Registries

PEAC Protocol maintains registries for extension keys, attestation types, and advisory classifications. These registries define the standard vocabularies that all implementations use to describe interactions, payments, and other protocol events.

Extension keys

Extensions use reverse-DNS namespaced keys under peac.extensions. This namespacing prevents collisions between first-party and third-party extensions.

Extension Example

{
  "peac": {
    "extensions": {
      "org.peacprotocol/interaction@0.1": {
        "tool_name": "search",
        "tool_server": "https://tools.example.com"
      },
      "com.example/custom@0.1": {
        "custom_field": "value"
      }
    }
  }
}

Registered extension keys

Key	Version	Description	Status
org.peacprotocol/interaction	@0.1	Tool call and interaction metadata	Stable
org.peacprotocol/attribution	@0.1	Attribution requirements and commitments	Stable
org.peacprotocol/dispute	@0.1	Dispute evidence and resolution	Stable
org.peacprotocol/workflow	@0.1	Workflow correlation identifiers	Stable

Third-party extensions

Third-party extensions use reverse-DNS keys under their own domain (e.g., com.example/my-extension@0.1). No registration is required for third-party keys -- the namespace itself prevents collisions.

Attestation types

Attestation types categorize the kind of evidence a receipt carries. Each receipt has exactly one attestation_type.

Type	Description	Use case
interaction	General interaction evidence	API calls, tool use, agent conversations
payment	Payment and commerce evidence	x402, Stripe, Razorpay, card transactions
consent	Consent and terms acceptance	User agreements, data processing consent
identity	Agent identity attestation	Agent authentication, key binding

Advisory registries

Advisory registries define informational vocabularies. Unlike extension keys, advisory registry values are not enforced at the schema level -- they provide standard terminology that implementations should use for interoperability.

toolcall_op_types

Types of tool call operations. Used in the org.peacprotocol/interaction@0.1 extension to classify what kind of operation a tool call represents.

Type	Description
read	Read-only data access
write	Data modification
execute	Command execution
query	Search or query operation
subscribe	Event subscription

toolcall_resource_types

Types of resources accessed by tool calls. Used alongside toolcall_op_types to describe what resource a tool call targeted.

Type	Description
api	REST or GraphQL API endpoint
database	Database query or mutation
file	File system access
network	Network resource
compute	Compute resource

Protocol registries

The specs/kernel/registries.json file also defines registries for payment rails, control engines, transport methods, and agent protocols:

Registry	Contents
payment_rails	x402, L402, card-network, UPI, Razorpay
control_engines	Spend control, risk engine, mandate service, TAP, RSL
transport_methods	DPoP, HTTP message signatures, none
agent_protocols	MCP, ACP, AP2 (Google), TAP (Visa)

Normative specification

The normative registry definitions are maintained in:

Registry Spec Location

specs/kernel/registries.json

Adding to registries

First-party extension keys and attestation types are registered by submitting a pull request to the PEAC Protocol repository. Advisory registries are informational and can be extended without breaking changes. Third-party extension keys do not require registration.