Tracing

rspc-tracing wraps a procedure with a tracing span and logs its elapsed time, input, and result. It uses Rust's tracing ecosystem.

Attach the middlewareCopy Anchor Link

Add rspc-tracing from the same Git revision as the core crate, then attach it to a procedure builder:

let procedure = rspc::Procedure::builder::<ApiError>()
    .with(rspc_tracing::tracing())
    .query(|_: (), _: ()| async { Ok("hello") });

ApiError is the error type from the procedure guide. Initialize a tracing subscriber in your application to display or collect the events. The middleware does not install one.

The input and error types must implement Debug. Outputs must implement the crate's Traceable trait; ordinary debug values and supported streams have implementations.

Data and implementation limitsCopy Anchor Link

Inputs and results are logged with debug formatting. Do not attach this middleware to procedures that contain passwords, access tokens, or private data unless you have reviewed the resulting logs. A custom middleware can log only safe fields.

The prototype reads procedure names from metadata, but the core rewrite still supplies a placeholder name. Do not rely on it for accurate per-procedure metrics. It does not capture transport serialization failures or provide Prometheus metrics.