Config

Configure BAML logging and environment settings via environment variables or programmatic API.

Environment Variables

Setting	Environment Variable	Description	Default
Logging Level	BAML_LOG	Log level: INFO, DEBUG, TRACE, WARN, ERROR, OFF	INFO
JSON Mode	BAML_LOG_JSON	Log in JSON format: 1 or 0	0
Max Message Length	BAML_LOG_MAX_MESSAGE_LENGTH	Max prompt/response log size (0 for no limit)	64000
Color Mode	BAML_LOG_COLOR_MODE	Color output: auto, always, never	auto

Programmatic API

Python

from baml_client.config import (
    set_log_level,
    set_log_json_mode,
    set_log_max_message_length,
    get_log_level,
    reset_baml_env_vars
)

set_log_level

def set_log_level(level: "INFO" | "DEBUG" | "TRACE" | "WARN" | "ERROR" | "OFF"):
    ...

set_log_json_mode

Switches between JSON and human-readable format.

def set_log_json_mode(enable: bool):
    ...

set_log_max_message_length

Set 0 for unlimited.

def set_log_max_message_length(length: int):
    ...

get_log_level

def get_log_level() -> "INFO" | "DEBUG" | "TRACE" | "WARN" | "ERROR" | "OFF":
    ...

reset_baml_env_vars

Deprecated

reset_baml_env_vars is deprecated and safe to remove. Environment variables are now lazily loaded on each function call.

def reset_baml_env_vars(env: Dict[str, str]):
    ...

TypeScript

import {
    setLogLevel,
    setLogJsonMode,
    setLogMaxMessageLength,
    getLogLevel,
    resetBamlEnvVars
} from '@/baml_client/config'

setLogLevel

setLogLevel(level: "INFO" | "DEBUG" | "TRACE" | "WARN" | "ERROR" | "OFF"): void

setLogJsonMode

Switches between JSON and human-readable format.

setLogJsonMode(enable: boolean): void

setLogMaxMessageLength

Set 0 for unlimited.

setLogMaxMessageLength(length: number): void

getLogLevel

getLogLevel(): "INFO" | "DEBUG" | "TRACE" | "WARN" | "ERROR" | "OFF"

resetBamlEnvVars

Resets environment variables to provided values.

resetBamlEnvVars(env: Record<string, string | undefined>): void

Ruby

# Not implemented yet
# Please use environment variables instead

Setting Environment Variables

Environment variables can be set in your shell, .env file, or programmatically:

# Shell
export BAML_LOG=DEBUG
export BAML_LOG_JSON=1

# .env file
BAML_LOG=DEBUG
BAML_LOG_JSON=1

Or pass environment variables via with_options:

Python

from baml_client import b

my_b = b.with_options(env={"BAML_LOG": "DEBUG"})
result = my_b.MyFunction("input")

TypeScript

import { b } from "baml_client"

const myB = b.withOptions({ env: { BAML_LOG: "DEBUG" } })
const result = await myB.MyFunction("input")

See Also

• with_options - Configure client options