Capabilities, precisely.
Protocol names describe direction. Implementation status describes what you can use.
| Protocol | Aisle status | Available today |
|---|---|---|
| MCP | Implemented · sandbox | Streamable HTTP, version 2025-06-18. Eight tools; scoped bearer access. All commerce is mock. |
| ACP | Limited preview | Single-item, ACP-shaped checkout endpoints with mock payment only. Full conformance is not validated. |
| UCP | Planned | No implementation or discovery manifest. Scope and interoperability testing remain future work. |
| PAP / Poppy | Guest preview | Draft 0.2 signed-out, read-only MCP subset for preregistered agents. Sign-in, DPoP and full conformance are not implemented. |
| AP2 | Planned | No payment mandates, delegated payment execution or AP2 implementation. |
| A2A | Planned | No A2A tasks, messages or Agent Card. No interoperability claim. |
Implemented MCP sandbox
MCP Streamable HTTP specification, 2025-06-18. JSON-RPC POST supports initialize, ping, notifications, tools/list and tools/call. JSON responses; no GET event stream. Scoped bearer authentication and Origin validation apply. See the connect guide.
ACP-shaped preview
/checkout_sessions supports a single-item mock create, retrieve, update, complete and cancel flow. Completion requires a separate approval and fixed mock payment data. This is not a validated ACP implementation. No Shared Payment Token, live checkout, platform approval or merchant activation is claimed. Full schema/capability validation, buyer/address handling, payment integration, webhooks and interoperability testing remain incomplete. ACP checkout reference.
PAP / Poppy guest preview
This means Personal Agent Protocol draft 0.2, not AP2. The actual sandbox Poppy manifest advertises a guest MCP subset. Only preregistered clients with pinned HTTPS metadata and JWKS URLs can request signed-out sessions using ES256 client/session assertions. Registration is operator-managed; there is no public registration endpoint.
Use the existing sandbox hostname for issuer, audience and MCP resource binding. Do not substitute aisle.market or the direct Supabase URL in signed assertions. Read the authorization-server metadata and MCP protected-resource metadata. Sessions are read-only, use resource-bound bearer tokens, and do not enable account sign-in or purchasing.
Account Tokens, signed-in flows, DPoP, conversations and full PAP conformance are not implemented. An API preview is not evidence of Meta integration or Poppy certification. PAP draft reference.
Planned: UCP, AP2 and A2A
No handlers, validated discovery manifests, payment mandates or Agent Card are published for these protocols. They are roadmap directions with no availability date or conformance claim. Aisle does not advertise protocol discovery on this landing-page domain; supported discovery remains at the existing sandbox issuer.
Machine-readable status
capabilities.json is an informational status document, not a standards-compliant discovery manifest. llms.txt provides an agent-readable overview. Always verify current API health and response schemas before using a sandbox endpoint.