Web - Aster

Aster ships a built-in web MCP server. Five operations, usable from the shell and callable by the agent during a turn:

aster web search "query" [--limit 5] [--region us-en] [--safesearch strict]
aster web extract https://…
aster web crawl https://… [--max-pages 100] [--max-depth N] [--url-regex R] [--main-content-only] [--follow-subdomains] [--no-pdfs] [--stop-after-ms 80000]
aster web sitemap docs.rs [--max-links 500] [--url-regex R]
aster web screenshot https://… [--full-page]

Search and extract return clean Markdown, made for reading by a model.

Keys

Operation	Needs
`search`, `extract`	Nothing
`crawl`	`FIRECRAWL_API_KEY`, or `CONTEXT_DEV_API_KEY`, or the Cloudflare pair
`sitemap`, `screenshot`	`CONTEXT_DEV_API_KEY`

aster key list --all shows every web key you have set and what each one buys. Keys live in .env files like every other key; aster key set CONTEXT_DEV_API_KEY writes one.

In chat

The same five are the agent’s web/search, web/extract, web/crawl, web/sitemap, and web/screenshot tools. Ask it to look something up and it picks one; results arrive as Markdown in the turn. mcp.tools.deny can filter them like any other MCP tool.