Auto Agent Protocol 3.1

One open automotive contract for MCP, A2A and Personal Agent Protocol. Discover dealerships, search real inventory, verify vehicle facts and send customer-approved inquiries.

Website · Specification · FAQ · Migration · Full spec for agents

Native in all three interfaces

A full AAP 3.1 dealer deployment serves its implemented skill subset through all three. A buyer client needs only its chosen binding. AAP does not require a dealer-side language model or a new CRM.

A working MCP endpoint is required. The generated mcp.json catalog describes tools; it is not a server. See conformance and runtime acceptance.

Discovery starts at the dealership

The service may run on a provider’s infrastructure. Every entry point identifies the same dealership and actual capabilities. Discovery helps compatible agents find a service; it does not guarantee that every assistant will choose it.

Start from the Agent Card, Poppy document and dealer llms.txt. These release-pinned templates use fictional dealers: replace their identity, URLs and capabilities before deployment. Discovery requirements →

Five skills, one automotive journey

Dealer information · Facets · Search · Vehicle detail · Lead submission

Browse without shopper contact details. Submit a lead only with explicit consent, permitted channels and an idempotency key. A received inquiry and a confirmed appointment are separate outcomes.

What is new in 3.1

• Native Canadian values: explicit currency: "CAD" and mileage_unit: "km" preserve listing and trade-in numbers. Omitted labels retain USD/miles.
• Comparable inventory: search and facets select one currency and an odometer comparison unit. Prices never mix CAD and USD; mileage comparisons use exact conversion. Geographic and electric-range _mi fields remain miles.
• Consistent discovery: supported currencies and query defaults agree across MCP and A2A metadata. Nondefault result contexts are explicit, including empty results.
• Preserved contracts: the published 3.0 contract and existing connector endpoints retain their meanings. Native MCP, A2A 1.0 and PAP draft 0.3 continue unchanged.

This is an additive minor release. AAP 2.x implementations must also complete the earlier 3.0 major migration. Published contracts remain immutable. Migration guide →

Automotive detail, shared across vehicle types

Known prices include mandatory dealer charges; only government-required consumer charges are excluded. Optional fee itemization explains the existing total. Unknown equipment and prices stay unknown.

Vehicle shape · Pricing · Consent and behavior · CRM / ADF mapping

Payments, financing approval, reservations and trade-in valuations are outside AAP’s scope.

Use the packages

npm install @autoagentprotocol/[email protected] @autoagentprotocol/[email protected] @autoagentprotocol/[email protected]

Build and verify

Use Node.js 22+ and the pnpm 10 version pinned in package.json. Corepack and recent pnpm launchers select that version automatically; both CI workflows use the same pin. Run heavy checks one at a time.

pnpm install --frozen-lockfile
pnpm validate
pnpm test:contract
pnpm typecheck
pnpm build

Official MCP and A2A clients exercise real HTTP contract fixtures. PAP checks cover discovery, identity, session schemas and generated OpenAPI. These validate the specification; each production deployment must also verify live authentication, inventory, consent and CRM behavior.

See all verification commands, release preparation and visual generation.

Contribute

Contribution guide · Security reports · Code of conduct · Brand assets

Specification, schemas and code: Apache-2.0. Documentation prose: CC BY 4.0.