Free and open source for macOS, Windows and Linux

Nine agents.
One repo.
No collisions.

Claude Code, Codex and OpenCode side by side, each in its own git worktree. A central Brain hands out the work. Verification gates prove it before it counts as done.

macOS, Linux

curl --proto '=https' --tlsv1.2 -fsSL https://ninebrains.dev/install | sh

Installs or updates. Checks the SHA256 first. No Gatekeeper warning on macOS.

irm https://ninebrains.dev/install.ps1 | iex

Installs or updates for your user. No admin needed.

Works with Claude Code Codex OpenCode

4: lanes a tab
3: gate attempts
0: telemetry
<5s: to STOP every run

Ninebrainsdocs-site LIVE · LANES

Claude Codelanes/5f15076b

> job j2 search-ui

⏺ Edit src/search/SearchBox.tsx

+42 -3

✻ writing tests

Codexlanes/1382dc71

> job j1 index-content

• Ran node scripts/build-index.ts

wrote search-index.json

✓ done, j2 and j3 unblocked

OpenCodelanes/c9ba2b08

> job j3 search-api

read git status, git diff

writing src/server/search.ts

▸ running tests

OpenCodelanes/b50989a2

> job j4 search-docs

gate: screenshot at 390

✗ nav overlaps the input

feedback sent, attempt 2 of 3

01 Lanes

Every agent gets its own world.

Its own git worktree and branch, terminal, editor and browser. Four lanes to a tab, as many tabs as you want. They cannot touch each other's files, so nothing merges by accident. Its own git worktree, branch, terminal, editor and browser. Lanes cannot touch each other's files, so nothing merges by accident.

Ninebrainsdocs-site LIVE · LANES

Lanes Tab 1 4 Tab 2 2 + Planner Brain STOP

docs-sitelanes/5f15076bClaude

✻ Claude Code · job j2 search-ui

> Build the search box for the docs

⏺ Read(src/components/Header.tsx) 88 lines

⏺ Edit(src/search/SearchBox.tsx)

⎿ +42 -3

⏺ Bash(pnpm test search)

⎿ 12 passed

✻ Adding the ⌘K shortcut

docs-sitelanes/1382dc71Codex

codex · job j1 index-content

> index every page in src/content

• Ran rg --files src/content 128

• Edited scripts/build-index.ts

└ +88

• Ran node scripts/build-index.ts

└ wrote search-index.json

✓ j1 done, now verifying

docs-sitelanes/c9ba2b08OpenCode

opencode · job j3 search-api

> add /api/search on the index

▸ reading src/server/routes.ts

▸ writing src/server/search.ts

+61

▸ registering GET /api/search

▸ running tests

docs-sitelanes/b50989a2OpenCode

› Ready for the next job.

opencode · job j4 search-docs

> document the search shortcut

| Edit docs/guide/search.md

+24

| Read src/search/SearchBox.tsx

| writing the shortcuts table

4 running ⎇ lanes/5f15076b job j2 · running 00:00

02 The Brain

One plan, handed out as it unblocks.

The Brain turns a brief into a graph of jobs with dependencies, plus a mailbox the lanes can talk through. A job goes to whichever lane is idle, the moment everything it depends on is done. Its status is one click away from Settings, and Arena shows it across every project you have open at once. The Brain turns a brief into a graph of jobs and hands each one to an idle lane the moment its dependencies are done.

Ninebrainsdocs-site LIVE · THE BRAIN

Lanes Tab 1 4 + Planner Brain STOP

lane 1Claude

› Ready for the next job.

› j2 search-ui

lane 2Codex

› Ready for the next job.

› j1 index-content

✓ j1 done

lane 3OpenCode

› Ready for the next job.

› j3 search-api

lane 4Codex

› Ready for the next job.

› j4 search-docs

Brain dispatching PlanPause

> add search to the docs site, ⌘K

Brain 1 · planning in jobs j1 to j5

⏺ brain.create_job × 5

⏺ brain.link j1 → j2, j3, j4

Queue

j1 index-content queued→ lane 2

j2 search-ui queued→ lane 1

j3 search-api queued→ lane 3

j4 search-docs queued→ lane 4

j5 review waits on j2 to j4

3 ready 2 running 1 done

Inboxes lane 2 1 unread

Brain 1 · Claude Code 5 jobs · 4 edges 00:00

03 Verification gates

No agent grades its own work.

