent_state`, with working/idle corrected by what the controller learned since the
heartbeat (`live`): a prompt just handed out makes it working, a turn_ended event idle.
Used by the bulk prompt's `state` filter so it neither re-prompts an agent whose turn
is starting nor waits a heartbeat for one whose turn just ended."""
st = agent_state(a, w, now)
seen = live.get(a["name"])
if seen is None or st not in (AgentState.idle, AgentState.working):
return st
return AgentState.idle if seen[0] == "idle" else AgentState.working
def note_started(names: set[str], now: float) -> None:
"""Uncapped providers: remember prompts handed to agents not in a turn (`live`), as
admission does for capped ones, so `turn_state` sees the turn start at once."""
workers: dict[str, Row | None] = {}
for name in names:
seen = live.get(name)
if seen is not None and seen[0] != "idle":
continue
a = store.get_agent(name)
if a is None:
continue
if a["worker"] not in workers:
workers[a["worker"]] = store.get_worker(a["worker"]) if a["worker"] else None
if seen is None and agent_state(a, workers[a["worker"]], now) == AgentState.working:
continue
live[name] = ("admitted", now)
def admission_view(spec: SwarmSpec, provider: str, cap: int, now: float
) -> tuple[set[str], list[str], dict[str, str | None]]:
"""(busy agents, admission window, agent -> worker) for one provider. The window is
the agents that get the provider's free slots: not busy, on a running worker, ordered
by their oldest pending prompt across all workers (FIFO), at most `cap - busy` long."""
users = {t for t, x in spec.types.items() if x.provider_name == provider}
workers = {x["id"]: x for x in store.list_workers(spec.swarm)}
taken: set[str] = set()
owner: dict[str, str | None] = {}
for a in store.agent_states(spec.swarm, users):
owner[a["name"]] = a["worker"]
if busy(a, workers.get(a["worker"]), now):
taken.add(a["name"])
free = cap - len(taken)
window: list[str] = []
if free > 0:
for name in store.oldest_pending(spec.swarm, users):
w = workers.get(owner.get(name))
if name in taken or w is None or w["job_id"] is None or w["draining"] \
or w["retire_at"] or worker_state(w, now) != WorkerState.running:
continue # a worker that cannot start the turn must not hold a slot
window.append(name)
if len(window) >= free:
break
return taken, window, owner
def admit(w: Row, prompts: list[Row]) -> list[Row]:
"""Provider `max_working` at prompt admission (design.md section 5). A prompt for an
agent in a turn always goes out (it joins that turn). A prompt that would start a turn
needs a free slot, and free slots go to pending prompts in FIFO order of creation
across all workers of the provider (`admission_view`), not to whichever worker polls
first: others stay queued here and go out on a later poll.
Slots: agents whose fresh heartbeat says working, overridden by what the controller
learned since that heartbeat (`live`): a prompt handed out takes the slot at once (so
two polls between heartbeats cannot both take the last slot), and a turn_ended /
turn_interrupted event releases it at once, without waiting for the next heartbeat.
Still soft by about one heartbeat: a heartbeat built before the worker saw an event
can briefly overrule it (see `heartbeat_seen`)."""
if not prompts:
return prompts
sw = store.get_swarm(w["swarm"])
cap = provider_cap(sw["spec"], w["type"]) if sw else None
now = clock().timestamp()
if cap is None:
note_started({p["agent"] for p in prompts}, now)
return prompts
taken, window, _ = admission_view(sw["spec"], cap[0], cap[1], now)
allowed = set(window)
out = []
for p in prompts:
name = p["agent"]
if name not in taken:
if name not in allowed:
continue # no slot for it yet: stays queued
taken.add(name)
live[name] = ("admitted", now)
out.append(p)
return out
def wake_window(swarm: str, providers: set[str]) -> None:
"""A slot was released: wake the polls of the workers whose agents now get it."""
sw = store.get_swarm(swarm)
if sw is None:
return
spec, now = sw["spec"], clock().timestamp()
for prov in providers:
cap = spec.providers.get(prov)
if cap is None or cap.max_working is None:
continue
_, window, owner = admission_view(spec, prov, cap.max_working, now)
for wid in {owner[n] for n in window if owner.get(n)}:
notifier.notify(f"commands:{wid}")
def turn_seen(a: Row, evs: list, now: float) -> bool:
"""Apply an agent's turn events to `live`; True if that released its slot. Events
are in the worker's order, and the batch is newer than any of them. A turn_ended with
no turn_started after a fresh admission belongs to an earlier turn: ignored."""
