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serving-the-api

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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.

QUICK START

How to use this skill

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Source SKILL.md: https://github.com/hashgraph-online/awesome-codex-plugins/blob/HEAD/plugins/kreuzberg-dev/plugins/plugins/crawlberg/skills/serving-the-api/SKILL.md

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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

FlagDefaultPurpose
--host0.0.0.0Address to bind to.
--port3000Port 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 + pathPurpose
POST /v1/scrapeScrape a single URL (synchronous).
POST /v1/crawlStart 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/mapDiscover URLs on a site (synchronous).
POST /v1/batch/scrapeStart an asynchronous batch-scrape job → job id.
GET /v1/batch/scrape/{id}Poll batch-scrape job status and results.
POST /v1/downloadDownload a document from a URL.

Operational:

Method + pathPurpose
GET /healthHealth check ({ status, version }).
GET /versionVersion information.
GET /openapi.jsonOpenAPI 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.