CAP Node/TypeScript SDK

Node/TS SDK with NATS helpers. Uses protobufjs to load CAP proto definitions at runtime.

Quick Start

1. Install deps:
``bash
cd sdk/node
npm install
`
2. Run the sample worker:
`bash
npm run build
node dist/sample-worker.js
`

3. Submit a job (client):
`ts
import { connectNATS } from "./bus";
import { submitJob } from "./client";

async function main() {
const nc = await connectNATS({ url: "nats://127.0.0.1:4222" });
await submitJob(
nc,
{
jobId: "job-echo-1",
topic: "job.echo",
contextPtr: "redis://ctx/job-echo-1",
},
"trace-1",
"client-node",
""
);
await nc.drain();
}

main().catch(console.error);
`

Files


- src/protos.ts — loads CAP protos via protobufjs.
- src/bus.ts — NATS connector.
- src/worker.ts — worker skeleton.
- src/client.ts — submission helper.
- src/sample-worker.ts — minimal echo worker example.

Runtime (High-Level SDK)

The runtime hides NATS/Redis plumbing and gives you typed handlers.

`ts
import { z } from "zod";
import { Agent } from "./runtime";

const Input = z.object({ prompt: z.string() });
const Output = z.object({ summary: z.string() });

const agent = new Agent({ retries: 2 });

agent.job("job.summarize", Input, async (_ctx, data) => {
return { summary: data.prompt.slice(0, 140) };
}, { outputSchema: Output });

agent.run().catch(console.error);
`

$3


- NATS_URL (default nats://127.0.0.1:4222)
- REDIS_URL (default redis://127.0.0.1:6379/0)

Notes

- Subjects: sys.job.submit, job., sys.job.result, sys.heartbeat.
- Protocol version: 1.
- Field names use camelCase in protobufjs objects (e.g., jobId, contextPtr, resultPtr, workerId).
- Swap bus.ts for another transport if needed; keep message encoding via protobufjs or precompiled static modules (pbjs/pbts).
- Signing: submitJob and startWorker sign envelopes when given a PEM private key; set publicKeyMap to verify incoming packets. Signatures use deterministic protobuf serialization (map entries ordered by key) for cross-SDK verification. Generate a P-256 keypair with:
`bash
node -e "const {generateKeyPairSync}=require('crypto');const {privateKey,publicKey}=generateKeyPairSync('ec',{namedCurve:'prime256v1',publicKeyEncoding:{type:'spki',format:'pem'},privateKeyEncoding:{type:'pkcs8',format:'pem'}});console.log(privateKey);console.log(publicKey);"
`
- If you do not want signature verification, omit publicKeyMap in startWorker.
- Pass undefined as the private key to submitJob` to send unsigned envelopes.