v3.0.0

Breaking release: the discovery documents now follow the current specifications.

Breaking changes

A2A agent card (A2A 1.0). buildA2AAgentCard emits the 1.0 card shape:

• url, preferredTransport, protocolVersion and additionalInterfaces move into the required supportedInterfaces[] (url, protocolBinding, protocolVersion). The builder's inputs are unchanged.
• The extended-card flag moves to capabilities.extendedAgentCard: the supportsAuthenticatedExtendedCard option is removed, use extendedAgentCard.
• stateTransitionHistory is removed.
• security becomes securityRequirements, on the card and on each skill.
• Code that reads the card JSON for url reads supportedInterfaces[0].url.

UCP profile (UCP 2026-08-25). The profile publishes keys (a JWK Set) at version 2026-08-25 in place of signing_keys. buildUCPProfile takes keys; signing_keys is still accepted as an input alias. supported_versions is no longer published. wellKnownUcpUrl on buildSignedUcpResponse and mountUcpRoutes* is optional and ignored.

Added

• x-payment-info carries MPP payment-discovery offers[] (integer amount in the rail's smallest unit, null for a dynamic price) beside the existing price and protocols. New offersFrom in @agent-score/commerce/discovery.
• New exports: toSecurityRequirements, A2ASupportedInterface, A2ASecurityRequirement, A2AAgentCardSkill.

What's Changed

• Release 3.0.0: A2A 1.0 agent cards, UCP 2026-08-25 profiles, MPP payment offers by @vvillait88 in #141

Full Changelog: v2.15.0...v3.0.0