Environment variables (reference)

The environment variables murk reads, and the CLI flags they mirror where one exists. This is the terse reference. The narrative version with resolution order and interactions lives in the Environment variables concept page.

Identity and vault selection

Variable	Description
`MURK_KEY`	Your raw age private key (`AGE-SECRET-KEY-1…`), inline. Rejected for hardware-plugin identity strings (`AGE-PLUGIN-…`) — use `MURK_KEY_FILE` for those.
`MURK_KEY_FILE`	Path to a private-key file: a raw age key, an SSH PEM key, or an age plugin identity file. `murk init` writes this reference into `.env`.
`MURK_VAULT`	Vault filename, defaulting to `.murk`. Equivalent to passing `--vault` on every command (the one variable in the clap model).

Safety and agent context

Variable	Description
`MURK_STRICT`	Truthy fails closed rather than let a secret touch disk, and disables the automatic key lookup under `~/.config/murk/keys`.
`MURK_AGENT`	Marks the process as running for an AI agent. Forces strict mode unconditionally. `murk agent exec` sets it on its child.
`MURK_SELF_SCOPE`	Truthy holds your own key to the vault’s agent allow-tag policy, as if you were an agent. Implied inside an agent context.
`MURK_NO_SIGNER_PIN`	Opts out of signer-registry pinning (TOFU) on load — an escape hatch for a deliberate signer-key change, not for everyday use.

Also honored

Variable	Description
`CI`	Truthy prints a nudge toward the scoped-agent path when a pipeline decrypts with a personal key. Advisory only.
`EDITOR, VISUAL`	Editor launched by `murk edit`, checking `EDITOR` then `VISUAL`, falling back to `vi`.
`XDG_RUNTIME_DIR`	Preferred (typically tmpfs) scratch location for `murk edit`’s temporary file, over `/tmp`.
`HOME (USERPROFILE on Windows)`	Base directory for murk state: `~/.config/murk/keys`, `agent-keys`, and `signer-pins`.