Web Search and Web Fetch use the same server-tool loop but solve different tasks:

Tool	Input	Output
`bitrouter:web_search`	Search query	Normalized result list or backend answer
`bitrouter:web_fetch`	URL	Normalized page content

Both are off by default. The deployment configures ordered backends, and each request explicitly declares the tool.

Configure backends

server_tools:
  web_search:
    max_results: 5
    backends:
      - kind: parallel
      - kind: exa
      - kind: firecrawl
      - kind: tavily

  web_fetch:
    max_content_tokens: 4000
    backends:
      - kind: exa
      - kind: firecrawl
      - kind: tavily

Each HTTP backend reads an explicit api_key or its conventional environment variable:

Backend	Search	Fetch	Environment variable
Parallel	Yes	No	`PARALLEL_API_KEY`
Exa	Yes	Yes	`EXA_API_KEY`
Firecrawl	Yes	Yes	`FIRECRAWL_API_KEY`
Tavily	Yes	Yes	`TAVILY_API_KEY`

Backends are tried in config order. Entries with no resolvable key are skipped; if none resolve, that tool remains disabled and the daemon logs why.

Web Search also supports a native backend that runs a search-capable model with its provider-native search tool. That is a nested model call rather than an HTTP search API.

Web Search

{
  "type": "bitrouter:web_search",
  "args": {"backend": "exa", "max_results": 3}
}

The parent model calls web_search with a query. A declaration may pin one configured backend and lower the result cap. A bare or foreign-namespaced web_search remains a provider-native tool; only the explicit bitrouter: namespace selects BitRouter's implementation.

Web Fetch

{
  "type": "bitrouter:web_fetch",
  "args": {"backend": "firecrawl", "max_content_tokens": 1500}
}

The parent calls web_fetch with a URL. max_content_tokens resolves from deployment to declaration and may only be lowered. Exa, Firecrawl, or Tavily fetch the address on their infrastructure; BitRouter sends the URL to the chosen extraction API instead of dereferencing it directly.

Operational boundaries

Search and fetch content is untrusted model input; keep prompt-injection defenses in the calling workflow.
Backend requests consume external quota and may leave your network.
Tool results are bounded by the server-tool loop and appear in request telemetry when export is enabled.
Backend pinning chooses an already configured implementation; it does not supply or reveal a credential.

Server tools

Understand activation, loop bounds, and authorization.

Observability

Inspect nested calls and exported traces.

Web tools