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Policy Config YAML Reference

This page documents the complete YAML schema for CapiscIO policy configuration files.

Schema Version

Current schema version: 1

Top-Level Fields

Field Type Required Default Description
version string Yes — Must be "1"
min_trust_level string No "" Minimum trust level for all requests
allowed_dids string[] No [] Allowlist of agent DIDs
denied_dids string[] No [] Denylist of agent DIDs
rate_limits RateLimitRule[] No [] Per-DID rate limits
operations OperationRule[] No [] Operation-scoped rules
mcp_tools MCPToolRule[] No [] MCP tool-scoped rules

Trust Levels

Value Name Description
"" None No trust requirement
SS Self-Signed Agent has a self-signed key
REG Registered Agent is registered in the CapiscIO registry
DV Domain Validated Agent's domain ownership is verified
OV Organization Validated Agent's organization is verified
EV Extended Validation Agent has undergone extended validation

Trust levels are ordered: EV > OV > DV > REG > SS > "" (none).

DID Format

All DID values must conform to the DID syntax: they must start with did:.

Examples:

  • did:web:agent.example.com
  • did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK
  • did:web:registry.capisc.io:agents:my-agent

RateLimitRule

Field Type Required Description
did string Yes Agent DID to rate limit (must start with did:)
rpm integer Yes Requests per minute (must be > 0) 
rate_limits:
  - did: "did:web:caller.example.com"
    rpm: 100

Rate limits generate obligations in policy decisions. The PEP (Policy Enforcement Point) is responsible for tracking and enforcing rate limits.

OperationRule

Field Type Required Description
pattern string Yes Operation pattern to match (must not be empty)
min_trust_level string No Trust level override for this operation
allowed_dids string[] No Allowlist specific to this operation
denied_dids string[] No Denylist specific to this operation 
operations:
  - pattern: "payment.*"
    min_trust_level: "EV"
    allowed_dids:
      - "did:web:payment-processor.example.com"

The pattern field is matched against input.action.operation during policy evaluation.

MCPToolRule

Field Type Required Description
tool string Yes MCP tool name to match (must not be empty)
min_trust_level string No Trust level override for this tool
allowed_dids string[] No Allowlist specific to this tool
denied_dids string[] No Denylist specific to this tool 
mcp_tools:
  - tool: "database_query"
    min_trust_level: "OV"
  - tool: "send_email"
    min_trust_level: "EV"
    allowed_dids:
      - "did:web:notification-service.example.com"

The tool field is matched against input.action.mcp_tool during policy evaluation.

Validation Rules

The following rules are enforced during parsing and validation:

  1. version must be exactly "1"
  2. Trust levels must be one of: "", SS, REG, DV, OV, EV
  3. DID format: All DID strings must start with did:
  4. No duplicate DIDs within the same list
  5. No cross-listed DIDs: A DID cannot appear in both allowed_dids and denied_dids
  6. Rate limit RPM must be a positive integer
  7. Operation patterns must not be empty strings
  8. MCP tool names must not be empty strings

Minimal Valid Config

version: "1"
min_trust_level: ""

Full Example

version: "1"
min_trust_level: "DV"

allowed_dids:
  - "did:web:trusted-partner.example.com"

denied_dids:
  - "did:web:blocked-agent.example.com"

rate_limits:
  - did: "did:web:trusted-partner.example.com"
    rpm: 1000

operations:
  - pattern: "payment.*"
    min_trust_level: "EV"
    allowed_dids:
      - "did:web:payment-processor.example.com"
  - pattern: "admin.*"
    min_trust_level: "OV"

mcp_tools:
  - tool: "database_query"
    min_trust_level: "OV"
  - tool: "send_email"
    min_trust_level: "EV"