Coming at this from having just shipped the same shape of interface. ERC-8354 (Confidential Agent Policy Verdicts) defines a prover-agnostic verifier boundary, verifyProof(programKey, publicInputs, proof), with a Noir circuit compiled to an UltraHonk verifier that runs on-chain behind it. So the abstraction here holds up in practice, not just on paper.
The IProofVerifier / IAgentVerifier split is the right cut, and it rhymes with something we just landed in the 8354 thread, separating the action-level property (what the proof establishes about a specific claim) from the layer above it (application authorization, and further up, whether the verifier itself is trustworthy). babyblue is in both threads, so the resonance is not an accident.
One framing that might help the OCP discussion. Recompute-and-compare and proof-based verification are orthogonal, not competing. Some backends are publicly recomputable, some are zk proofs, and some are confidential and cannot be recomputed at all. 8354 lives in that last corner, the policy is never revealed, so there is nothing to recompute. A unified verifier interface is stronger if it does not assume recomputability, which makes OCP one profile among several rather than the base layer everything reduces to. IProofVerifier already reads that way to me, which is good.
I left three concrete notes on the PR rather than clutter here.
And a composition note, since it is close to home. A CAPV verdict is itself a verified agent action, so 8354 could sit on top of this, using an 8274 verifier as its backend. Happy to be a test integrator if that is useful.