/crawlberg-serving-the-api

description: Use when the user wants a long-running HTTP service for scrape/crawl/map instead of one-shot CLI calls or the MCP server — for example wiring crawlberg into other apps over REST. Covers `crawlberg serve`, the Firecrawl-v1-compatible endpoints, `--host`/`--port`, and when to prefer it.
name: crawlberg-serving-the-api

<!-- AI-RULEZ :: GENERATED FILE — DO NOT EDIT Content-Hash: blake3:1985fa0ec5929f7949a6ffe17c9473bfef3221180eabd504f8ca01e3821d8618 Source-Hash: blake3:c646c26d88f919b6848be2422454cabae94e9cbdfefeef3d4beecb56021295a0 Schema-Version: v1 -->

Serving the API

`crawlberg serve` starts a long-running REST API server exposing the crawl engine over HTTP. The endpoints are Firecrawl v1-compatible, so existing Firecrawl clients and SDKs can point at a local crawlberg instance.

This subcommand requires the binary to be built with the optional `api` feature (non-default). The Homebrew tap is built with all features, so `serve` is available there; a from-source build needs `cargo install crawlberg-cli --features api` (or `--features all`) to include it.

Quick recipe

crawlberg serve --host 127.0.0.1 --port 3000

It logs `Starting REST API server on <host>:<port>` to stderr and blocks until terminated. Hit `GET /health` to confirm it is up.

Flags

| Flag | Default | Purpose | | -------- | --------- | -------------------------------- | | `--host` | `0.0.0.0` | Address to bind to. | | `--port` | `3000` | Port to listen on. |

`serve` does not take the per-request crawl flags — it boots with the default `CrawlConfig` and accepts per-request options in each HTTP request body.

Endpoints

Firecrawl v1 surface:

| Method + path | Purpose | | ------------------------- | ---------------------------------------------------- | | `POST /v1/scrape` | Scrape a single URL (synchronous). | | `POST /v1/crawl` | Start an asynchronous crawl job → returns a job `id`. | | `GET /v1/crawl/{id}` | Poll crawl job status and collect results. | | `DELETE /v1/crawl/{id}` | Cancel a running crawl job. | | `POST /v1/map` | Discover URLs on a site (synchronous). | | `POST /v1/batch/scrape` | Start an asynchronous batch-scrape job → job `id`. | | `GET /v1/batch/scrape/{id}` | Poll batch-scrape job status and results. | | `POST /v1/download` | Download a document from a URL. |

Operational:

| Method + path | Purpose | | ----------------- | ---------------------------------------- | | `GET /health` | Health check (`{ status, version }`). | | `GET /version` | Version information. | | `GET /openapi.json` | OpenAPI schema for the whole surface. |

Request bodies use `camelCase` fields. Scrape/crawl/map mirror the CLI: `url`, `formats`, `onlyMainContent`, `includeTags`/`excludeTags`, `timeout` for scrape; `url`, `maxDepth`, `maxPages`, `includePaths`/`excludePaths` for crawl; `url`, `limit`, `search` for map. Responses wrap data as `{ success, data | error }`; async jobs return `{ success, id }` and are polled for `{ status, total, completed, data, error }`.

Examples

Scrape via HTTP

curl -s http://127.0.0.1:3000/v1/scrape \
  -H 'content-type: application/json' \
  -d '{"url":"https://example.com","formats":["markdown"]}' | jq '.data'

Start a crawl job and poll it

id=$(curl -s http://127.0.0.1:3000/v1/crawl \
  -H 'content-type: application/json' \
  -d '{"url":"https://example.com","maxDepth":2,"maxPages":100}' | jq -r '.id')

curl -s "http://127.0.0.1:3000/v1/crawl/$id" | jq '{status,completed,total}'

Map URLs

curl -s http://127.0.0.1:3000/v1/map \
  -H 'content-type: application/json' \
  -d '{"url":"https://example.com","limit":500,"search":"docs"}' | jq '.data'

Operational notes

• The server accepts CORS from any origin and ships **no built-in

authentication** — do not expose it on a public interface. Bind to `127.0.0.1` for local use, or put it behind a reverse proxy / gateway that enforces auth and rate limiting before exposing it more widely.

• Request bodies are capped at 10 MB and each request times out after 5

minutes.

• Crawl and batch-scrape are asynchronous: the POST returns a job `id`

immediately and you poll the `{id}` endpoint until `status` is `completed`, `failed`, or `cancelled`.

When to run serve vs. CLI vs. MCP

• **CLI** (`scrape`/`crawl`/`map`/`interact`) — one-shot jobs, shell pipelines,

scripting. No long-running process.

• **MCP** (`crawlberg mcp`) — driving the crawler from an AI agent harness

(Claude Code, Codex, Cursor, Gemini, opencode). Auto-registered by this plugin; prefer it inside an agent.

• **serve** (`crawlberg serve`) — a persistent HTTP service for other

applications or non-agent clients that speak REST, or when you want Firecrawl-v1 compatibility. Choose it when many callers need the crawler over the network rather than one agent or one shell.