# expand.ai Documentation

- [Authentication & API keys](https://review.expand.ai/docs/authentication): Sign in for the CLI and local tools, use an API key everywhere else, and send it the right way for each surface.
- [CLI commands](https://review.expand.ai/docs/cli-commands): Every expandai command, argument, flag, and default. Fetch a page, highlight it, read its Appendix, sign in, set up a coding agent, and clean up.
- [CLI, Skill & hooks](https://review.expand.ai/docs/cli-skill-and-hooks): What installing the Expand CLI adds on top of the hosted MCP server. Terminal fetches, the Expand Skill, the OpenCode web-fetch hook, and proxy support.
- [Docs for agents](https://review.expand.ai/docs/docs-for-agents): Let an agent set Expand up from start.md, and give an agent Expand's docs as Markdown, one page or all of it.
- [Errors & retries](https://review.expand.ai/docs/errors-and-retries): How to tell an Expand failure from a dead URL, which errors to retry, and what you are charged for.
- [FAQ](https://review.expand.ai/docs/faq): Short answers to common questions about Fetch, agents, Highlights, billing, tiers, and the docs themselves, each with a link to the page that has the detail.
- [Get started with Expand](https://review.expand.ai/docs): Send a page URL and get Markdown with tables and icons intact, plus the page's hidden JSON as State JSON. Each Markdown line links to its source. Set up your agent, or run your first Fetch from the CLI, the TypeScript SDK, or the API.
- [Limits](https://review.expand.ai/docs/limits): How many captures you can run at once, how long a request can take, and how large a page, file, batch, or crawl can be.
- [Connect your agent (MCP)](https://review.expand.ai/docs/mcp-server): Add Expand's hosted MCP server to Claude Code, Codex, Cursor, fx, or any MCP client. Nothing to install, and you sign in through the browser.
- [MCP tools & resources](https://review.expand.ai/docs/mcp-tools-and-resources): The four tools the Expand MCP server gives an agent, with every parameter, default, and result field, plus the two documentation resources.
- [Pricing & Usage](https://review.expand.ai/docs/pricing-and-usage): What each operation costs in credits, how credits are bought and spent, what is never charged, and how browser concurrency is priced.
- [Python SDK](https://review.expand.ai/docs/python-sdk): The official Expand Python SDK is coming soon.
- [Quickstart](https://review.expand.ai/docs/quickstart): Run your first Fetch from the CLI or a coding agent in one step, then pick the surface you will build on.
- [Concurrency tiers](https://review.expand.ai/docs/tiers): How tiers raise the browser concurrency included with your account, how they are reached, and what they do not change.
- [TypeScript SDK](https://review.expand.ai/docs/typescript-sdk): Call Fetch, Highlights, Search, Batched Fetch, Crawl, and WebSync from TypeScript with @expandai/sdk, and turn the results into citation links.
- [Why Expand](https://review.expand.ai/docs/why-expand): Your agent reads the HTML. It should see the page. What ordinary Markdown APIs drop, and how Expand keeps it.
- [Crawl](https://review.expand.ai/docs/crawl): Give Crawl a URL and get the pages it finds within your limits, each one a full Fetch, as a stream you can resume.
- [Batched Fetch](https://review.expand.ai/docs/fetch/batched-fetch): Send a list of URLs in one request, then poll one run ID for the results as they finish, without holding a request open per page.
- [Browser-rendered pages](https://review.expand.ai/docs/fetch/browser-rendered-pages): Fetch opens each page in a real browser and runs its JavaScript before writing the Markdown, State JSON, and a Snapshot you can replay.
- [PDFs and other files](https://review.expand.ai/docs/fetch/documents): Fetch a PDF, image, office file, ebook, data file, or audio file, and get the same agent-ready Markdown back.
- [Fetching a URL](https://review.expand.ai/docs/fetch/fetching-a-url): The two modes, what to include in a Fetch, and the pointers to everything held back.
- [Overview](https://review.expand.ai/docs/fetch): Fetch renders live pages and returns agent-ready Markdown, State JSON, and replayable Snapshots with evidence.
- [Iris](https://review.expand.ai/docs/fetch/iris): The vision model for browser page Fetches. Iris looks at the rendered page and decides what goes in the Main Markdown, what moves to the Appendix, and what is dropped.
- [X-Ray](https://review.expand.ai/docs/fetch/x-ray): The model for browser page Fetches that finds the data behind the page and returns what is useful as State JSON, next to the Main Markdown.
- [YouTube videos](https://review.expand.ai/docs/fetch/youtube): Fetch a YouTube video and get its transcript back as Markdown, with title, description, chapters, and timestamps.
- [Highlights](https://review.expand.ai/docs/highlights): Narrow a Fetch to what matches your query and get ranked, cited snippets instead of the whole document.
- [Working with snippets](https://review.expand.ai/docs/highlights/snippets): A snippet is one passage of the page that matches your query. Highlights returns a ranked list of snippets, under highlights.snippets, instead of the whole document. A snippet can come from the Main Markdown, State JSON, or Appendix.
- [Two ways to highlight](https://review.expand.ai/docs/highlights/two-ways-to-highlight): Highlights can be used on new Fetch requests, as well as on existing Snapshots. We call them Fetch Highlights and Snapshot Highlights, respectively.
- [Search](https://review.expand.ai/docs/search): Send a question and get back the pages on the web most relevant to it, ranked, each with its title and an excerpt, for 1.5 credits.
- [Search, then fetch](https://review.expand.ai/docs/search/search-then-fetch): Search finds the pages that answer a question. Fetch reads them, and Highlights pulls out the passages that answer it.
- [Wayback Machine](https://review.expand.ai/docs/wayback-machine): Browser page Fetches save a Snapshot you can replay, cite, and read again without fetching twice.
- [Playground & replay](https://review.expand.ai/docs/wayback-machine/playground-and-replay): Replay the page Fetch captured, see where each line of Markdown came from, and give your users a link to the exact evidence behind an answer.
- [Progressive disclosure](https://review.expand.ai/docs/wayback-machine/progressive-disclosure): Fetch once, then go back to the Snapshot for more. Read the original HTML, the network requests, or the whole archive without fetching the page again.
- [WebSync](https://review.expand.ai/docs/websync): A crawl that keeps going. Expand rechecks every page on the schedule you set and streams each change as an event.