contextsmith

contextsmith is a CLI that builds the context bundle you give to a language model. It works like grep, but its question is “which code should I paste into Claude?”

The problem

When you use an LLM on a real codebase, you must decide how much context to give it.

Too little context	Too much context
The model invents APIs	You go over the context window
It hallucinates function names	You pay for tokens you did not need
It misses the answer	Round-trips are slow

You can copy files, trim them, and count tokens by hand. I find that the worst part of the workflow.

What it does

You run contextsmith on a repo with a query or a path glob. It selects files and trims them deterministically. It counts tokens for the model you target. Then it writes a clean bundle that you can paste or pipe. The same input always gives the same output. It makes no network calls and uses no model, so you do not wait on anything.

I wrote it in Rust because a context tool must be fast. It handles large repos with many files in less than a second.