src/middleware/redaction.rs

This file scrubs secrets from tool output before anything else sees them, under the redaction feature. Put it in your chain when your tools read files you do not control.

Key items

You build the layer with RedactingMiddleware::new(SecretPatternSet).

Your SecretPatternSet::default_common() ships named regex patterns: bearer, api_key_kv, aws_access_key, pem_private_key, github_pat, and gitlab_pat.

Append your own patterns with with_pattern(SecretPattern), and turn the heuristic off with with_entropy_heuristic(false).

The entropy heuristic flags tokens of at least 32 chars carrying at least 4.5 bits/byte randomness as [REDACTED:high_entropy]. Hex hashes top out at 4.0 and stay visible to you.

Behavior notes

Replacement shape is [REDACTED:<kind>] per match, and scrub returns the count for observability.

This layer works post-execution only. It rewrites text parts, multipart included, never touches images, never sets is_error, and preserves display hints, so it has zero effect on loop semantics.

Register it outer, before verifiers, so it also scrubs what your inner layers append.

Deep dive: Middleware.