#Output, Errors, and Color

Nodeup supports human output for operators and JSON output for automation.

#Human Output

Human output is the default:

nodeup show active-runtime

Management commands write a concise human result to stdout. Human errors are written to stderr with this shape:

nodeup error: <cause>. Hint: <next action>.

#JSON Output

Use JSON mode for scripts:

nodeup --output json show home
nodeup --output json toolchain list

Successful command payloads are pretty-printed JSON on stdout. Handled failures are JSON envelopes on stderr:

{
  "kind": "invalid-input",
  "message": "<cause>. Hint: <next action>.",
  "exit_code": 2
}

Stable envelope fields:

• kind
• message
• exit_code

kind values include internal, invalid-input, unsupported-platform, network, not-found, conflict, and not-implemented.

ANSI styling is never injected into JSON stdout or stderr payloads.

#Delegated Commands in JSON Mode

nodeup run --output json ... keeps stdout reserved for the final Nodeup response. Delegated command stdout is routed to stderr in JSON mode.

The final payload is:

{
  "runtime": "v22.1.0",
  "command": "node",
  "exit_code": 0
}

The Nodeup process exits with the delegated command's exit code.

#Completion Output

nodeup completions always writes raw shell script text to stdout. It does not wrap output in JSON, even when --output json is supplied.

#Human Color Precedence

Human stdout and stderr color controls use this precedence:

1. --color auto|always|never
2. NODEUP_COLOR=auto|always|never
3. NO_COLOR
4. stream-aware auto

auto enables ANSI styles only when the relevant stream is a terminal. Invalid NODEUP_COLOR values are ignored.

Examples:

nodeup --color never show active-runtime
NODEUP_COLOR=always nodeup show home
NO_COLOR=1 nodeup show home

#Log Color

Logs use NODEUP_LOG_COLOR=always|auto|never. The default is colored logs unless NO_COLOR disables color. NODEUP_LOG_COLOR=always overrides NO_COLOR.

#Logging Defaults

Default filters depend on context:

• Managed alias dispatch: nodeup=warn
• Human management commands: nodeup=info
• JSON management commands: nodeup=off

Set RUST_LOG to override logging:

RUST_LOG=nodeup=debug nodeup show active-runtime

Keep RUST_LOG unset or off when a script needs clean JSON output.