was = live.get(a["name"])
state = was[0] if was else None
for ev in evs:
if ev.type == "turn_started":
state = "working"
elif ev.type == "prompt_deferred" or (
ev.type in ("turn_ended", "turn_interrupted") and state != "admitted"
):
state = "idle"
if state is None or (was and state == was[0]):
return False
live[a["name"]] = (state, now)
return state == "idle"
def heartbeat_seen(hb: WorkerHeartbeat, now: float) -> bool:
"""A heartbeat is the source of truth again for the agents it reports, except a
fresh admission (< ADMIT_GRACE) it reports idle: that heartbeat was most likely
built before the worker received the prompt. True if it released a slot."""
released = False
for ah in hb.agents:
seen = live.get(ah.name)
if seen is None:
continue
if seen[0] == "admitted" and ah.state != "working" and now - seen[1] < ADMIT_GRACE:
continue
del live[ah.name]
released |= seen[0] != "idle" and ah.state != "working"
return released
def seen(w: Row) -> None:
"""Any request from the slot's current job proves it alive (reconcile.last_seen).
Written at most every SEEN_EVERY seconds per worker."""
now = clock().timestamp()
if w["job_id"] is not None and now - (w.get("last_seen") or 0.0) >= SEEN_EVERY:
store.update_worker(w["id"], last_seen=now)
@api.get("/workers/{worker_id}/commands")
async def commands(worker_id: str, wait: float = 25, incarnation: str | None = None):
w0 = worker_or_404(worker_id)
if stale(w0, incarnation):
raise HTTPException(409, "worker incarnation is not the slot's current job")
seen(w0)
def check():
w = store.get_worker(worker_id)
if w is None or stale(w, incarnation):
return "stale" # replaced while this poll was parked: never hand it commands
if w["job_id"] is None:
return None # slot has no live job (stale process): give it nothing
cmds = store.commands_for(worker_id)
# A draining worker starts no turns; its prompts wait for the replacement job.
draining = w["draining"] or w["retire_at"]
prompts = [] if draining else admit(w, store.prompts_for_worker(worker_id))
return (cmds, prompts) if cmds or prompts else None
found = await notifier.long_poll(f"commands:{worker_id}", check, wait)
if found == "stale":
raise HTTPException(409, "worker incarnation is not the slot's current job")
if not found:
return CommandBatch(commands=[])
cmds, prompts = found
batch = CommandBatch(
commands=[_COMMAND.validate_json(c["body"]) for c in cmds]
+ [PromptCommand.model_validate_json(p["body"]) for p in prompts]
)
def ack() -> None: # at-least-once: forget them only after the response went out
store.delete_commands([c["id"] for c in cmds])
store.delete_prompts([p["id"] for p in prompts])
return JSONResponse(batch.model_dump(mode="json"), background=BackgroundTask(ack))
@api.post("/workers/{worker_id}/heartbeat")
def heartbeat(worker_id: str, hb: WorkerHeartbeat, incarnation: str | None = None) -> dict:
if stale(worker_or_404(worker_id), incarnation):
raise HTTPException(409, "worker incarnation is not the slot's current job")
if hb.worker != worker_id:
raise HTTPException(400, "heartbeat worker does not match the path")
if not record_heartbeat(store, worker_id, hb, clock()):
raise HTTPException(409, "worker slot has no live job")
w = store.get_worker(worker_id)
sw = store.get_swarm(w["swarm"]) if w else None
cap = provider_cap(sw["spec"], w["type"]) if sw else None
if heartbeat_seen(hb, clock().timestamp()) and cap is not None:
wake_window(w["swarm"], {cap[0]})
return {"ok": True}
@api.post("/workers/{worker_id}/events")
def post_events(worker_id: str, batch: EventBatch, incarnation: str | None = None) -> dict:
w = worker_or_404(worker_id)
if not stale(w, incarnation): # a replaced job's last events are still accepted
seen(w)
grouped: dict[str, list] = {}
for ev in batch.events:
grouped.setdefault(ev.agent, []).append(ev)
now = clock().timestamp()
sw = store.get_swarm(w["swarm"])
cap = provider_cap(sw["spec"], w["type"]) if sw else None
released = False
for agent, evs in grouped.items():
a = store.get_agent(agent)
store.append_events(a["swarm"] if a else w["swarm"], agent, evs)
if a is not None and a["worker"] == worker_id:
released |= turn_seen(a, evs, now)
if released and cap is not None: # slots freed now, not at the next heartbeat (run-1k finding 1)
wake_window(w["swarm"], {cap[0]})
return {"ok": True, "accepted": len(batch.events)}
app.include_router(api)
return app