# Pay Exa from Your Agent — No API Key, One Install https://selat.ai/tutorials/pay-exa-from-your-agent _Published Aug 21, 2026_ Tags: exa api no api key, pay exa with usdc, exa x402, exa agent, exa web search api pricing, exa mpp tempo, exa pay per call, exa api without signup, ai agent web search api, exa contents endpoint --- **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](https://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): ```bash 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 →](https://selat.ai/docs/selat-plugins)**. ## 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. ```bash 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](https://www.selat.ai/docs) for `init → fund → run`. ## When to use Exa vs alternatives - **Use `/search` when you need to *find* pages.** $0.007 buys ranked, meaning-matched results when your agent doesn't yet know which URL matters. - **Use `/contents` when 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. ## Related - [Pay Tavily from your agent](/tutorials/pay-tavily-from-your-agent) - [Pay Nansen from your agent](/tutorials/pay-nansen-from-your-agent) - [Capability tutorials](/tutorials) - [SELAT CLI / docs](https://www.selat.ai/docs)