@feniix/pi-exa

Exa AI extension for pi with search, fetch, research, and answer capabilities.

Features

• web_search_exa: default web search (highlights + short text snippets).
• web_fetch_exa: fetch page content by URL.
• web_search_advanced_exa: advanced search options and category filters (disabled by default).
• web_research_exa: deep-research synthesis (disabled by default).
• web_answer_exa: quick grounded answers.
• web_find_similar_exa: discover related URLs.
• exa_research_step/status/summary/reset: local, stateful research-planning tools that recommend explicit Exa retrieval calls without executing them.

Why pi-exa vs the hosted Exa MCP?

The hosted Exa MCP at https://mcp.exa.ai/mcp is a fine default for one-shot search and fetch. pi-exa exists for cases the hosted MCP cannot address by design:

• Tools the hosted MCP does not expose. web_answer_exa (Exa's /answer endpoint) and web_find_similar_exa (/findSimilar) are not advertised by the hosted MCP under any flag. If you need grounded answers with citations or "more like this" discovery, you call them directly through pi-exa.
• Local stateful planning. exa_research_step / status / summary / reset keep an in-memory research plan that survives across calls in a single pi session. A stateless remote MCP cannot offer this — there is no per-session memory to update.
• Local key custody and allowlists. Your EXA_API_KEY and enabledTools allowlist stay on the workstation. The hosted MCP requires sending your key to a third party on every request.
• Pre-flight validation. pi-exa rejects category/filter combinations Exa silently ignores (e.g., category: "people" with non-LinkedIn includeDomains), so you find out at the call site instead of in a quiet, empty result set.
• Forward-compatibility on the /research sunset. Every pi-exa tool routes through Exa's canonical endpoints — /search, /contents, /answer, /findSimilar. The hosted MCP's deep_researcher_start / deep_researcher_check tools route through the deprecated /research endpoint. When Exa enforces that sunset, those hosted tools break or lose async semantics; pi-exa's web_research_exa (which uses /search with type: "deep-reasoning") keeps working.

Capability	Hosted Exa MCP	pi-exa
web_search_exa	yes	yes
web_fetch_exa	yes	yes
web_search_advanced_exa	opt-in	opt-in
web_answer_exa (/answer)	no	yes
web_find_similar_exa (/findSimilar)	no	yes
Local research planner (exa_research_*)	no	yes
Local API key custody	no	yes
Routes deep research through /search	no	yes

Install

pi install npm:@feniix/pi-exa

For ephemeral use:

pi -e npm:@feniix/pi-exa

Configuration

You need an Exa API key from dashboard.exa.ai/api-keys for retrieval tools. The local exa_research_* planning tools work without an API key because they do not call Exa network APIs.

If you configure enabledTools, it acts as a strict allowlist. Include the exa_research_* names if you want the planner tools available with an explicit allowlist.

Recommended: environment variable

export EXA_API_KEY="your-key"

Recommended for private overrides: explicit config file

Use a private config file when you want to store an API key outside shared project settings:

{
  "apiKey": "your-key",
  "enabledTools": [
    "exa_research_step",
    "exa_research_status",
    "exa_research_summary",
    "exa_research_reset",
    "web_search_exa",
    "web_fetch_exa",
    "web_answer_exa",
    "web_find_similar_exa"
  ],
  "advancedEnabled": false,
  "researchEnabled": false
}

Then run pi with:

pi -e npm:@feniix/pi-exa -- --exa-config-file ~/.config/pi/exa.json

Shared non-secret settings

Supports standard pi settings locations:

• project: .pi/settings.json
• global: ~/.pi/agent/settings.json

Example:

{
  "pi-exa": {
    "enabledTools": [
      "exa_research_step",
      "exa_research_status",
      "exa_research_summary",
      "exa_research_reset",
      "web_search_exa",
      "web_fetch_exa",
      "web_answer_exa",
      "web_find_similar_exa"
    ],
    "advancedEnabled": false,
    "researchEnabled": false
  }
}

apiKey is accepted in settings files for compatibility, but pi-exa will warn when it is loaded there. Prefer EXA_API_KEY or --exa-config-file for secrets.

