Syncs AI agents so no context gets lost

Agent-to-agent handoffs in two lines of code. One agent passes context, another catches it. Any framework, any model.

pnpm add @b4tonhq/b4ton

Available for these agents

Quickstart

Install the SDK, then pass and catch.

pnpm add @b4tonhq/b4ton

Agent A — pass

Finish your work and hand it off

Code

import Baton from "b4ton";

const baton = new Baton("baton_abc123...");

// Agent A: pass context to the next agent
const handoff = await baton.pass({
  task: "Review and improve this draft",
  output: { draft: "Hello, I wanted to follow up..." },
});

console.log(handoff.pickup_url);
// -> https://b4ton.sh/api/catch/abc-123

Agent B — catch

Pick up the baton and continue

Code

// Agent B: pick up the baton and do the work
const job = await baton.catch(handoff.pickup_url);

console.log(job.task);    // "Review and improve this draft"
console.log(job.output);  // { draft: "Hello, I wanted to follow up..." }

// When done, mark it complete
await baton.done(job.baton_id, {
  output: { revised: "Dear colleague, ..." },
});

That's it. No shared runtime, no framework coupling, no vendor lock-in.

How It Works

Four steps. No shared runtime, no framework lock-in.

Agent A passes

An agent finishes its work and POSTs the output, task instructions, and context to Baton.

Baton holds

The context is stored with a unique URL. It sits there until another agent picks it up or the TTL expires.

Agent B catches

Any agent GETs the baton URL to receive the full payload — task, output, context, and constraints.

Agent B finishes

When done, the agent marks the baton complete and optionally attaches its own output.

pending → caught → done
↘ expired (at any point)

API Reference

Don't want the SDK? Hit the endpoints directly. All require a Bearer token.

POST

/api/pass

Hand off context to another agent

Code

curl -X POST https://b4ton.sh/api/pass \
  -H "Authorization: Bearer baton_abc123..." \
  -H "Content-Type: application/json" \
  -d '{
    "task": "Review this draft email",
    "output": { "draft": "Hello..." },
    "context": { "tone": "professional" }
  }'

GET

/api/catch/:id

Pick up a baton and start working

Code

curl https://b4ton.sh/api/catch/<baton_id> \
  -H "Authorization: Bearer baton_abc123..."

POST

/api/done/:id

Mark work as complete

Code

curl -X POST https://b4ton.sh/api/done/<baton_id> \
  -H "Authorization: Bearer baton_abc123..." \
  -H "Content-Type: application/json" \
  -d '{ "output": { "result": "Done!" } }'

GET

/api/status/:id

Check baton status without side effects

Code

curl https://b4ton.sh/api/status/<baton_id> \
  -H "Authorization: Bearer baton_abc123..."