Error Codes

ARC Protocol error codes and handling.

Standard RPC Errors

Borrowed from JSON-RPC convention:

Code	Message	Description
-32600	Invalid Request	Malformed request
-32601	Method not found	Unknown method
-32602	Invalid params	Invalid parameters
-32603	Internal error	Server error

ARC-Specific Errors

Code	Message	Description
-42001	Agent not found	Target agent unavailable
-42002	Authentication failed	Invalid credentials
-42003	Task not found	Task ID not found
-42004	Task processing error	Task execution failed
-42005	Chat not found	Chat ID not found
-42006	Invalid agent state	Agent in invalid state
-42007	Rate limit exceeded	Too many requests
-42008	Insufficient scope	Missing required OAuth scope

Error Response

{
  "error": {
    "code": -42001,
    "message": "Agent not found",
    "data": {
      "targetAgent": "nonexistent-agent",
      "availableAgents": ["agent-1", "agent-2"]
    }
  }
}

Error Handling

Client-Side

from arc import Client
from arc.exceptions import ARCException

client = Client("https://api.example.com/arc")

try:
    response = await client.chat.start(...)
except ARCException as e:
    if e.code == -42001:
        print("Agent not found")
    elif e.code == -42002:
        print("Authentication failed")
    else:
        print(f"Error: {e.message}")

Server-Side

from arc import Server
from arc.exceptions import ARCException

server = Server(server_id="my-server")

@server.agent_handler("my-agent", "chat.start")
async def handle_start(params, context):
    if not is_valid_request(params):
        raise ARCException(code=-32602, message="Invalid params")
    
    # Process request
    return {...}

Full Specification

See complete error handling: ARC Specification Document