The Settings screen writes one file, `.env`, in the desk folder. Nothing in it is required. This is every line by name, for a reader who would rather read the file than the screen, and for the agent that sets one on your behalf.
The desk
Line
What it does
DESK_PORT
The door number the desk answers on. 8765 unless you run two copies.
HOME_MARKET
Your country, as a two-letter code, when no broker sets it.
SCREENS
Screens you hid, as chain:off,short:off.
RISK_BENCHMARK, RISK_BENCHMARK_LABEL
The index Risk measures the home book against, and its name.
JOURNAL
Whether the desk writes its daily journal: ask, always or never.
EDGAR_CONTACT
The e-mail the SEC asks for with each request to EDGAR. Yours, set once.
Your broker
Each broker file names its own keys, listed in brokers/README.md; the ones that ship are ALPACA_KEY, ALPACA_SECRET, ALPACA_PAPER; BREEZE_API_KEY, BREEZE_API_SECRET (ICICI Direct); IBKR_FLEX_TOKEN, IBKR_FLEX_QUERY; TRADIER_TOKEN, TRADIER_ACCOUNT, TRADIER_SANDBOX; T212_KEY, T212_SECRET, T212_DEMO; KITE_API_KEY, KITE_API_SECRET (Zerodha). BROKER names the one on Desk · Home, BROKERS the list when more than one is connected. A broker with a daily session keeps the day's key in its own small file beside .env.
Your data provider
Line
What it does
FMP_API_KEY
The Financial Modeling Prep key, the provider that ships.
DATA_PROVIDER, DATA_API_KEY, DATA_BASE_URL
Another provider written to the contract: its name, its key, where it answers.
Your AI
Line
What it does
AI_PROVIDER, AI_MODEL, AI_API_KEY
The lab, the model and the key from Settings, Your AI.
AI_BASE_URL, AI_FORMAT
For Any other endpoint: where it answers and how it is spoken to.
AI_DOOR
The app on this computer that answers the Ask box (Claude Code, Codex and the rest) when you chose one instead of a key.
Updates and plugins
Line
What it does
DESK_AUTO_UPDATE
on applies a newer version without the click.
DESK_UPDATE_VERSION_URL, DESK_UPDATE_ZIP_URL
Point a fork or a private mirror at its own version file and zip.
PLUGIN_LIST_URL
Where the Plugins tab reads its list.
The file is never carried by an update or a backup, and the page your AI agent reads tells it not to read it. What it talks to.