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openclaw/docs/tools/web-fetch.md
2026-05-03 22:35:30 +01:00

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---
summary: "web_fetch tool -- HTTP fetch with readable content extraction"
read_when:
- You want to fetch a URL and extract readable content
- You need to configure web_fetch or its Firecrawl fallback
- You want to understand web_fetch limits and caching
title: "Web fetch"
sidebarTitle: "Web Fetch"
---
The `web_fetch` tool 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](/tools/browser) instead.
## Quick start
`web_fetch` is **enabled by default** -- no configuration needed. The agent can
call it immediately:
```javascript
await web_fetch({ url: "https://example.com/article" });
```
## Tool parameters
<ParamField path="url" type="string" required>
URL to fetch. `http(s)` only.
</ParamField>
<ParamField path="extractMode" type="'markdown' | 'text'" default="markdown">
Output format after main-content extraction.
</ParamField>
<ParamField path="maxChars" type="number">
Truncate output to this many characters.
</ParamField>
## How it works
<Steps>
<Step title="Fetch">
Sends an HTTP GET with a Chrome-like User-Agent and `Accept-Language`
header. Blocks private/internal hostnames and re-checks redirects.
</Step>
<Step title="Extract">
Runs Readability (main-content extraction) on the HTML response.
</Step>
<Step title="Fallback (optional)">
If Readability fails and Firecrawl is configured, retries through the
Firecrawl API with bot-circumvention mode.
</Step>
<Step title="Cache">
Results are cached for 15 minutes (configurable) to reduce repeated
fetches of the same URL.
</Step>
</Steps>
## Config
```json5
{
tools: {
web: {
fetch: {
enabled: true, // default: true
provider: "firecrawl", // optional; omit for auto-detect
maxChars: 50000, // max output chars
maxCharsCap: 50000, // hard cap for maxChars param
maxResponseBytes: 2000000, // max download size before truncation
timeoutSeconds: 30,
cacheTtlMinutes: 15,
maxRedirects: 3,
useTrustedEnvProxy: false, // let a trusted HTTP(S) env proxy resolve DNS
readability: true, // use Readability extraction
userAgent: "Mozilla/5.0 ...", // override User-Agent
ssrfPolicy: {
allowRfc2544BenchmarkRange: true, // opt-in for trusted fake-IP proxies using 198.18.0.0/15
allowIpv6UniqueLocalRange: true, // opt-in for trusted fake-IP proxies using fc00::/7
},
},
},
},
}
```
## Firecrawl fallback
If Readability extraction fails, `web_fetch` can fall back to
[Firecrawl](/tools/firecrawl) for bot-circumvention and better extraction:
```json5
{
tools: {
web: {
fetch: {
provider: "firecrawl", // optional; omit for auto-detect from available credentials
},
},
},
plugins: {
entries: {
firecrawl: {
enabled: true,
config: {
webFetch: {
apiKey: "fc-...", // optional if FIRECRAWL_API_KEY is set
baseUrl: "https://api.firecrawl.dev",
onlyMainContent: true,
maxAgeMs: 86400000, // cache duration (1 day)
timeoutSeconds: 60,
},
},
},
},
},
}
```
`plugins.entries.firecrawl.config.webFetch.apiKey` supports SecretRef objects.
Legacy `tools.web.fetch.firecrawl.*` config is auto-migrated by `openclaw doctor --fix`.
<Note>
If Firecrawl is enabled and its SecretRef is unresolved with no
`FIRECRAWL_API_KEY` env fallback, gateway startup fails fast.
</Note>
<Note>
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.
</Note>
Current runtime behavior:
- `tools.web.fetch.provider` selects the fetch fallback provider explicitly.
- If `provider` is omitted, OpenClaw auto-detects the first ready web-fetch
provider from available credentials. Non-sandboxed `web_fetch` can use
installed plugins that declare `contracts.webFetchProviders` and register a
matching provider at runtime. Today the bundled provider is Firecrawl.
- Sandboxed `web_fetch` calls stay limited to bundled providers.
- If Readability is disabled, `web_fetch` skips straight to the selected
provider fallback. If no provider is available, it fails closed.
## Trusted Env Proxy
If your deployment requires `web_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.
<Note>
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.
</Note>
## Limits and safety
- `maxChars` is clamped to `tools.web.fetch.maxCharsCap`
- Response body is capped at `maxResponseBytes` before parsing; oversized
responses are truncated with a warning
- Private/internal hostnames are blocked
- `tools.web.fetch.ssrfPolicy.allowRfc2544BenchmarkRange` and
`tools.web.fetch.ssrfPolicy.allowIpv6UniqueLocalRange` are 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`
- `useTrustedEnvProxy` is an explicit opt-in and should only be enabled for
operator-controlled proxies that still enforce outbound policy after DNS
resolution
- `web_fetch` is best-effort -- some sites need the [Web Browser](/tools/browser)
## Tool profiles
If you use tool profiles or allowlists, add `web_fetch` or `group:web`:
```json5
{
tools: {
allow: ["web_fetch"],
// or: allow: ["group:web"] (includes web_fetch, web_search, and x_search)
},
}
```
## Related
- [Web Search](/tools/web) -- search the web with multiple providers
- [Web Browser](/tools/browser) -- full browser automation for JS-heavy sites
- [Firecrawl](/tools/firecrawl) -- Firecrawl search and scrape tools