CLI flags

• --exa-api-key <key>: API key override.
• --exa-enable-advanced: enable web_search_advanced_exa.
• --exa-enable-research: enable web_research_exa.
• --exa-config-file <path>: load configuration from file.
• --exa-config <path> (deprecated alias for --exa-config-file).
• --exa-timeout-ms <ms>: default per-call timeout for Exa-backed tools (built-in 60000).
• --exa-research-timeout-ms <ms>: override for web_research_exa (built-in 180000; deep-reasoning runs longer).

The timeout bounds the JS-side wait. exa-js does not yet accept AbortSignal (exa-labs/exa-js#158), so the underlying HTTP request continues until Exa resolves it and Exa still bills for the completed call. The timeout error message states this explicitly.

Tools

exa_research_step

Records one step in an in-memory research-planning session. Params include topic, stage, note, optional criteria, sources, gaps, assumptions, nextAction, branch/revision metadata, thought_number, total_thoughts, and next_step_needed.

exa_research_status

Reports the current local planning state: topic, step count, active stage, branches, criteria coverage, source pack summary, open gaps, assumptions, and recommended next action.

exa_research_summary

Generates human-readable research planning output. Modes: brief, execution_plan, source_pack, and payload. Payload mode suggests a web_research_exa payload only; it does not run retrieval.

exa_research_reset

Clears the active in-memory planning session.

web_search_exa

Params: query (required), numResults.

Returns: formatted snippets with optional highlights and metadata (costDollars, searchTime).

web_fetch_exa

Params: urls (required array), maxCharacters, highlights, summary (query), maxAgeHours.

web_search_advanced_exa

Params:

• query (required)
• numResults (1-100, default 10)
• category: one of company, research paper, news, pdf, personal site, financial report, people
• type: canonical auto | fast | instant; legacy keyword | neural | hybrid still accepted (Exa's /search endpoint continues to accept them). Deep types (deep-reasoning | deep-lite | deep) are rejected here — use web_research_exa for those.
• Date filters: startPublishedDate, endPublishedDate (ISO dates).
• Domain filters: includeDomains, excludeDomains.
• Text filters: includeText (single-element array; only return results whose text contains this string, up to 5 words), excludeText (single-element array; exclude results whose text contains this string, up to 5 words). The Exa API accepts at most one string per filter.
• userLocation: two-letter ISO country code (e.g., US, GB, DE).
• moderation: when true, filter unsafe content.
• additionalQueries: alternative query formulations to broaden coverage.
• textMaxCharacters: max chars of page text per result (default 3000).
• contextMaxCharacters: max chars for the aggregated context string. Maps to Exa's deprecated context option and may be removed in a future Exa API release.
• Highlights: enableHighlights (gate), highlightsMaxCharacters (preferred), highlightsNumSentences (legacy fallback), highlightsQuery (overrides the search query for highlight ranking). Providing highlightsQuery or highlightsMaxCharacters implies enableHighlights: true; passing enableHighlights: false explicitly always disables highlights.
• Summary: enableSummary and/or summaryQuery (providing summaryQuery implies enableSummary: true; passing enableSummary: false explicitly always disables the summary).
• Freshness: maxAgeHours (0 = always fresh, -1 = cache-only), livecrawlTimeout (ms; capped at 60000 = 60s).
• Subpages: subpages (1-10), subpageTarget (single keyword or list of keywords used to select which subpages to crawl, e.g. 'about' or ['about', 'pricing']).

