Logging from a TypeScript Agent

TypeScript agents log using the standard console API. Golem captures stdout and stderr and streams them to golem agent stream and golem agent invoke output.

Quick Start

Use the built-in console methods — no imports or setup needed:


console.log("order created:", orderId);
console.info("processing item", itemId);
console.warn("retry attempt", attempt, "for request", reqId);
console.error("failed to connect to database:", err);
console.debug("detailed flow: entered processItem");

Log Levels

Method	Behavior	Use for
`console.trace(...)`	Prints with stack trace to stderr	Fine-grained debugging with call stack
`console.debug(...)`	Writes to stdout	Debugging information
`console.log(...)`	Writes to stdout	General output
`console.info(...)`	Writes to stdout	Monitoring, normal operations
`console.warn(...)`	Writes to stderr	Hazardous situations, degraded behavior
`console.error(...)`	Writes to stderr	Serious errors

Structured Logging

For structured output, log JSON objects:


console.log(JSON.stringify({
  level: "info",
  event: "order_created",
  orderId,
  timestamp: new Date().toISOString(),
}));

Or use template literals for readable messages with context:


console.info(`[${agentName}] counter incremented to ${this.count}`);

Viewing Logs

Stream live agent output (stdout and stderr):


golem agent stream '<agent-id>'

Or during an invocation:


golem agent invoke '<agent-id>' '<method>' [args]
# Logs stream automatically; use --no-stream to suppress

Key Points

No setup needed — console is available globally in the QuickJS runtime
Golem captures both stdout (console.log, console.info, console.debug) and stderr (console.warn, console.error) streams
Logs are recorded in the oplog and visible via golem agent stream and golem agent invoke
Logging is a side effect — during replay (crash recovery), log output from replayed operations is skipped; only new invocations produce log output
The TypeScript SDK does not currently expose a direct wasi:logging/logging binding — use console methods for all logging needs