One plugin.
Every agent stream.
Durable by default.

Bring your Mastra supervisor and subagents. Super Harness composes into the super-line host you already own and persists every nested stream as one replayable session tree.

Add the plugin Run the Mastra example

One server, connection, authentication system, and collections backend.

Your existingsuper-line host

socket
auth
storage

plugins: [harness(engine)]

● supervisororchestrating

├─todo · 3 / 3complete

├─delegate → researcherstreaming

│ ├─reasoningcomplete

│ ├─search_webcomplete

│ └─answerstreaming

├─collab → scene.doc · typed CRDT2 co-writers

└─approval: deployapproved

Supervisor and subagent branches persist through super-line collections, while humans and agents collaborate on the same typed CRDT state.

The integration boundary

Your host stays yours.

Super Harness joins your super-line server as a plugin. It doesn't introduce another service for your team to authenticate, deploy, or reconcile.

pnpm add @super-harness/core @super-harness/server @mastra/core

server.tsRead the complete guide →

import { createHarness } from '@super-harness/core'
import { harness } from '@super-harness/server'
import { harnessContract } from '@super-harness/shared'

const engine = createHarness({
  supervisor,
  subagents: [{ agent: researcher }],
})

const app = defineContract({
  plugins: [harnessContract()],
  roles: { user: {} },
})

createSuperLineServer(app, {
  transports,
  collections,
  authenticate,
  identify: (connection) => connection.ctx.userId,
  plugins: [harness(engine)],
})

Built for the run, not the transcript

Keep the structure that made the work happen.

Preserve hierarchy

Supervisor and subagents remain first-class branches, not generic events.

Persist the stream

Reconnects and late joiners rebuild the same session without replay glue.

Control the right moment

Ask for input or approval inside the durable run, then continue it exactly.

A working run is the proof

Start with the host you already have.

Add the plugin →Run the Mastra example →

One plugin.Every agent stream. Durable by default.