docs: add an environment-variable reference (#2365)

Every variable that changes runtime behavior now lives on one page,
docs/environment-variables.md: which client reads it, its default, and
its effect. It covers three variables that were undocumented
(MCP_LOG_FILE, MCP_INSPECTOR_LOG_DIR, LOG_LEVEL), the secret-store
variables previously only in the Docker guide, and the Node TLS
variables that answer #1936 (a self-signed https://localhost server).

The README docs table, the migration guide, docker.md and the four
client READMEs link to it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TRJ64MnDTg1TpzCTEV9Xva
Signed-off-by: cliffhall <cliff@futurescale.com>
This commit is contained in:
cliffhall 2026-09-13 23:35:30 -04:00
commit 2c1d3fdba8

View file

@ -84,7 +84,7 @@ When a server is loaded from a `--catalog`/`--config` file, its per-server setti
The file is the only durable way to give a run its roots: there is no roots flag, and `--method roots/set` applies only to that one short-lived connection. Roots configured for a server (the same field the web UI's Server Settings writes) are advertised at connect, so a server that asks for `roots/list` — `@modelcontextprotocol/server-filesystem` does, to learn its allowed directories — gets them.
**Environment-variable semantics.** `MCP_CATALOG_PATH` is honored only when no ad-hoc target is given (positional command, `--server-url`, or `--transport`) — so a shell that exports it can still run one-off ad-hoc invocations without hitting the catalog/ad-hoc conflict. `MCP_STORAGE_DIR` sets the storage directory used by the OAuth persist backend (`<MCP_STORAGE_DIR>/oauth.json`); the per-file `MCP_INSPECTOR_OAUTH_STATE_PATH` override still takes precedence over it.
**Environment-variable semantics.** `MCP_CATALOG_PATH` is honored only when no ad-hoc target is given (positional command, `--server-url`, or `--transport`) — so a shell that exports it can still run one-off ad-hoc invocations without hitting the catalog/ad-hoc conflict. `MCP_STORAGE_DIR` sets the storage directory used by the OAuth persist backend (`<MCP_STORAGE_DIR>/oauth.json`); the per-file `MCP_INSPECTOR_OAUTH_STATE_PATH` override still takes precedence over it. Every variable the CLI reads is listed in [Environment variables](../../docs/environment-variables.md).
### HTTP proxy support