strands.vended_tools.web_fetch.web_fetch

Web fetch tool: fetch a URL and return relevant content about it.

Provides :func:make_web_fetch and the default :data:web_fetch instance. The factory’s mode parameter selects the extraction strategy at construction time:

• agentic (default): HTML is converted to markdown and passed to an analyst agent that answers prompt; the full page never enters the main agent’s context.
• markdown: HTML is converted to clean markdown with scripts, styles, and noise stripped. Use when the agent needs full pages for reasoning.

The tool delegates all networking to the httpx.AsyncClient instance provided by the operator, giving full control over transport configuration, caching, proxies, redirects, and connection pooling.

WebFetchError

class WebFetchError(ValueError)

Defined in: src/strands/vended_tools/web_fetch/web_fetch.py:32

Raised when a web fetch request fails.

make_web_fetch

def make_web_fetch(
        *,
        name: str = "web_fetch",
        description: str | None = None,
        max_bytes: int = _DEFAULT_MAX_BYTES,
        max_content_chars: int = _DEFAULT_MAX_CONTENT_CHARS,
        client: httpx.AsyncClient | None = None,
        model: Model | None = None,
        mode: Literal["markdown",
                      "agentic"] = "agentic") -> DecoratedFunctionTool

Defined in: src/strands/vended_tools/web_fetch/web_fetch.py:56

Create a web fetch tool.

Arguments:

• name - Tool name. Defaults to "web_fetch".
• description - Tool description shown to the model. Defaults to a mode-appropriate description when None.
• max_bytes - Maximum response body size in bytes. Responses larger than this are rejected without buffering the entire body. Defaults to 5 MiB.
• max_content_chars - Maximum characters of extracted content delivered to the model or analyst. Content exceeding this is truncated with a visible marker. Defaults to 50,000.
• client - Optional httpx.AsyncClient to use for requests. When provided, the tool uses it directly and will not close it. When None, a new client is created per request with follow_redirects=True and httpx’s default timeout (5s).
• model - Optional model for the analyst. Only used when mode='agentic'. Resolution order: this model, then the host agent’s model, then WebFetchError if neither is available.
• mode - Extraction mode. Defaults to agentic.

Returns:

A decorated tool that fetches a URL and extracts content according to the configured mode:

• agentic (default): HTML is converted to markdown and passed to an analyst agent that answers a prompt; the full page never enters the main agent’s context.
• markdown: HTML converted to clean markdown; other content types returned as-is.

web_fetch

Default web fetch tool (agentic mode).