# MeatSpace Human-in-the-loop service for AI agents. When an agent hits a subjective, high-stakes, or ambiguous decision, MeatSpace routes it to a human who picks one of 2–4 options and returns a structured result. **Live at [meatspace.run](https://meatspace.run)** ## What it does An agent posts a title, optional content (text, markdown, HTML, or an image), and 2–4 labeled choices. A human reviewer is shown the request, picks one, and the API returns the selected `id` and `label`. The agent waits via long-poll or webhook. Typical use cases: - Approval gates before destructive or irreversible actions (deploys, deletes, payments). - Subjective tie-breaks where the model is below its confidence threshold. - Tasteful judgment calls — copy choices, design preferences, ranking ties. - Escalation when an agent has run out of deterministic checks. Don't use it when the task is deterministic, automatically verifiable, or low-stakes and easily reversible. ## Three integration methods | Method | Endpoint | Best for | |---|---|---| | **REST API** | `POST /api/requests` | Any HTTP client, custom agent frameworks, server-to-server. | | **MCP** | `POST /api/mcp` (Streamable HTTP) | Claude, Claude Code, MCP-compatible clients. | | **Browser SDK** | [`/sdk/meatspace.js`](public/sdk/meatspace.js) | Agents running in a browser tab. | All three sit on the same backing API and accept the same Bearer token. ## Zero-setup self-service flow A new agent can fully onboard itself in three calls — no signup page, no approval queue, no human in the setup loop: 1. `POST /api/keys` with `{"name": "your-agent", "email": "owner@example.com"}` → returns an API key instantly. Rate-limited to 5 keys per email. 2. `POST /api/requests` with the Bearer token, your title, and choices → creates the review request. 3. `GET /api/requests/{id}/wait` → blocks until the human responds, or times out and returns `pending` with a `review_url` and `poll_url`. The same flow is available over MCP: `initialize` → `tools/list` → `provision_api_key` → `ask_human`. The `provision_api_key` and `get_service_status` tools require no auth, so a fresh MCP client can connect without credentials and bootstrap itself. ## REST quickstart Provision a key: ```bash curl -X POST https://meatspace.run/api/keys \ -H "Content-Type: application/json" \ -d '{"name": "my-agent", "email": "you@example.com"}' ``` The response includes `api_key` — shown once, save it. All subsequent calls use `Authorization: Bearer `. Create a request: ```bash curl -X POST https://meatspace.run/api/requests \ -H "Authorization: Bearer $MEATSPACE_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "agent_name": "my-agent", "title": "Ship v2.0 to production?", "content": "All tests pass. Staging looks good. 2 minor lint warnings.", "choices": [ { "id": "ship", "label": "Ship it" }, { "id": "wait", "label": "Wait for next cycle" } ], "confidence": 0.7, "consequence_of_wrong_choice": "Premature ship affects ~50k users" }' ``` Response: ```json { "success": true, "data": { "id": "uuid", "status": "pending", "review_url": "https://meatspace.run/review/uuid?token=opaque-review-token", "poll_url": "/api/requests/uuid", "expires_at": "2026-04-23T19:00:00.000Z" } } ``` Long-poll for the result: ```bash curl https://meatspace.run/api/requests/{id}/wait?timeout=25000 \ -H "Authorization: Bearer $MEATSPACE_API_KEY" ``` Returns `{ status: "completed", selected, selected_label, responded_at }` when the human responds, or `202` if still pending. Optional fields on `POST /api/requests`: `content_type` (`text` default, `markdown`, `html`, `image`), `decision_reason`, `confidence` (0–1), `consequence_of_wrong_choice`, `recommended_option`, `callback_url` (must be HTTPS and host-allowlisted), `metadata` (passed through to the webhook), `run_id`, `trace_id`, `timeout_seconds` (default 3600, max 86400). ## MCP MeatSpace implements MCP over Streamable HTTP at `https://meatspace.run/api/mcp`. The server exposes three tools: - `get_service_status` — availability and escalation guidance. No auth. - `provision_api_key` — mint a Bearer token. No auth, rate-limited. - `ask_human` — submit a decision. Requires Bearer auth. Claude Code config: ```json { "mcpServers": { "meatspace": { "type": "url", "url": "https://meatspace.run/api/mcp", "headers": { "Authorization": "Bearer " } } } } ``` `ask_human` long-polls for up to 20 seconds. If the human hasn't responded by then, the tool returns `status: "pending"` with a `review_url` (for the human) and a `poll_url` (for the agent). ## Browser SDK For agents running in browser contexts: ```html ``` Methods: `getKey()`, `createRequest()`, `pollResult()`, `waitForResult()`, `ask()` (create + wait). ## Webhooks If `callback_url` is set on the request, MeatSpace POSTs the result when the human responds: ```json { "event": "request.completed", "request_id": "uuid", "selected": "ship", "selected_label": "Ship it", "responded_at": "2026-04-23T18:10:00.000Z", "metadata": {} } ``` `callback_url` must be `https://` and the hostname must be explicitly allowlisted by the operator. If no allowlist is configured, request creation rejects callback URLs. Each delivery is signed with `X-HITL-Timestamp` and `X-HITL-Signature` headers. ## Discovery endpoints | Path | Format | Purpose | |---|---|---| | `/.well-known/mcp.json` | JSON | MCP server manifest | | `/.well-known/agent.json` | JSON | A2A Agent Card | | `/api/openapi` | JSON | OpenAPI 3.1 spec | | `/api/mcp` (GET) | JSON | MCP server info, no auth | | `/api/status` | JSON | Health check + agent guidance | | `/sdk/meatspace.js` | JavaScript | Browser SDK | | `/llms.txt` | Text | LLM-readable summary | | `/llms-full.txt` | Text | Full API documentation | | `/agents.md` | Markdown | Full integration guide | | `/sitemap.xml` | XML | Sitemap | | `/robots.txt` | Text | Crawler directives + discovery pointers | ## Errors All errors return: ```json { "success": false, "error": "Human-readable message", "code": "machine_readable_code" } ``` Common codes: `agent_name_required`, `invalid_choice_count`, `content_too_large`, `callback_url_not_allowed`, `request_create_failed`. ## Local development This repo is a Next.js 14 app deployed on Cloudflare Pages. ```bash npm install npm run dev # local dev at http://localhost:3000 npm run test # integration tests npm run build:cf # build for Cloudflare Pages npm run deploy:cf # build and deploy ``` Supabase is the system of record for keys and requests; Resend handles transactional email. ## License MIT