Documentation Index Fetch the complete documentation index at: https://mintlify.com/iii-hq/sdk/llms.txt
Use this file to discover all available pages before exploring further.
init() Initialize a new III SDK instance and connect to the engine.
import { init } from 'iii-sdk' const iii = init ( address , options ? )
WebSocket URL of the III Engine (e.g., ws://localhost:49199)
Optional configuration for the SDK instance Show InitOptions properties
Custom worker name for identification. Defaults to hostname:pid
Enable automatic worker metrics reporting via OpenTelemetry
Default timeout for function invocations in milliseconds (2 minutes)
reconnectionConfig
Partial<IIIReconnectionConfig>
WebSocket reconnection behavior configuration Show Reconnection config properties
Initial delay before first reconnection attempt
Maximum delay between reconnection attempts
Exponential backoff multiplier for reconnection delays
Random jitter factor (0-1) to prevent thundering herd
Maximum retry attempts (-1 for infinite)
OpenTelemetry configuration. OTel is enabled by default. Show OpenTelemetry config properties
Enable OpenTelemetry. Set to false or env OTEL_ENABLED=false to disable
Service name for telemetry (also reads OTEL_SERVICE_NAME env var)
Service version (also reads SERVICE_VERSION env var)
Enable metrics export (also reads OTEL_METRICS_ENABLED env var)
Metrics export interval in milliseconds
fetchInstrumentationEnabled
Auto-instrument fetch() calls for HTTP client tracing
Custom OpenTelemetry instrumentations (e.g., PrismaInstrumentation)
Additional telemetry metadata Language/locale for telemetry
Project name for telemetry grouping
Framework name (e.g., “express”, “fastify”)
An initialized III SDK instance
Example import { init } from 'iii-sdk' const iii = init ( 'ws://localhost:49199' , { workerName: 'api-worker-1' , invocationTimeoutMs: 30000 , // 30 seconds reconnectionConfig: { maxRetries: 10 , initialDelayMs: 500 }, otel: { serviceName: 'my-api-service' , serviceVersion: '1.0.0' , metricsEnabled: true } })
Connection Management getConnectionState() Get the current connection state.
const state = iii . getConnectionState ()
Current connection state: 'disconnected' | 'connecting' | 'connected' | 'reconnecting' | 'failed'
onConnectionStateChange() Register a callback to be notified of connection state changes.
const unsubscribe = iii . onConnectionStateChange (( state ) => { console . log ( 'Connection state:' , state ) }) // Later: unsubscribe unsubscribe ()
callback
(state: IIIConnectionState) => void
required
Function called when connection state changes
Function to unregister the callback
Example: Connection State Handling import { init } from 'iii-sdk' const iii = init ( 'ws://localhost:49199' ) iii . onConnectionStateChange (( state ) => { switch ( state ) { case 'connected' : console . log ( '✓ Connected to III Engine' ) break case 'reconnecting' : console . warn ( '⟳ Reconnecting...' ) break case 'failed' : console . error ( '✗ Connection failed' ) break } })
Lifecycle Management shutdown() Gracefully shutdown the SDK, cleaning up all resources.
This method:
Stops all metrics reporting
Flushes and shuts down OpenTelemetry
Rejects all pending invocations
Closes the WebSocket connection
Clears all callbacks
Example: Graceful Shutdown import { init } from 'iii-sdk' const iii = init ( 'ws://localhost:49199' ) // Handle shutdown signals process . on ( 'SIGINT' , async () => { console . log ( 'Shutting down...' ) await iii . shutdown () process . exit ( 0 ) }) process . on ( 'SIGTERM' , async () => { console . log ( 'Shutting down...' ) await iii . shutdown () process . exit ( 0 ) })
Engine Queries listFunctions() List all functions registered across the III network.
const functions = await iii . listFunctions ()
Array of registered function information Show FunctionInfo properties
listWorkers() List all workers connected to the engine.
const workers = await iii . listWorkers ()
Array of connected worker information Show WorkerInfo properties
Runtime identifier (e.g., “node”)
Worker status: 'connected' | 'available' | 'busy' | 'disconnected'
Number of functions registered by this worker
Number of currently executing invocations
Example: Service Discovery // Discover available functions const functions = await iii . listFunctions () console . log ( 'Available functions:' ) for ( const fn of functions ) { console . log ( `- ${ fn . function_id } : ${ fn . description || 'No description' } ` ) } // Monitor worker health const workers = await iii . listWorkers () console . log ( ` \n ${ workers . length } workers online` ) for ( const worker of workers ) { console . log ( `- ${ worker . name } : ${ worker . function_count } functions, ${ worker . active_invocations } active` ) }