Prompt injection is the number-one AI vulnerability on the OWASP Top 10 for 2025. For autonomous agents operating on-chain — executing transactions without human review — the attack surface is not an inconvenience; it is an existential risk to assets under management.
Software-layer guardrails cannot fully address this. An agent manipulated into generating a malformed intent can still produce a structurally valid-looking payload. Policy rules that evaluate well-formed payloads will process it. The manipulation happens before policy evaluation — which is exactly where Intent Sanitization operates.
Intent Sanitization is the ACP component designed to block prompt injection before signing. Other layers, such as Policy DSL and Intent-Evaluated MPC enforce authorization and signing controls, but Intent Sanitization is the semantic defense layer upstream.
The pipeline is pluggable: teams can extend stages with domain-specific detection logic without changing the core signing infrastructure.