When a lane says it is done, a second run has to prove it: the tests, screenshots at three widths, a read-only reviewer. A failed gate sends the evidence back, up to three attempts, then blocks the job and tells you. When a lane says it is done, a second run proves it: tests, screenshots at three widths, a read-only reviewer. Up to three attempts.

Ninebrainsdocs-site LIVE · GATES

Job verification j2 search-ui Verifying Verified

Attempt 1 Failed, sent back

✓ Tests 41 of 41 · 3.9 s

✗ Screenshots 390 · 768 · 1440

[mobile 390px] the nav overlaps the search input

→ feedback and evidence sent to lane 1, attempt 2 of 3

Attempt 2 Passed

✓ Tests 41 of 41 · 3.7 s

✓ Screenshots no overlap

✓ Reviewer Read, Grep, Glob only

2 attempts · 1 of 3 failures allowed used · Every gate passed.

1440 px

768 px

390 px

reviewer · read-only checkout

{ "verdict": "pass",

"notes": "input clears the nav at 390" }

reviewer · Claude Code ⎇ lanes/5f15076b evidence/j2/2 00:00

04 Planner

Draw the plan. Run the plan.

Jobs are nodes, dependencies are edges. Run plan compiles the canvas into Brain jobs, idempotently, and refuses a graph with a cycle in it. Jobs are nodes, dependencies are edges. Run plan compiles the canvas into Brain jobs and refuses a graph with a cycle.

Ninebrainsdocs-site LIVE · PLANNER

Launch login + Job Note Module ▷ Run plan ▷ Run plan ▷ Run plan ▷ Run plan ▷ Run plan

▤ Backend1 job

JOB Done

Design the auth schema

tests

JOB DraftReady

Magic-link API

tests

JOB DraftWaiting

screenshot

JOB DraftWaiting

Email sender

tests

REVIEW DraftWaiting

Security review

reviewer

NOTE

Magic links only. No passwords in v0.1.

The plan has a dependency cycle

Design the auth schema → Magic-link API → Login page UI → Security review → Design the auth schema

✓

Plan compiled

5 created, 0 updated, 0 archived

Planner 5 jobs · 4 edges · 1 module 00:00

05 Packs

Bundles for the work, off until you need them.

Per-project bundles of lane roles, skills, MCP servers and gates, for coding, SEO and research. A project that has not turned a pack on gets nothing from it. Per-project bundles of lane roles, skills, MCP servers and gates. A project gets nothing from a pack it has not turned on.

NinebrainsSettings LIVE · PACKS

Settings General Gates Packs Models

Discipline packs give a project's lanes roles, skills, MCP servers and gates. Every pack is off until you enable it.

Project docs-site ▾

codingApache-2.0

Rolesbuilder, ui-builder, reviewer

MCPGitHub, Supabase, Cloudflare, all optional

Skillsnb-coding-*

Gatestests, reviewer, screenshot

Enabled for this project

seoApache-2.0

Rolesseo-lead, technical-seo, +4

MCPaeo-search, aeo-visibility, aeo-backlink

Skillsnb-seo-*

Gatesseo-evidence, reviewer

Off

researchApache-2.0

Rolesresearch-lead, researcher, fact-checker

MCPnone

Skillsnb-research-*

Gatesfact-check, reviewer

Off

Next lane launch in docs-site

✓ MCP config: brain, github

✓ Role picker: builder, ui-builder, reviewer

! supabase left out: SUPABASE_ACCESS_TOKEN missing

Settings · Packs 1 of 3 packs on 00:00

Nine agents.One repo.No collisions.

Every agent gets its own world.

One plan, handed out as it unblocks.

No agent grades its own work.

Draw the plan. Run the plan.

Bundles for the work, off until you need them.

Nine agents.
One repo.
No collisions.