Coding Agent API

The Coding Agent API exposes the same OpenCode + E2B runtime as Builder for automation: CI bots, internal tools, and agents that already use Critique crt_ keys.

Marketing overview and copy-paste examples also live at /coding-agent-api.

Authentication

Keys act as your Critique user. The repository must already be on a GitHub App installation you control.

Endpoints

Create run body

Example — managed billing

curl https://critique.sh/api/v1/coding-agent/runs \
  -H "Authorization: Bearer crt_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "repository": "acme/web",
    "prompt": "Add Stripe webhook signature verification and tests.",
    "modelId": "anthropic/claude-sonnet-4.6",
    "billing": { "mode": "managed" },
    "publish": { "mode": "draft_pr" },
    "validationMode": "tests"
  }'

Example — OpenRouter billing

Pass your OpenRouter key in the body; Critique runs the sandbox and OpenRouter bills tokens on your account.

curl https://critique.sh/api/v1/coding-agent/runs \
  -H "Authorization: Bearer crt_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "repository": "acme/web",
    "prompt": "Migrate the settings page to server actions.",
    "modelId": "openai/gpt-5.4",
    "billing": {
      "mode": "openrouter",
      "openRouterApiKey": "sk-or-v1-..."
    },
    "publish": {
      "mode": "draft_pr",
      "branch": "critique-agent/settings-server-actions"
    }
  }'

Follow-up messages (persistent session)

When a run finishes its first turn, status becomes idle and the E2B sandbox + OpenCode session stay warm until sessionExpiresAt. Send another prompt on the same run id — no new sandbox, no chained summary prompt.

curl https://critique.sh/api/v1/coding-agent/runs/RUN_ID/messages \
  -H "Authorization: Bearer crt_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Add a regression test for expired signatures.",
    "publish": { "mode": "draft_pr" }
  }'

Close the session explicitly (kills the sandbox) with { "endSession": true }.

If the session expired or the run predates persistent sessions, the API falls back to a chained new run (prior context in the prompt, new sandbox).

Live event stream (SSE)

curl -N "https://critique.sh/api/v1/coding-agent/runs/RUN_ID/stream?after=EVENT_ID" \
  -H "Authorization: Bearer crt_YOUR_KEY"

Events: builder.event (OpenCode activity rows), run.status when the turn reaches idle, completed, or failed.

Response shape

Completed runs return (among other fields):

• status — queued, running, idle (session warm), completed, failed
• sessionActive — true when idle and inside sessionExpiresAt
• turnCount — number of user turns on this run
• repository — full name and ids
• modelId — selected model
• summary — assistant-facing completion text
• changedPaths, diffStats — when a patch exists
• patch — when requested with ?patch=1
• events — OpenCode activity when requested with ?events=1
• draftPullRequest — GitHub metadata when publish.mode was draft_pr

Poll GET /api/v1/coding-agent/runs/{id}?patch=1 until status is terminal.

Billing modes

Managed mode uses the same catalog as Builder and Remedy. See Billing & credits.

Runtime

• Engine: OpenCode headless server inside an ephemeral E2B sandbox
• Isolation: Repo clone at the requested ref; sandbox stays alive between turns while idle, then until expiry or endSession
• Output: No automatic push unless publish.mode is draft_pr and GitHub permissions allow it

This API is not the same as BYOA review-run queueing (Cursor / Claude / Codex on a completed PR review). Use BYOA when you want Critique to hand off a fix blueprint from a review; use the Coding Agent API when you want a general coding task on a repo.

Related

• Coding Agent API product page — comparison table, FAQ, pricing for “best/cheapest cloud coding agent API”, cookbooks, and signed-in crt_ key generation
• Chat & workspace — Builder UI at /builder and /workspace?mode=build
• Connections & Platform API — MCP, passports, crt_ scopes
• BYOK — OpenRouter for review/chat, optional per-run key here