Reputation & Passports

Scorecards From Signed Receipts

compute_local_scorecard (crate chio-reputation), which turns an agent's signed receipts, capability-lineage records, and budget-usage records into a LocalReputationScorecard across eight behavioral metrics. These include boundary pressure, resource stewardship, least-privilege adherence, delegation hygiene, and reliability.

When the inputs are signed receipts tied to the agent's workload identity, a counterparty can attribute the score to that identity and recompute the scorecard from the same signed inputs. Reproducibility depends on using the same scorecard implementation and input set.

{
  "note": "illustrative scorecard shape, not a fixed schema",
  "agentId": "did:chio:agent:9f2a...",
  "metrics": {
    "boundary_pressure": 0.94,
    "resource_stewardship": 0.88,
    "least_privilege_adherence": 0.91,
    "delegation_hygiene": 0.86,
    "reliability": 0.97
  },
  "tier": "tier_2"
}

Tiers and Sybil Resistance

A local scorecard feeds a separate composition layer: the ReputationFeed / ReputationTier system. It composes discrete signed deltas, not raw scorecards, into the marketplace-visibility tiers that counterparties actually see, tier_0 through tier_3.

Reaching tier_3 requires clearing a per-feed threshold of 0.80 AND-gated across independent feeds. A single feed cannot promote an agent to the top tier.

This AND gate limits promotion from a single controlled feed. Its Sybil resistance depends on the independence and integrity of the feeds used by the deployment.

The Agent Passport

The AgentPassport / ReputationCredential (crate chio-credentials) packages issuer-signed identity and reputation credentials for a relying party. The bundle itself may be unsigned. It supports:

• It projects into standard verifiable-credential formats, OID4VCI issuance, OID4VP presentation, and SD-JWT VC, so an external wallet can hold and present it without chio-specific tooling.
• Cross-issuer migration requires support from both issuers and the relying party.

An agent's principal can present an Agent Passport across operators. It does not transfer an operator's records or access policy.

Bound to Identity

Reputation can be attributed when receipts tie back to the same SPIFFE workload identity and DID. A scorecard recomputed later can identify the same actor a counterparty previously encountered. This identity binding lets an Agent Passport associate credentials with that actor across sessions and operators.

Using a Passport in a Market

A counterparty meeting an unfamiliar agent faces a pricing problem: extend it a wide capability and a large budget, or a narrow one? The An Agent Passport provides inputs for that decision. The counterparty can inspect it, recompute the scorecard from linked signed receipts, and set capabilities or budgets according to its own policy.

A future market could use such decisions in credit or underwriting. Chio does not currently provide that market service.

Summary

1. Scorecard inputs. compute_local_scorecard turns signed receipts, lineage, and budget-usage records into an eight-metric LocalReputationScorecard.
2. Tier requirements. Reaching tier_3 requires clearing a 0.80 threshold on independent feeds at once. The degree of Sybil resistance depends on those feeds.
3. Agent Passport presentation. AgentPassport supports OID4VCI issuance, OID4VP presentation, SD-JWT VC, and cross-issuer migration where issuers and relying parties support it.
4. Identity binding. Receipts tied to a SPIFFE identity and DID support attribution of a scorecard to that identity.
5. Current scope. The cross-market credit layer remains a roadmap direction.

Next Steps

• Workload Identity · the SPIFFE binding that associates a receipt with an actor
• Receipts · the signed receipts used to compute a scorecard
• Trust Model · the zero-ambient-authority stance reputation operates inside
• Reputation Scoring · the full ReputationFeed and tier composition mechanics
• Agent Passports · issuance, presentation, and cross-issuer migration in detail
• Credit Scorecards · how counterparties use an Agent Passport in a pricing decision