Fitter Playground

declarative web-data extraction, running as WebAssembly in your browser loading engine… GitHub ↗

Source

parse as

start end step

name

Model

path syntax follows “parse as”: gjson for json/pdf, CSS selectors for HTML, XPath for xpath/XML

References

named cached sub-configs — use one as the Source (“Reference”) or inline via {{{RefName=name path}}} / {{{RefName=name}}}

Limits

max parallel requests per host (host_request_limiter)

Result

Engine loading — the fitter Go binary is compiled to WebAssembly (~7 MB gzipped), first load takes a moment…

Every run executes the real fitter engine — the same code as the CLI and MCP server — entirely client-side. Live HTTP examples use CORS-friendly public APIs (GitHub, OpenLibrary, CoinGecko); arbitrary page scraping and the browser/docker connectors need the native binary. Get it via go install github.com/PxyUp/fitter/cmd/fitter_cli@latest or the MCP server from the README.