---
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"
---

# 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

| Parameter     | Type     | Description                              |
| ------------- | -------- | ---------------------------------------- |
| `url`         | `string` | URL to fetch (required, http/https only) |
| `extractMode` | `string` | `"markdown"` (default) or `"text"`       |
| `maxChars`    | `number` | Truncate output to this many chars       |

## 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,
        readability: true, // use Readability extraction
        userAgent: "Mozilla/5.0 ...", // override User-Agent
      },
    },
  },
}
```

## 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 `kaijibot 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: they must use `https://` and
  the official Firecrawl host (`api.firecrawl.dev`).
</Note>

Current runtime behavior:

- `tools.web.fetch.provider` selects the fetch fallback provider explicitly.
- If `provider` is omitted, KaijiBot auto-detects the first ready web-fetch
  provider from available credentials. Today the bundled provider is Firecrawl.
- If Readability is disabled, `web_fetch` skips straight to the selected
  provider fallback. If no provider is available, it fails closed.

## 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
- Redirects are checked and limited by `maxRedirects`
- `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
