ai-core/debug-logging

Debug Logging

Dependency note: This skill builds on ai-core. Read it first for critical rules.

Use this skill when you need to turn debug logging on or off, narrow what's printed, or pipe logs into a custom logger (pino, winston, etc.). The same debug option works on every activity — chat(), summarize(), generateImage(), generateSpeech(), generateTranscription(), generateVideo().

Turn it on

import { chat } from '@tanstack/ai'
import { openaiText } from '@tanstack/ai-openai'

const stream = chat({
  adapter: openaiText('gpt-5.2'),
  messages,
  debug: true, // all categories on, prints to console
})

Each log line is prefixed with an emoji and [tanstack-ai:<category>]:

📤 [tanstack-ai:request] 📤 activity=chat provider=openai model=gpt-5.2 messages=1 tools=0 stream=true
🔁 [tanstack-ai:agentLoop] 🔁 run started
📥 [tanstack-ai:provider] 📥 provider=openai type=response.output_text.delta
📨 [tanstack-ai:output] 📨 type=TEXT_MESSAGE_CONTENT

Turn it off

chat({
  adapter: openaiText('gpt-5.2'),
  messages,
  debug: false, // silence everything, including errors
})

Omitting debug is not the same as debug: false. When omitted, the errors category is still on (errors are cheap and important). Use debug: false or debug: { errors: false } for true silence.

DebugOption — the accepted shapes

type DebugOption = boolean | DebugConfig

interface DebugConfig {
  // Per-category flags. Any flag omitted from a DebugConfig defaults to true.
  request?: boolean
  provider?: boolean
  output?: boolean
  middleware?: boolean
  tools?: boolean
  agentLoop?: boolean
  config?: boolean
  errors?: boolean
  // Optional custom logger. Defaults to ConsoleLogger.
  logger?: Logger
}

Resolution rules for the debug?: DebugOption field on every activity:

debug value	Effect
omitted (undefined)	Only errors is active; default ConsoleLogger.
true	All categories on; default ConsoleLogger.
false	All categories off (including errors); default ConsoleLogger.
DebugConfig object	Each unspecified flag defaults to true; logger replaces ConsoleLogger.