Pi Web Search

A Pi extension that gives the agent two tools for working with the open web:

1. web_search for querying multiple search providers with automatic fallback.
2. web_fetch for reading pages as clean markdown.

The extension manages three search backends (Brave, Tavily, Exa) behind a single interface. It selects the best available provider for each request based on the capabilities the request needs, falls back on transient failures, and tells the agent when a result has been degraded. Page fetching is backed by Jina Reader.

Install

pi install npm:@counterposition/pi-web-search

Tools

web_search

Returns titles, URLs, snippets, and dates. Parameters:

Parameter	Description
query	Search query.
depth	basic (default) returns snippets. thorough uses content-capable search and may include one inline excerpt.
freshness	Optional recency filter: day, week, month, or year.
domains	Optional allowlist of bare hostnames to restrict results (max 10).
max_results	1--20, default 5.

web_fetch

Fetches a URL through Jina Reader and returns the page content as markdown. Long pages are paginated: use offset and max_chars to page through content in 8,000-character windows by default (up to 20,000 per call). Fetched pages are cached in an LRU cache (20 entries, 5-minute TTL) so repeated reads of the same URL within a session are free.

Providers

Each search provider has different capabilities. The extension routes requests to the provider best suited for the job:

Provider	Capabilities	Best for
Brave	search, freshness	Fast basic queries; time-sensitive searches
Tavily	search, content, semantic, freshness, domain filter, dates	Thorough searches; domain-scoped research
Exa	search, content, semantic, freshness, domain filter, dates	Thorough searches; domain-scoped research
Jina	page fetch	Reading full pages as markdown

How provider resolution works: When a search comes in, the extension ranks available providers by how well they match the request. A thorough search needs the content capability, so Tavily and Exa are preferred. A basic search with a freshness filter prefers Brave. If the top-ranked provider fails transiently (network error, rate limit), the next provider in the ranking is tried. If no provider can serve the requested depth, a thorough search degrades to basic and the agent is told.

You can override the automatic ranking by setting a preferred provider per depth level (see Settings below).

Configuration

API keys

Set at least one search provider key. Keys can be set as environment variables or in the global Pi settings file (~/.pi/agent/settings.json under webSearch.apiKeys). Project-level API keys are intentionally ignored.

Variable	Provider	Required
BRAVE_API_KEY	Brave Search	For basic/fresh searches
TAVILY_API_KEY	Tavily	For thorough searches
EXA_API_KEY	Exa	For thorough searches
JINA_API_KEY	Jina Reader	Optional (works without a key at lower rate limits)

Recommended minimum: BRAVE_API_KEY plus either TAVILY_API_KEY or EXA_API_KEY. Brave covers basic and freshness-filtered searches. Tavily or Exa covers thorough searches that need content-capable discovery. With only one provider, thorough searches may silently degrade to basic.

Settings

Optional overrides in settings.json (global or project-level) under webSearch:

{
  "webSearch": {
    "preferredBasicProvider": "brave",
    "preferredThoroughProvider": "tavily"
  }
}

When set, the preferred provider is tried first for that depth level before falling back to the default ranking.

Security

The extension takes two precautions around untrusted web content:

• SSRF protection. web_fetch validates URLs before fetching. Private and reserved IP ranges (RFC 1918, link-local, loopback), cloud metadata endpoints, and .local/.internal hostnames are all blocked. Only http and https schemes are allowed; embedded credentials are rejected.
• Prompt injection mitigation. The extension appends a system prompt instructing the agent to treat web content as untrusted data, not as instructions to follow.