Migrate from Firecrawl in One Afternoon

Goal: Move a working Firecrawl integration to fastCRW in a single afternoon. This guide covers the four mechanical changes (base URL, SDK package, env var, extraction shape) plus the behavioral differences you must validate before going to production.

Time estimate: 15 minutes of code changes, 30–60 minutes of validation.

What transfers without changes

The core request shape is intentionally compatible. These work against fastCRW with no modification when you point the client at the right base URL:

• /v1/scrape — same body fields (url, formats, onlyMainContent, waitFor, maxAge, etc.)
• /v1/crawl + /v1/crawl/{id} polling
• /v1/map
• /v1/search
• Authorization: Bearer <key> header

Step 1 — Swap the base URL

Every engine call goes to https://api.fastcrw.com instead of https://api.firecrawl.dev.

curl -X POST https://api.firecrawl.dev/v1/scrape \
  -H "Authorization: Bearer $FIRECRAWL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://news.ycombinator.com",
    "formats": ["markdown"]
  }'

curl -X POST https://api.fastcrw.com/v1/scrape \
  -H "Authorization: Bearer $CRW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://news.ycombinator.com",
    "formats": ["markdown"]
  }'

Self-hosted: if you run your own crw-server, use your server's address (e.g. http://crw:3000) wherever this guide says https://api.fastcrw.com. Authentication is optional on self-hosted; disable it with [server] auth_required = false in your config.toml.

:::note{title="Keeping the Firecrawl SDK? Change one line"} You don't have to swap SDKs. Point your existing Firecrawl client at https://compat.fastcrw.com and it works. Same string in every language, no path suffix, nothing else to change:

const app = new FirecrawlApp({
  apiKey: process.env.CRW_API_KEY,
  apiUrl: "https://compat.fastcrw.com",
});

app = FirecrawlApp(
    api_key=os.environ["CRW_API_KEY"],
    api_url="https://compat.fastcrw.com",
)

That host exists because the SDKs disagree about base paths. firecrawl-py's v2 client resolves each endpoint against the base origin and drops any path you put there, while the JS client and firecrawl-py's v1 client keep it. A hostname is the one form all of them honour.

The v2 SDK is the supported drop-in; the legacy v1 SDK is compatible only for scrape.

Self-hosting? Ignore all of this and use your own address (http://crw:3000). Your engine serves every surface at the root already. :::

:::warning{title="Scheduled change: the root /v2 alias"} https://api.fastcrw.com/v2/* still answers and is what earlier versions of this guide told Python users to use. It is scheduled to close in October 2026, so that api.fastcrw.com serves only our native /v1 API.

If you are on it, move your base URL to https://compat.fastcrw.com. Nothing else changes: same shapes, same keys, same credits. Self-hosted deployments are not affected. :::

Step 2 — Swap the SDK package

Python

pip install firecrawl-py

from firecrawl import FirecrawlApp

app = FirecrawlApp(api_key="fc-...")

result = app.scrape_url(
    "https://news.ycombinator.com",
    params={"formats": ["markdown"]},
)
print(result["markdown"][:500])

pip install crw

from crw import CrwClient

client = CrwClient()  # reads CRW_API_KEY from env

result = client.scrape(
    "https://news.ycombinator.com",
    formats=["markdown"],
)
print(result["markdown"][:500])

TypeScript / JavaScript

npm install @mendable/firecrawl-js

import FirecrawlApp from "@mendable/firecrawl-js";

const app = new FirecrawlApp({ apiKey: "fc-..." });

const result = await app.scrapeUrl("https://news.ycombinator.com", {
  formats: ["markdown"],
});
console.log(result.markdown?.slice(0, 500));

npm install crw-sdk

import { CrwClient } from "crw-sdk";

const client = new CrwClient({ apiKey: process.env.CRW_API_KEY });

const result = await client.scrape("https://news.ycombinator.com", {
  formats: ["markdown"],
});
console.log(result.markdown?.slice(0, 500));

Step 3 — Rename the environment variable

Shell (.env or export):

# remove
# export FIRECRAWL_API_KEY=fc-...

# add
export CRW_API_KEY=crw-...

Both SDKs read the variable automatically. No code change is needed once the env var is in place.

Step 4 — Port LLM extraction

Firecrawl exposes a standalone /v1/extract route. fastCRW supports both styles: single-URL extraction runs through /v1/scrape with formats: ["json"] and a jsonSchema (response field data.json), and multi-URL extraction has a native async POST /v1/extract (URLs + prompt/schema) that returns a per-URL results array via GET /v1/extract/{id}.

