Exa is an AI-native web search API: neural and keyword search over live web pages, plus content extraction that returns clean page text, highlights, and AI-generated summaries. Your agent can call it per request, with no API key and no signup — the endpoint answers 402, the agent pays USDC from the user's Circle Agent Wallet, and the result comes back in the same run. SELAT never holds keys or funds.
What Exa does
Exa searches the web by meaning rather than keyword match and returns results already shaped for a model to read: ranked URLs, titles, published dates, authors, full page text, highlights, and summaries. It exists to ground LLMs and agents on live web data.
- Semantic web search — find relevant pages by meaning, not exact-match terms.
- Clean content retrieval — pull readable page text from a URL or an Exa document ID.
- Highlights and AI summaries — condensed page content for grounding a model.
- News, company research, and fact-checking — recent dated results, sourced pages for a named entity, and the page a claim actually came from.
Full API reference: docs.exa.ai.
What it costs
Exa lists 2 endpoints in the catalog, both of them priced, and both payable on every chain Exa quotes.
| Endpoint | What it returns | Price | Rail |
|---|---|---|---|
POST /search | Ranked web results optimized for AI agents | $0.007 | all 3 rails |
POST /contents | Clean page content from URLs or Exa document IDs | $0.001 | all 3 rails |
Catalog prices run from $0.001 to $0.007 per call. /contents costs a seventh of /search, so a retrieval-heavy loop stays cheap per page.
Where Exa is payable
Exa is payable on Base, Solana, and Tempo; the agent does not pick.
Install SELAT in your agent
SELAT installs once per agent runtime — no per-service setup, no API key. Quickest path (Claude Code):
claude plugin marketplace add SELAT-AI/selat-plugins
claude plugin install selat@selat-plugins
Using Codex, Cursor, Gemini CLI, OpenClaw, Hermes, or a plain terminal? Follow the canonical, always-current install guide: Install SELAT →.
Pay Exa from your agent
selat search is free: hosted discovery returns ranked, live-priced candidates and does not spend. selat run spends — it discovers, quotes, and pays USDC from the user's Circle Agent Wallet. selat run --dry-run quotes without paying. SELAT never holds keys or funds.
selat search "search the web for recent papers on agentic payments" # free — ranked, live-priced
selat run "search the web for recent papers on agentic payments" --dry-run # quotes without paying
selat run "search the web for recent papers on agentic payments" # spends: discover → quote → pay USDC
Fund path: init → fund → run. Fund Circle Gateway, then pay USDC from the user's Circle Agent Wallet.
See the SELAT CLI / docs for init → fund → run.
When to use Exa vs alternatives
- Use
/searchwhen you need to find pages. $0.007 buys ranked, meaning-matched results when your agent doesn't yet know which URL matters. - Use
/contentswhen you already have the URL. At $0.001, extraction costs a seventh of search — don't pay search prices to read a page you already found. - Use Exa when the answer has to be current. A model's weights are stale by definition; Exa's job is live web grounding.
- Skip Exa when the model already knows. A paid call for something answerable from context is money spent on nothing.
FAQ
Do I need an Exa API key to use Exa from an agent?
No. The endpoint answers HTTP 402 with a payment instruction, your agent pays USDC from the user's Circle Agent Wallet, and the retry returns the data. No signup, no dashboard, no key to rotate. SELAT never holds keys or funds.
How much does one Exa API call cost?
POST /search quotes $0.007 per call and POST /contents quotes $0.001. A loop that searches once and reads five pages runs about $0.012.
Which chain does Exa settle on?
Exa is payable on Base, Solana, and Tempo; the agent does not pick.
What's the difference between Exa /search and /contents?
/search finds pages by meaning and returns ranked results. /contents takes URLs or Exa document IDs you already have and returns clean text, highlights, and summaries. Most loops call /search once and /contents several times.
Is Exa's /contents endpoint free?
Not as a documented tier — budget $0.001 per call. One /contents listing does carry a $0 quote with no amount attached.
Can my agent pay Exa in USDC?
Yes. Pay USDC from the user's Circle Agent Wallet. Your agent pays whatever asset the quote names, without choosing.
Can I cap what my agent spends on Exa in one run?
Yes. You set a per-call ceiling and a session budget, and you can freeze the wallet. With a $0.001–$0.007 spread the ceiling matters less here than the session budget — the risk on Exa is call volume, not any single call.
How do I call Exa from my agent?
Install the SELAT plugin in Claude Code, Codex, Cursor, Gemini CLI, OpenClaw, or Hermes, then ask for the web context you need — the agent finds Exa in the catalog and selat run pays for the call in the same session. You write the intent; the agent does not pick the chain.