Rust Error Handling

Skill Resources

Activation and cross-agent notes: references/activation.md

Rust's error handling requires deliberate design decisions that compound across a codebase. The wrong choice at a module boundary forces changes across every caller. This skill covers the architecture decisions, not just the syntax.

The Core Boundary: `thiserror` vs `anyhow`

The single most important decision: are you writing library code or application code?

Concern	Library (`thiserror`)	Application (`anyhow`)
Callers programmatically match errors	Yes	No
Error types are part of the public API	Yes	No
Ergonomics of error propagation	Verbose	Ergonomic (`?` just works)
Error context chain	Manual	`context()` / `with_context()`
When to use	`src/services/*`, any reusable module	`src/handlers/*`, `main.rs`, scripts

rust-error-handling

Rust Error Handling

Skill Resources

The Core Boundary: thiserror vs anyhow

The Core Boundary: `thiserror` vs `anyhow`