Shale

A language for agents, built by agents.

Shale is for the everyday work on a project's files: finding things, reading them, renaming across a tree, editing in place, and writing up what it found.

Common file work, built in. Walk a folder, grep it, rename a word across every file, edit with a diff printed for each change.
Every run has a budget. Steps, files read, bytes, changes. A loop that never ends is stopped, and the run says where.
Mistakes stop loudly. A missing file is an error, never an empty string, and every stop names its line.

Start the tutorial Fifteen short lessons. It runs in your browser; there is nothing to install.

A Shale script from the tutorial renames a tag across a blog's posts. Beside it, the lines it changed, its report, and the blog's files with the two changed ones marked. — Lesson 13 of the tutorial, as it really runs: a tag renamed across a blog.