Reference · 3 min read

Environment variables

Environment variables Miton reads at startup — development overrides, provider keys, and paths. Most configuration belongs in Settings instead.

Product stage: Pre-release development
Last reviewed: 2026-07-23
Successful result: The change is visible in the active project.

Who this is for: developers and power users who configure Miton from a shell, CI job, or .env file rather than the Settings UI.

Prefer Settings for everyday options (model defaults, budgets, Studio port). Environment variables override file settings only where noted below.

Copy the repository’s .env.example to .env for local development.

Provider keys (BYOK)

Standard provider env vars are read for development convenience. In normal use, store keys in the app’s keychain via Settings → Models.

Variable	Purpose
`OPENAI_API_KEY`	OpenAI models
`ANTHROPIC_API_KEY`	Anthropic models
`GOOGLE_API_KEY`	Google Gemini models
`MISTRAL_API_KEY`	Mistral models
`OLLAMA_BASE_URL`	Local Ollama endpoint (default `http://localhost:11434`)
`CUSTOM_API_BASE_URL`	OpenAI-compatible base URL
`CUSTOM_API_KEY`	Key for the custom endpoint

Managed proxy (when enabled)

Variable	Purpose
`MITON_PROXY_URL`	Miton Cloud proxy endpoint
`MITON_PROXY_KEY`	Proxy authentication key

Development paths and logging

Variable	Default	Purpose
`MITON_LOG_LEVEL`	`info`	`debug`, `info`, `warn`, `error`, or `silent`
`MITON_CONFIG_DIR`	Platform app-data dir	Alternate config root

Documented in .env.example; use when running from source or automated tests.

Specialist overrides

Variable	Purpose
`MITON_AST_GREP_BIN`	Path to `ast-grep` binary for blueprint tooling
`MITON_PDF_FONTS_DIR`	Custom font directory for PDF export
`MITON_REFERRAL_<PLAN_ID>`	Override affiliate URL for a paid-plan id (upper snake case)
`MITON_BROWSER_CDP_ENDPOINT`	Loopback DevTools endpoint for the browser-automation CDP fallback

MITON_BROWSER_CDP_ENDPOINT deserves a note, because it is the one variable here that widens what the agent can reach. Browser automation drives the panel by injecting JavaScript; a page whose Content-Security-Policy refuses inline scripts drops that injection, and the fallback is to run the same script over Chrome DevTools Protocol instead. Miton never looks for a DevTools endpoint on its own — pointing it at one is the whole opt-in, because such an endpoint is total control over whatever is listening on it. Set it only to the debugging port of Miton’s own browser panel webview (http://127.0.0.1:9222, or the ws:// URL if you already have it). Non-loopback hosts are refused, and the fallback only ever evaluates against a page already showing the panel’s current URL — so aiming it at a browser of your own does not let the agent drive your tabs. Unset, the fallback is inert and a CSP-blocked action is simply reported as failed.

Override hierarchy

Where an env var is supported:

environment variable → .miton/settings.json → user settings.json → default

Not every Settings field has an env counterpart. If a variable is not listed here, configure it in the UI or project settings file.

Security notes