Environment variable

In Node.js, everything is controlled by a single AGENTCRUMBS environment variable. In the browser, use configure() instead.

Shorthand values

Value	Effect
`1`	Enable all namespaces
`*`	Enable all namespaces
`true`	Enable all namespaces
(unset)	Disabled. All calls are noop.

AGENTCRUMBS=1 node your-app.js

Namespace filter

Non-JSON string values are treated as namespace filters:

AGENTCRUMBS=auth-*           # Wildcard match
AGENTCRUMBS=auth-service     # Exact match

JSON config

For full control, pass a JSON object:

# Enable specific namespaces
AGENTCRUMBS='{"ns":"auth-*,api-*"}'

# With exclusions
AGENTCRUMBS='{"ns":"* -internal-*"}'

# Custom port
AGENTCRUMBS='{"ns":"*","port":9999}'

# JSON output format (instead of pretty)
AGENTCRUMBS='{"ns":"*","format":"json"}'

# Explicit app name
AGENTCRUMBS='{"app":"my-project","ns":"*"}'

Config schema

Field	Type	Default	Description
`app`	`string`	(auto-detect)	App name. Defaults to nearest `package.json` name
`ns`	`string`	(required)	Namespace filter pattern
`port`	`number`	`8374`	Collector HTTP port
`format`	`"pretty"` \| `"json"`	`"pretty"`	Output format for stderr

App name

Every crumb is stamped with an app name. This keeps crumbs from different projects separate.

The app name is resolved in this order:

app field in the JSON config
AGENTCRUMBS_APP environment variable
Auto-detected from the nearest package.json name field (walking up from cwd)
Fallback: "unknown"

# Override via dedicated env var
AGENTCRUMBS_APP=my-project AGENTCRUMBS=1 node app.js

Namespace patterns

* matches everything
auth-* matches auth-service, auth-oauth, etc.
auth-*,api-* matches multiple patterns (comma or space separated)
* -internal-* matches everything except namespaces starting with internal-