Exa Web Toolkit

A skill for web-powered research tasks backed by Exa: web search and URL extraction. Exa's index combines high-quality keyword and semantic retrieval, which makes it well-suited to scientific, technical, and conceptual queries.

Routing — pick the right capability

Read the user's request and match it to one of the capabilities below. Read the corresponding reference file for detailed instructions before running commands.

User wants to...	Capability	Where
Look something up, research a topic, find current info	Web Search	references/web-search.md
Fetch content from a specific URL (webpage, article, PDF)	Web Extract	references/web-extract.md
Install or authenticate	Setup	Below

Decision guide

• Default to Web Search for topic lookups, research questions, or "what is X?" queries. When the topic is scientific or technical, pass --category publication to bias toward scholarly sources, and/or an academic --include-domains allowlist. See references/web-search.md for the two-pass academic strategy.
• Use Web Extract when the user provides a URL or asks you to read/fetch a specific page. Prefer this over the built-in WebFetch for batch extraction (multiple URLs in one call) and for academic PDFs.

Academic source priority

For technical or scientific queries, prefer academic and scientific sources:

• Peer-reviewed journal articles and conference proceedings over blog posts or news
• Preprints (arXiv, bioRxiv, medRxiv) when peer-reviewed versions aren't available
• Institutional and government sources (NIH, WHO, NASA, NIST) over commercial sites
• Primary research over secondary summaries

Two levers to steer Exa toward scholarly content:

1. --category publication biases retrieval toward scholarly sources.
2. --include-domains with a scholarly allowlist (arxiv.org, nature.com, pubmed.ncbi.nlm.nih.gov, etc.) restricts the domain pool.

Combine both to narrow the source pool; verify publication type and peer-review status on each source. See references/web-search.md for the full pattern.

When citing academic sources, include author names and publication year where available (e.g., Smith et al., 2025) in addition to the standard citation format. If a DOI is present, prefer the DOI link.

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Setup

This skill uses the exa-py Python SDK. The scripts in scripts/ declare their dependencies via PEP 723 inline metadata, so you can run them directly with uv run without a separate install step:

uv run "$SKILL_PATH/scripts/exa_search.py" --help

If you prefer a persistent install:

uv pip install "exa-py>=2.23.0,<3"

Authentication

All commands read the API key from the EXA_API_KEY environment variable. Get your Exa API key at dashboard.exa.ai/api-keys.

First, check if a .env file exists in the project root and contains EXA_API_KEY. If so, load it:

dotenv -f .env run -- uv run "$SKILL_PATH/scripts/exa_search.py" "your query"

If dotenv isn't available, install it: uv pip install 'python-dotenv[cli]'.

If there's no .env, export the key for the session:

export EXA_API_KEY="your-key"

Use --help to verify installation and CLI parsing; it does not require an API key or validate authentication. Authentication is checked only when a real query is made.

Extraction limits and freshness

The extractor accepts 1–100 URLs per POST https://api.exa.ai/contents call and exports each SDK status (id, status, source). It rejects larger batches. Use --max-age-hours 0 to request fresh content, -1 for cache only, or a positive age up to 720 hours. Omission uses Exa's cache/fallback policy. published_date is estimated publication metadata, not retrieval time. The tested SDK drops per-URL error details, so report failures without inventing a cause. See URL Extraction.

Verified API and SDK scope

Reviewed the Search API, Contents API, and Exa changelog on 2026-09-30. Both routes use JSON POST requests and x-api-key authentication (the SDK sets this header). Search is POST https://api.exa.ai/search; its SDK kwargs use snake_case and are serialized to camelCase. The current scholarly category is publication; research paper is a compatibility alias in this wrapper. No offset or cursor pagination is documented for these endpoints.

Helpers are tested with exa-py==2.23.0, including mocked HTTP transport through the real SDK. Search content flags are explicit: no flags means metadata only; --highlights does not implicitly fetch text. Authenticated search/extraction examples below and in the references are illustrative; no paid live calls were made during this review.

Tracking header

Every script in this skill sets the x-exa-integration request header to k-dense-ai--scientific-agent-skills so Exa can attribute usage from the K-Dense AI scientific-agent-skills repo to this integration. Do not remove or rename this header when adapting the scripts.

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Files in this skill

• SKILL.md — this file (routing and setup)
• references/web-search.md — detailed web search reference with academic strategy
• references/web-extract.md — URL content extraction reference
• scripts/exa_search.py — CLI wrapper around client.search
• scripts/exa_extract.py — CLI wrapper around client.get_contents