Rivalatch — Shared ship door for rival AI agents

Rival agents.
One gate.

Rivalatch is the doorway rival AI agents knock on before a ship moves. Not a sandbox console. Not a CI dashboard. Not a marketplace. One Spec-locked surface — first caller held, second incoming.

Public name Rivalatch. Code, env, and packages still say VibeGate (VIBEGATE_*, vibegate-*, X-VibeGate-Signature-256).

HTTP gate.run · MCP for Cursor / Claude Code / Codex / Grok Build · zero new Spec fields

How a knock works

Same idempotency_key. Different stories collide as public held | incoming.

202lodged

Accepted

New key. First caller gets in. Job is queued on the shared door — the held story.

# first knock
POST /v1/gate/run
→ 202 { job_id, state }

200recalled

Replay

Same key, same payload. Idempotent return of the existing job — no second ship.

# exact replay
POST /v1/gate/run
→ 200 { job_id, state }

409occupied · contested

Conflict

Same key, different payload. Rival knock. Public detail shows held vs incoming — never crown private fields.

# rival knock
POST /v1/gate/run
→ 409 held | incoming

held caller A Lodged202

incoming caller B Conflict409

MCP for Cursor, Claude Code, Codex & Grok Build

Stdio MCP (vibegate-mcp) — same three tools as HTTP. Shared door for rival agents, not a sandbox.

Three tools

MCP · HTTP

Tool	HTTP
`gate.run`	`POST /v1/gate/run`
`gate.status`	`GET /v1/gate/status/{job_id}`
`gate.get_result`	`GET /v1/gate/results/{job_id}`

Auth: VIBEGATE_API_KEY → X-Api-Key. Entry: vibegate-mcp or python -m vibegate_ship.mcp_stdio. No MCP-over-HTTP in MVP v0 — REST stays at /v1/gate/*.

# Cursor · .cursor/mcp.json
"command": "/ABS/PATH/TO/vibegate-mcp"
# Claude Code
claude mcp add --transport stdio vibegate -- vibegate-mcp
# Codex · ~/.codex/config.toml
[mcp_servers.vibegate]
command = "/ABS/PATH/TO/vibegate-mcp"
# Grok Build
grok mcp add vibegate -- vibegate-mcp

Full paste cards: MCP.md · agent body: AGENT.md · mobile: MOBILE_KNOCKER.md

Cursorstdio · .cursor/mcp.json
Claude Codestdio · claude mcp add
Codexstdio · config.toml
Grok Buildstdio · grok mcp add

Door words

Each door state has one glyph and one color. The shape alone is enough, so it reads in grayscale too. Wire codes are unchanged; the words are prose.

202lodged

Lodged

New idempotency key. The door takes the job and returns { job_id, state }.

running

Running

Checks run in the sandbox. gate.status reports queued or running until terminal.

pass

Pass

Receipt sealed with verdict: pass. fail_class is null.

fail

Fail

Receipt with verdict: fail and a class saying why, with repro to replay it.

fail_class: assert · build · infra …