@fabric-harness/client

Typed HTTP client for TechFabric Harness servers.

Agent interactions ride the durable submission lifecycle: send is fire-and-forget (202 + submission id + offset-addressed stream), updates multiplexes durable records with token and reasoning deltas over reconnecting SSE, reply reads a canonical response after settlement, abort records a durable abort, and prompt is the synchronous convenience. Finite jobs support synchronous results and durable run receipts.

npm install @fabric-harness/client

import { createFabricClient } from '@fabric-harness/client';

const client = createFabricClient({
  baseUrl: 'http://localhost:4317',
  headers: { authorization: `Bearer ${process.env.FABRIC_HARNESS_TOKEN}` },
});

// Bind a durable conversation once.
const support = client.agent({ agent: 'support', id: 'user-42' });
const sent = await support.send('hello');

// Reattach in this or a later process using only the submission id.
const reply = await support.read(sent.submissionId, { timeoutMs: 30_000 });
console.log(reply.text);

// Live tail durable records plus transient token/reasoning deltas.
for await (const update of support.updates()) {
  if (update.type === 'delta') process.stdout.write(update.delta);
}

// Synchronous convenience, and finite jobs.
const { result } = await client.agents.prompt({ agent: 'support', id: 'user-42', message: 'status?' });
const jobResult = await client.jobs.invoke('daily-report', { day: '2026-07-08' });

// Durable finite run: admit, inspect/observe, and abort without a long HTTP request.
const run = await client.jobs.invoke(
  'daily-report',
  { day: '2026-07-08' },
  { wait: false, idempotencyKey: 'daily-report:2026-07-08' },
);
const status = await client.runs.get(run.runId);
const recent = await client.runs.list({ job: 'daily-report', limit: 20 });
for await (const event of client.runs.observe(run.runId)) console.log(event);
await client.runs.abort(run.runId);

// Durable abort for everything unsettled on the instance session.
await client.agents.abort({ agent: 'support', id: 'user-42' });

Deployment conformance polls bounded transient health/readiness failures before invoking model or job routes:

import { assertDeploymentConformance } from '@fabric-harness/client';

await assertDeploymentConformance({
  target: 'databricks-app',
  baseUrl: process.env.DATABRICKS_APP_URL!,
  job: { name: 'smoke' },
  timeoutMs: 120_000,
  pollIntervalMs: 1_000,
  signal: AbortSignal.timeout(125_000),
});

HTTP 502, 503, and 504, network startup failures, and non-ready bodies are retried. Permanent HTTP failures fail fast, and lifecycle routes are not invoked before readiness.

Apache-2.0