Request Invoke a function that has been registered with the framework.
Response The framework responds with an InvocationResult message.
Message type. Will be "invocationresult".
UUID that identifies this invocation. Matches the request’s invocation_id if provided.
The ID of the function that was invoked.
The successful result from the function. Omitted if the invocation failed.
Error details if the invocation failed. Omitted if successful. Machine-readable error code (e.g., "function_not_found", "timeout", "execution_error").
Human-readable error message describing what went wrong.
W3C trace-context traceparent header, propagated from the request or generated.
W3C baggage header, propagated from the request.
Examples Basic Function Invocation Request: { "type" : "invokefunction" , "function_id" : "process_payment" , "data" : { "amount" : 99.99 , "currency" : "USD" } }
Success Response: { "type" : "invocationresult" , "invocation_id" : "550e8400-e29b-41d4-a716-446655440000" , "function_id" : "process_payment" , "result" : { "transaction_id" : "txn_abc123" , "status" : "completed" } }
Invocation with Custom ID Request: { "type" : "invokefunction" , "invocation_id" : "550e8400-e29b-41d4-a716-446655440000" , "function_id" : "send_email" , "data" : { "to" : "user@example.com" , "subject" : "Welcome!" , "body" : "Thanks for signing up." } }
Success Response: { "type" : "invocationresult" , "invocation_id" : "550e8400-e29b-41d4-a716-446655440000" , "function_id" : "send_email" , "result" : { "message_id" : "msg_xyz789" , "status" : "sent" } }
Invocation with Distributed Tracing Request: { "type" : "invokefunction" , "function_id" : "process_order" , "data" : { "order_id" : "ord_123" , "items" : [{ "sku" : "ITEM-001" , "quantity" : 2 }] }, "traceparent" : "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01" , "baggage" : "user_id=12345,session_id=abc" }
Success Response: { "type" : "invocationresult" , "invocation_id" : "7c9e6679-7425-40de-944b-e07fc1f90ae7" , "function_id" : "process_order" , "result" : { "order_status" : "confirmed" , "estimated_delivery" : "2026-03-05" }, "traceparent" : "00-4bf92f3577b34da6a3ce929d0e0e4736-b7ad6b7169203331-01" , "baggage" : "user_id=12345,session_id=abc" }
Error Cases Function Not Found Request: { "type" : "invokefunction" , "function_id" : "nonexistent_function" , "data" : {} }
Error Response: { "type" : "invocationresult" , "invocation_id" : "550e8400-e29b-41d4-a716-446655440000" , "function_id" : "nonexistent_function" , "error" : { "code" : "function_not_found" , "message" : "No function registered with ID 'nonexistent_function'" } }
Execution Error Request: { "type" : "invokefunction" , "function_id" : "divide_numbers" , "data" : { "numerator" : 10 , "denominator" : 0 } }
Error Response: { "type" : "invocationresult" , "invocation_id" : "550e8400-e29b-41d4-a716-446655440000" , "function_id" : "divide_numbers" , "error" : { "code" : "execution_error" , "message" : "Division by zero" } }
Timeout Error Error Response: { "type" : "invocationresult" , "invocation_id" : "550e8400-e29b-41d4-a716-446655440000" , "function_id" : "slow_operation" , "error" : { "code" : "timeout" , "message" : "Function execution exceeded timeout of 30000ms" } }
Notes
The invocation_id is used to correlate requests with responses
If no invocation_id is provided, one will be generated automatically
The result and error fields are mutually exclusive - only one will be present
For HTTP-based functions, the HTTP response body is returned as the result
For WebSocket-based functions, the worker must send an InvocationResult message
Distributed tracing headers follow the W3C Trace Context specification