Notes:

• Deep types are rejected here. Use web_research_exa for deep-reasoning, deep-lite, or deep.
• Invalid categories return an error instead of silently falling back to an unfiltered search.
• The company and people categories do not support startPublishedDate, endPublishedDate, or excludeDomains; the people category only accepts LinkedIn domains for includeDomains. These are enforced pre-flight.
• startCrawlDate / endCrawlDate are intentionally not exposed — Exa silently ignores them as of 2026-04-15.

web_research_exa

Params include:

• query (required)
• type: deep-reasoning | deep-lite | deep
• systemPrompt
• outputSchema (type may be "object" or "text", default "text"; object mode is capped at 10 properties / depth 2 and gives per-field grounding). The default is required for synthesis to run — Exa's /search endpoint only returns an output field when an outputSchema is provided (see issue #115 and the Search API Reference for Coding Agents).
• optional additionalQueries, filters, numResults, and textMaxCharacters

web_answer_exa

Params include query (required), systemPrompt, text, and outputSchema.

web_find_similar_exa

Params include url (required), numResults, textMaxCharacters, excludeSourceDomain, date filters, and domain filters.

Integration tests

Live integration coverage is available for web_search_exa, web_fetch_exa, and web_research_exa.

These tests are:

• skipped by default
• only enabled when you opt in manually
• always skipped in CI

Run them locally with a real API key:

EXA_API_KEY=your-key npx vitest run packages/pi-exa/__tests__/integration.test.ts -- --exa-live

You can also enable them with an environment variable instead of the CLI flag:

PI_EXA_LIVE=1 EXA_API_KEY=your-key npx vitest run packages/pi-exa/__tests__/integration.test.ts

MCP server

pi-exa also exposes its tool surface as an MCP stdio server, suitable for any MCP-aware host (Claude Desktop, Claude Code, etc.). The server uses the same portable tool implementations as the Pi adapter — only the gating and credential resolution differ.

Run with:

npx pi-exa

Environment configuration

Variable	Effect
EXA_API_KEY	Exa API key. Required for retrieval tools; planner tools work without it.
EXA_ENABLE_ADVANCED	Truthy (1 / true / yes) enables web_search_advanced_exa.
EXA_ENABLE_RESEARCH	Truthy enables web_research_exa.
EXA_ENABLED_TOOLS	Comma-separated allowlist. Highest precedence. Empty/whitespace-only values emit a warning and fall through to the per-tool toggle defaults.
EXA_CONFIG_FILE	Path to a JSON config file (same shape as the CLI --exa-config-file). Use for apiKey, enabledTools, advancedEnabled, researchEnabled.
EXA_CONFIG	Deprecated alias for EXA_CONFIG_FILE. Still read; prefer EXA_CONFIG_FILE.
EXA_TIMEOUT_MS	Default per-call timeout in ms for Exa-backed tools. Built-in 60000. Underlying HTTP request continues until Exa resolves it; see exa-labs/exa-js#158.
EXA_RESEARCH_TIMEOUT_MS	Override for web_research_exa only. Built-in 180000.

Precedence

Same rules as the Pi adapter:

1. EXA_ENABLED_TOOLS (env) — strict allowlist.
2. enabledTools (config file) — strict allowlist; an empty array means "no tools".
3. EXA_ENABLE_ADVANCED / EXA_ENABLE_RESEARCH (env) or advancedEnabled / researchEnabled (config file).
4. Default: 8 tools on (4 cheap Exa + 4 planner); web_search_advanced_exa and web_research_exa hidden.

Example: Claude Desktop / claude_desktop_config.json

{
  "mcpServers": {
    "pi-exa": {
      "command": "npx",
      "args": ["-y", "@feniix/pi-exa"],
      "env": {
        "EXA_API_KEY": "your-key",
        "EXA_ENABLE_ADVANCED": "1"
      }
    }
  }
}

Example: generic mcp.json

{
  "mcpServers": {
    "pi-exa": {
      "command": "npx",
      "args": ["pi-exa"],
      "env": { "EXA_API_KEY": "your-key" }
    }
  }
}

Notes

• exa_research_* planning tools are enabled by default when no explicit enabledTools allowlist is configured, local-only, and do not require an Exa API key.
• web_search_advanced_exa and web_research_exa are opt-in and disabled by default.
• Research/tool output may include both text and details.parsedOutput depending on outputSchema.type.