Infrastructure · Data Structures
Card
Structured capability advertisement: agent_id, endpoint, protocols, capabilities, metadata
Definition
Mechanism
Structured capability advertisement enabling agent discovery before contact. Agent creates CARD: {agent_id (unique), endpoint (how to reach), protocols[] (compatibility), capabilities[] (what agent claims to do), constraints (availability, rate limits, requirements), metadata (version, ttl, published timestamp)}. Agent PUBLISHES card via registry, broadcast, DHT, or well-known endpoint (mechanism-agnostic). Discovering agents QUERY using LatentAttachment for semantic capability matching alongside exact protocol_match. Query returns ranked CARD list. Discoverer selects promising CARDs, then Greets at card.endpoint to establish channel. CARDs have TTL — agents maintain visibility by PUBLISHING a replacement card before the previous one expires, never by editing the one already issued. CARD capabilities are CLAIMS not proofs: verification happens via Probe after GREET establishes channel. It enables discovery via Select queries against the registry, filtering candidates by capability and protocol compatibility.
Invariants
- Immutable after issue: a Card is never edited. A change of endpoint, protocol or capability is published as a new Card superseding the old, which is what lets a discoverer tell a current claim from a stale one rather than trusting a mutable record.
- Claims, not proofs: the capabilities a Card advertises are assertions the issuer has not demonstrated. Verification is the discoverer's, via Probe after Greet opens a channel.
Risks
Failure modes
Stale CARDs (agent changed capabilities, CARD not updated—TTL mitigates).
False claims (CARD says X, agent cannot X—PROBE mitigates).
Registry unavailable (discovery fails—use multiple publication methods).
CARD spam (fake CARDs pollute discovery—use reputation/filtering).
Privacy leak (CARD reveals too much about agent—include only necessary info).
Version skew (CARD protocol version differs from actual—GREET catches this).
Relationships
Builds on
Composes with
Generic selection of items from a set based on criteria
References
Mind
Autonomous Goal-Directed Entity
Agent connection initiation
Mind
Vector embedding bound to a card without entering its hash
Active verification query
Used by
References
Society
Advertise capabilities and discover collaborating agents
Mind
Breaking local optima
Mind
Solver implementing the five-surface contract (polymorphic across substrates)
Society
Discover and invoke external tools via structured capability manifests
Reference
Parameters
verification_tierEnum, {SelfReported, Verified, Bonded}- Default: SelfReported
Data schema
{
"type": "object",
"required": [
"public_key",
"claims"
],
"properties": {
"public_key": {
"type": "string",
"description": "Cryptographic identifier of the Agent"
},
"claims": {
"type": "object",
"description": "Map of protocols and capabilities supported"
},
"reputation_score": {
"type": "number",
"description": "Aggregate trust metric (optional)"
},
"endpoints": {
"type": "array",
"description": "Reachability addresses"
}
}
}