Environment Variables

Ambient mode reads its configuration from the environment at install time. Managed mode does not.

#Variables

Variable	Used for	Notes
`HTTP_PROXY`	proxy for `http:` and `ws:` URLs	upper case wins over lower
`HTTPS_PROXY`	proxy for `https:` and `wss:` URLs
`ALL_PROXY`	fallback when the protocol-specific variable is unset
`NO_PROXY`	comma- or whitespace-separated list of exemptions	matched against the destination URL
`http_proxy`	lowercase alias for `HTTP_PROXY`	upper case wins when both are set
`https_proxy`	lowercase alias
`all_proxy`	lowercase alias
`no_proxy`	lowercase alias

Empty or whitespace-only values are treated as unset.

#Activation

The ambient runtime is active when any of HTTP_PROXY, HTTPS_PROXY, or ALL_PROXY (or their lowercase forms) is set to a non-empty value.

NO_PROXY alone does not activate the runtime. With only NO_PROXY set, proxy.active is false and Proxyline installs no patches.

#Snapshot at install

The values are read once at installProxyline time. Changing process.env.HTTP_PROXY afterwards does not retroactively activate or reconfigure Proxyline. Call proxy.stop() and re-install if the environment changes.

#Proxy URL parsing

Bare endpoints (no scheme) default to http://. HTTPS_PROXY=proxy.corp:8080 becomes http://proxy.corp:8080.
http:// and https:// are the only accepted schemes. Anything else is ignored.
Userinfo (user:pass@) in the proxy URL becomes a Proxy-Authorization: Basic header.

#NO_PROXY matching

Entries are split on commas and whitespace. Matching rules, in order:

* alone matches everything. The URL goes direct.
Entries can include a port: internal.corp:8443. When present, the entry only matches the URL's port (defaulting to 80 for http/ws and 443 for https/wss).
Entries starting with . or * are suffix matches. .corp.example matches api.corp.example and corp.example. *.corp.example is equivalent.
Other entries are exact host matches.
IPv6 entries may be bracketed ([::1]:8443) or bare (::1). Bracketed forms are stripped before comparison.
Hostnames are lowercased and trailing dots are stripped before comparison.

When a URL matches NO_PROXY, explain() returns kind: "direct", reason: "no-proxy-match".

#Examples

# go through the proxy for everything except internal hosts
export HTTPS_PROXY="https://proxy.corp.example:8443"
export NO_PROXY=".corp.example,localhost,127.0.0.1,::1"

# only https traffic via proxy, http stays direct
export HTTPS_PROXY="https://proxy.corp.example:8443"

# fall through to ALL_PROXY for everything
export ALL_PROXY="socks-not-supported://example"   # ignored — only http/https proxies are honored
export ALL_PROXY="http://gateway.corp:3128"        # used for both http and https URLs

#Interaction with `fetch`

The undici global dispatcher is installed as EnvHttpProxyAgent in ambient mode and is configured with the exact same HTTP_PROXY / HTTPS_PROXY / NO_PROXY snapshot Proxyline read at install time. fetch and node:http therefore agree on the proxy decision for any URL.