web_fetch does a plain HTTP GET and extracts readable content (HTML to
markdown or text). It does not execute JavaScript. For JS-heavy sites or
login-protected pages, use the Web Browser instead.
Quick start
Enabled by default, no configuration needed:Tool parameters
string
required
URL to fetch.
http(s) only.'markdown' | 'text'
default:"markdown"
Output format after main-content extraction.
number
Truncate output to this many characters. Clamped to
tools.web.fetch.maxCharsCap.Result
web_fetch returns a closed structured result with these fields:
- Request metadata:
url,finalUrl,status,extractMode, andextractor - Optional response metadata:
contentType,title, andwarning(omitted when absent) - Wrapped content metadata:
externalContent,truncated,length,rawLength,fetchedAt,tookMs, andtext - Optional
cached: trueon a cache hit - Optional
spill: { path, chars, truncated? }when truncated content was written to a private temporary file;truncatedis present only when that file contains partial source content
length is the wrapped text length. rawLength is the extracted content length
before external-content wrapping.
How it works
1
Fetch
Sends an HTTP GET with a Chrome-like User-Agent and
Accept-Language
header. Blocks private/internal hostnames and re-checks redirects.2
Extract
Runs Readability (main-content extraction) on the HTML response.
3
Fallback (optional)
If Readability fails and a fetch provider is available, retries through
that provider (for example Firecrawl’s bot-circumvention mode).
4
Cache
Results are cached for 15 minutes (configurable) to reduce repeated
fetches of the same URL.
Progress updates
web_fetch emits a public progress line only when the fetch is still pending
after five seconds:
Config
Firecrawl fallback
If Readability extraction fails,web_fetch can fall back to
Firecrawl for bot-circumvention and better extraction:
plugins.entries.firecrawl.config.webFetch.apiKey is optional and supports SecretRef objects.
Legacy tools.web.fetch.firecrawl.* config auto-migrates to
plugins.entries.firecrawl.config.webFetch via openclaw doctor --fix.
If you configure a Firecrawl API-key SecretRef and it is unresolved with no
FIRECRAWL_API_KEY env fallback, gateway startup fails fast.Firecrawl
baseUrl overrides are locked down: hosted traffic uses
https://api.firecrawl.dev; self-hosted overrides must target private or
internal endpoints, and http:// is accepted only for those private targets.tools.web.fetch.providerselects the fetch fallback provider explicitly.- If
provideris omitted, OpenClaw auto-detects the first ready web-fetch provider from configured credentials. Non-sandboxedweb_fetchcan use installed plugins that declarecontracts.webFetchProvidersand register a matching provider at runtime. The official Firecrawl plugin provides this fallback today. - Sandboxed
web_fetchcalls allow bundled providers plus installed providers whose official npm or ClawHub provenance is verified. Today that permits the official Firecrawl plugin; third-party external fetch plugins stay excluded. - If Readability is disabled,
web_fetchskips straight to the selected provider fallback. If no provider is available, it fails closed.
Trusted env proxy
If your deployment requiresweb_fetch to go through a trusted outbound
HTTP(S) proxy, set tools.web.fetch.useTrustedEnvProxy: true.
In this mode, OpenClaw still applies hostname-based SSRF checks before sending
the request, but it lets the proxy resolve DNS instead of doing local DNS
pinning. Enable this only when the proxy is operator-controlled and enforces
outbound policy after DNS resolution.
If no HTTP(S) proxy env var is configured, or the target host is excluded by
NO_PROXY, web_fetch falls back to the normal strict path with local DNS
pinning.Limits and safety
maxCharsis clamped totools.web.fetch.maxCharsCap(default20000)- Response body is capped at
maxResponseBytes(default750000, clamped to 32000-10000000) before parsing; oversized responses are truncated with a warning - Private/internal hostnames are blocked
tools.web.fetch.ssrfPolicy.allowRfc2544BenchmarkRangeandtools.web.fetch.ssrfPolicy.allowIpv6UniqueLocalRangeare narrow opt-ins for trusted fake-IP proxy stacks; leave them unset unless your proxy owns those synthetic ranges and enforces its own destination policy- Redirects are checked and limited by
maxRedirects(default3) useTrustedEnvProxyis an explicit opt-in and should only be enabled for operator-controlled proxies that still enforce outbound policy after DNS resolutionweb_fetchis best-effort — some sites need the Web Browser
Tool profiles
If you use tool profiles or allowlists, addweb_fetch or group:web:
Related
- Web Search — search the web with multiple providers
- Web Browser — full browser automation for JS-heavy sites
- Firecrawl — Firecrawl search and scrape tools