Fabric Swarm

Fabric Swarm

Build from Fabric primitives; do not install a messenger or swarm extension.

• Persistent identities: agents.create; asynchronous delegation: agents.tell (ask only when blocking is necessary).
• Durable events and history: mesh.publish / mesh.read; presence: mesh.members.
• Atomic claims, leases, and decisions: mesh.put({ ..., ifVersion }).

Choose a short run key and topic such as team.auth-migration. Store tasks under runs/<run>/tasks/<id> with ifVersion: 0; include title, status, owner, dependencies, progress, and result.

Actor instructions must require workers to verify every dependency task is complete, claim only ready work with ifVersion equal to the observed version, stop after a failed claim, publish progress, update blocked/completed state with the version returned by the preceding successful read/write, CAS-unblock dependents only after all their dependencies complete, direct questions with mesh.publish({ topic, to, ... }), respect path ownership, and emit directives only for blockers or final results.

const run = π.run;
const topic = `team.${run}`;
const tasks = JSON.parse(π.tasks) as Array<{
  id: string;
  title: string;
  detail: string;
  dependencies?: string[];
}>;
const roles = JSON.parse(π.roles) as Array<{ name: string; instructions: string }>;

await workflow.configure({
  name: `Swarm · ${run}`,
  description: "Persistent actors coordinating through durable shared tasks",
});
await phase("Seed tasks", { total: tasks.length });
for (const task of tasks) {
  await mesh.put({
    key: `runs/${run}/tasks/${task.id}`,
    value: {
      ...task,
      dependencies: task.dependencies ?? [],
      status: (task.dependencies?.length ?? 0) > 0 ? "blocked" : "ready",
      owner: null,
      progress: [],
      result: null,
    },
    ifVersion: 0,
  });
}

await phase("Create actors", { total: roles.length });
const actors = await Promise.all(
  roles.map((role) =>
    agents.create({
      name: role.name,
      runner: "pi",
      instructions: role.instructions,
      topics: [topic],
      responseMode: "directive",
      delivery: "mailbox",
      coalesce: false,
    }),
  ),
);

await phase("Dispatch", { total: actors.length });
for (const actor of actors) {
  await agents.tell({
    id: actor.id,
    message: `Join ${topic}. Inspect ready tasks under runs/${run}/tasks/ and atomically claim one matching your role.`,
  });
}
await mesh.publish({
  topic,
  kind: "run.started",
  data: { run, actors: actors.map(({ id, name }) => ({ id, name })) },
});
return { run, topic, actors, taskPrefix: `runs/${run}/tasks/` };

Pass the run key as strings.run, tasks as JSON strings.tasks, and role instructions as JSON strings.roles. Keep coordination pull-based: inspect topic history, task state, and mailboxes at decision points rather than polling continuously inside one execution. Partition file ownership. Use agents.steer only for a running one-shot worker; persistent actors receive tell/ask mail.