Can we pass context.Context to custom Bloblang functions?

Hey team,

I’m writing some custom Bloblang functions for a Benthos pipeline, and I noticed I can’t get the tracing info (trace / span) that’s already on the message. The reason is the current function signature doesn’t give us a context.Context.

Right now it’s:

func myFunc(args ...any) (any, error) {
    // no ctx here
}

If we could write it like this instead:

func myFunc(ctx context.Context, args ...any) (any, error) {
    span := trace.SpanFromContext(ctx)
    // do stuff...
}

we could:

• keep end-to-end tracing intact (no more orphan spans)
• respect timeouts and cancellations coming from upstream

Locate the custom Bloblang function registration and the current func(args ...any) (any, error) entry point; read how the message context is available there. Done means custom functions can receive context.Context and use tracing information plus upstream timeout and cancellation behavior without breaking existing function behavior.