Trustfall

Trustfall is a query engine for querying any kind of data source, from APIs and databases to any kind of files on disk — and even AI models.

Try Trustfall in your browser

The Trustfall Playground supports running queries against public data sources such as:

• the HackerNews REST APIs: https://play.predr.ag/hackernews
• the rustdoc JSON of top Rust crates: https://play.predr.ag/rustdoc

For example, this link shows the results of the HackerNews query: "Which GitHub or Twitter users are commenting on stories about OpenAI?"

In the Playground, Trustfall is configured to run client-side as WASM, performing all aspects of query processing (parsing, compilation, and execution) within the browser. While this demo highlights Trustfall's ability to be embedded within a target application, it is of course able to be used in a more traditional client-server context as well.

Examples of querying real-world data with Trustfall

• HackerNews APIs, including an overview of the query language and an example of querying REST APIs.
• RSS/Atom feeds, showing how to query structured data like RSS/Atom feeds.
• airport weather data (METAR), showing how to query CSV data from aviation weather reports.

Trustfall also powers the cargo-semver-checks semantic versioning linter. More details on the role Trustfall plays in that use case are available in this blog post.