Multi-URL extraction: send { "urls": [...], "prompt"/"schema": ... } to /v1/extract, then poll /v1/extract/{id} for results (one { url, status, data, error } per URL).

from firecrawl import FirecrawlApp

app = FirecrawlApp(api_key="fc-...")

schema = {
    "type": "object",
    "properties": {
        "title": {"type": "string"},
        "price": {"type": "string"},
    },
    "required": ["title", "price"],
}

result = app.extract(
    ["https://example.com/product"],
    {"schema": schema},
)
print(result)

from crw import CrwClient

client = CrwClient()  # reads CRW_API_KEY from env

schema = {
    "type": "object",
    "properties": {
        "title": {"type": "string"},
        "price": {"type": "string"},
    },
    "required": ["title", "price"],
}

# Pass json_schema — the SDK adds "json" to formats automatically
result = client.scrape(
    "https://example.com/product",
    json_schema=schema,
)
print(result["json"])

import FirecrawlApp from "@mendable/firecrawl-js";

const app = new FirecrawlApp({ apiKey: "fc-..." });

const schema = {
  type: "object",
  properties: {
    title: { type: "string" },
    price: { type: "string" },
  },
  required: ["title", "price"],
};

const result = await app.extract(["https://example.com/product"], {
  schema,
});
console.log(result.data);

import { CrwClient } from "crw-sdk";

const client = new CrwClient({ apiKey: process.env.CRW_API_KEY });

const schema = {
  type: "object",
  properties: {
    title: { type: "string" },
    price: { type: "string" },
  },
  required: ["title", "price"],
};

// Pass jsonSchema — the SDK adds "json" to formats automatically
const result = await client.scrape("https://example.com/product", {
  jsonSchema: schema,
});
console.log(result.json);

Behavioral differences to validate

The following table lists the gaps documented in the capability matrix. Validate each that applies to your workload before switching production traffic.

5-minute verification checklist

Run these five commands against a real URL from your workload after making the changes above. Use a URL you can manually inspect in your browser.

1. Smoke test — basic scrape

curl -s -X POST https://api.fastcrw.com/v1/scrape \
  -H "Authorization: Bearer $CRW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://news.ycombinator.com", "formats": ["markdown"]}' \
  | python3 -m json.tool | head -30

Expected: "success": true, "markdown" field with real content.

2. Crawl smoke test

curl -s -X POST https://api.fastcrw.com/v1/crawl \
  -H "Authorization: Bearer $CRW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com", "maxDepth": 1, "maxPages": 3}' \
  | python3 -m json.tool

Expected: {"success": true, "id": "<job-id>"}. Poll GET /v1/crawl/{id} until "status": "completed".

3. Map smoke test

curl -s -X POST https://api.fastcrw.com/v1/map \
  -H "Authorization: Bearer $CRW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com", "maxDepth": 1}' \
  | python3 -m json.tool | head -20

Expected: "links": [...] with discovered URLs.

4. Search smoke test

curl -s -X POST https://api.fastcrw.com/v1/search \
  -H "Authorization: Bearer $CRW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "fastcrw web scraper", "limit": 3}' \
  | python3 -m json.tool | head -30

Expected: "data": [...] with search results. (Against a self-hosted engine the same call returns "data": {"results": [...]} — see Response shapes.)

5. SDK round-trip (Python)

import os
from crw import CrwClient

client = CrwClient()  # CRW_API_KEY must be set

# Basic scrape
result = client.scrape("https://example.com", formats=["markdown"])
assert result.get("markdown"), "markdown field is empty"
print("scrape: OK")

# Map
links = client.map("https://example.com", max_depth=1)
assert isinstance(links, list) and len(links) > 0, "map returned no links"
print(f"map: OK ({len(links)} links)")

print("All checks passed — safe to promote to production.")

Feature-detect the engine

Use GET /v1/capabilities to confirm what the target engine supports before sending calls that depend on optional features (LLM extraction, file parsing, search):

curl -s https://api.fastcrw.com/v1/capabilities \
  -H "Authorization: Bearer $CRW_API_KEY" \
  | python3 -m json.tool

The response lists llm, search, documents.parsers, and formats so your code can branch instead of assuming.

What is not in scope

The following Firecrawl Cloud capabilities have no equivalent in fastCRW and are not planned:

• /v1/deep-research (Spark model pipeline)
• /v1/agent (AI agent sessions)
• Fire-engine proprietary anti-bot layer

Bring-your-own-proxy IS supported on a self-hosted instance: set a pool in [proxy], or pass proxy on the scrape body. See Proxies.

For any capability not in the matrix above, check the capability matrix which is the authoritative reference.