AP3 Playground
A guided, glass-box demo of AP3: discovery → compatibility → protocol run → inspection.
What you’ll do here
This playground spins up two local AP3 agents, lets you configure their advertised capabilities, checks compatibility, then runs PSI and shows everything “under the hood” (HTTP, envelopes, directives, and receiver-side checks).
Playground servers
Initiator agent
A2A URL
http://127.0.0.1:18082
AgentCard endpoint
/.well-known/agent-card.json
Acts as the AP3 initiator and sends the first protocol envelope (msg1).
Receiver agent
A2A URL
http://127.0.0.1:18083
AgentCard endpoint
/.well-known/agent-card.json
Validates the intent + envelope (session binding, signature, participants, msg1 hash, replay) and responds.
The playground UI talks to these agents and captures A2A HTTP to populate the Inspector.
Flow
  1. Discovery: read AgentCards + AP3 extension (roles, ops, commitments, public key)
  2. Compatibility: score + explanation (why compatible / incompatible)
  3. Protocol run: execute PSI over A2A JSON-RPC
  4. Inspector: view request, HTTP trace, envelopes, directives, audit checks, logs
AP3 Playground
Start with Compatibility Lab, then inspect protocol runs.
Compatibility Lab
Initiator
Receiver
Computing compatibility…
AgentCards (preview)
Initiator AgentCard JSON

                
Receiver AgentCard JSON

                
AP3 Playground
Inspector + Playground
Walkthrough
PSI outcome
Attacks
Not started.