Optionalsupported_Release-precision versions the seller does support (e.g. ['3.0', '3.1']).
Buyers can negotiate down to a member of this set.
Optionalrequested_The specific adcp_version value the buyer asked for, echoed back.
Optionalbuild_Seller's full semver build, advisory.
Structured details accompanying a
VERSION_UNSUPPORTEDAdCP error per specerror-details/version-unsupported.json(AdCP 3.1, spec PRadcontextprotocol/adcp#3493). Buyers read these from the error envelope to decide whether to downgrade their pin and retry rather than failing outright.