x0-registry

Program ID: Bebty49EPhFoANKDw7TqLQ2bX61ackNav5iNkj36eVJo x0-registry is the protocol’s agent discovery layer. Agents register with an endpoint URL and a set of capabilities, making themselves discoverable to other agents and services.

Instructions

`register_agent`

Registers a new agent in the discovery registry. Requires a listing fee of REGISTRY_LISTING_FEE_LAMPORTS = 100,000,000 (0.1 SOL).

register_agent(endpoint: String, capabilities: Vec<Capability>)

Parameter	Type	Constraints
`endpoint`	`String`	Max 256 bytes, must be a valid URL
`capabilities`	`Vec<Capability>`	Max 10 capabilities per agent

`update_registry`

Updates the agent’s endpoint and/or capabilities.

update_registry(
    new_endpoint: Option<String>,
    new_capabilities: Option<Vec<Capability>>
)

`deactivate_entry`

Marks the agent as inactive. The registry entry remains on-chain but is excluded from discovery queries.

`reactivate_entry`

Reactivates a previously deactivated entry.

`deregister_agent`

Permanently removes the agent from the registry and closes the account, reclaiming rent.

State Account

AgentRegistry

pub struct AgentRegistry {
    pub version: u8,
    pub agent_id: Pubkey,
    pub endpoint: String,                  // Service URL (max 256 bytes)
    pub capabilities: Vec<Capability>,     // Up to 10 capabilities
    pub price_oracle: Option<Pubkey>,      // Optional price feed
    pub reputation_pda: Pubkey,            // Link to reputation account
    pub last_updated: i64,
    pub is_active: bool,
    pub owner: Pubkey,
    pub bump: u8,
}

PDA Seeds: ["registry", agent_id]

Capability

Each capability describes a service the agent offers:

pub struct Capability {
    pub capability_type: String,    // e.g., "text-generation", "image-analysis"
    pub metadata: String,           // JSON metadata (max 256 bytes)
}

The metadata field is a JSON string stored on-chain. It typically contains:

{
  "model": "gpt-4",
  "price_per_request": 1000000,
  "max_tokens": 4096,
  "supported_formats": ["text", "json"]
}

Discovery

Agents can be discovered by:

Iterating registry PDAs — Use getProgramAccounts with filters on capability_type
SDK helper — X0Client.findAgents(capabilityType) fetches and filters matching agents
Reputation check — Each registry entry links to a reputation PDA for trust scoring

Registry Constants

Constant	Value	Purpose
`REGISTRY_LISTING_FEE_LAMPORTS`	100,000,000 (0.1 SOL)	Anti-spam listing fee
`MAX_ENDPOINT_LENGTH`	256 bytes	Maximum URL length
`MAX_CAPABILITIES_PER_AGENT`	10	Max capabilities per registration
`MAX_CAPABILITY_TYPE_LENGTH`	64 bytes	Max capability type string
`MAX_CAPABILITY_METADATA_LENGTH`	256 bytes	Max metadata JSON per capability
`REGISTRY_TTL_SECONDS`	300 (5 min)	Client-side cache TTL

Events Emitted

Event	When
`AgentRegistered`	New agent registered
`RegistryUpdated`	Endpoint or capabilities changed
`AgentDeregistered`	Agent removed from registry

Overview

Core Programs

Zero-Knowledge

Application Layer

Reference

Instructions

`register_agent`

`update_registry`

`deactivate_entry`

`reactivate_entry`

`deregister_agent`

State Account

AgentRegistry

Capability

Discovery

Registry Constants

Events Emitted

​Instructions

​register_agent

​update_registry

​deactivate_entry

​reactivate_entry

​deregister_agent

​State Account

​AgentRegistry

​Capability

​Discovery

​Registry Constants

​Events Emitted

Instructions

`register_agent`

`update_registry`

`deactivate_entry`

`reactivate_entry`

`deregister_agent`

State Account

AgentRegistry

Capability

Discovery

Registry Constants

Events Emitted