Drinky

A dependency-free terminal coding agent you can read end to end.

Give Drinky a prompt in the terminal. The model can read, search, and change files or run commands in the working directory. Drinky talks to:

• Anthropic
• OpenAI
• xAI
• OpenRouter
• DeepSeek
• Gemini Enterprise Agent Platform (Vertex AI)

Drinky is a single Zig program. It needs no Node.js runtime or third-party package tree, so a complete review covers Drinky and the Zig standard library. Use Drinky as it is, or fork it and add the features your workflow needs.

Highlights

1. Terminal-native: The conversation stays in the normal scrollback. A session is the process, and Drinky saves no conversation to resume.
2. One job: An agent loop and a small set of tools, with no workflow mode. A skill or an instruction file can tell an agent to start another agent with drinky run.
3. Small system prompt: The compiled prompt states the mechanics. Your instruction files and skills carry every rule about how to work.
4. Self-describing: The model can read every slash command, config key, and key binding of Drinky, so it can maintain your config file for you.
5. No compiled-in models: Every model comes from the provider at runtime, and every limit and price from the provider or the public metadata.

Build and run

Drinky requires Zig 0.17.0, a POSIX system, and the HOME variable. A terminal with the Kitty keyboard protocol and grapheme cluster processing gives the best experience. The project uses Ghostty for development and testing.

Build and run the executable in the safe optimization mode:

zig build -Doptimize=safe
./zig-out/bin/drinky

Sign in

An account reads vendor-product, and a model under it reads account/model, as in anthropic-plan/claude-opus-4-8. A -key suffix marks a credential that an environment variable holds or names.

Account	Credential
anthropic-plan	Claude Pro or Max login
anthropic-api	Anthropic Console login, which mints and stores an API key
anthropic-api-key	ANTHROPIC_API_KEY
openai-plan	ChatGPT login
openai-api-key	OPENAI_API_KEY
xai-plan	SuperGrok or X Premium login with a device code
xai-api-key	XAI_API_KEY
openrouter-api	OpenRouter login, which mints and stores an API key
openrouter-api-key	OPENROUTER_API_KEY
deepseek-api-key	DEEPSEEK_API_KEY
google-cloud-key	GOOGLE_APPLICATION_CREDENTIALS and GOOGLE_CLOUD_LOCATION

Run /login to sign in with an account that has no -key suffix. A successful sign-in opens its model or author list. The first row fetches or refreshes that list. Drinky puts the cursor on the remembered model or OpenRouter author when that row is available. Only an active model appears as current. Set the variable of a -key account by hand. For google-cloud-key, set the Agent Platform service account key file in GOOGLE_APPLICATION_CREDENTIALS. Set GOOGLE_CLOUD_LOCATION to eu, us, or global.

Drinky is not affiliated with Anthropic, OpenAI, xAI, OpenRouter, DeepSeek, or Google.

Cost display

The status line shows the session cost as an estimate, as in ~$0.42, and the tilde marks it. Drinky prices the tokens of the session at the public rates of the model. When a reply states its charge, as an OpenRouter reply does, Drinky takes that charge. The figure is informational, and it is not a bill. A subscription account pays no per-token price at all, and Drinky still prints the figure as an orientation about the weight of a session. Drinky never sees the bill.

The context gauge, the quota window, and the credit pool are different. Each one reports what the provider states.

Slash commands

A line that starts with a slash runs in Drinky and reaches no model. Type / or /help to open the complete command list. Drinky refuses an unknown command, an unknown skill, and a command with an argument. A second Enter then sends the refused line to the model as a message.

Use /compact to toggle Full and Compact transcript modes, even during a turn. Compact mode hides thinking text behind a summary with received bytes, elapsed time, and status. It removes the padding inside boxes. The gaps between transcript blocks stay. Each toggle clears terminal scrollback and repaints the complete transcript without a warning. Full mode restores the thinking text and the box padding. The transcript keeps thinking after a cancellation or failure, without changing the model conversation. Compact mode also preserves the complete transcript when an update requires a terminal reset.

Set interface.transcript_mode to "compact" or "full" in the config file to select the startup mode. The default is "full". The command changes only the current session and never writes the config file.

Headless mode

drinky run answers one prompt without a terminal. It reads the prompt from stdin and writes the text of the final reply to stdout. The --model flag takes an account/model value. The --effort flag takes low, medium, high, xhigh, or max, and Drinky uses the nearest level that the model takes.

drinky run --model openai-plan/gpt-5.5 --effort high <<'EOF'
Review the uncommitted changes.
EOF

drinky models lists the account/model values of each signed-in account with a saved model list. Fetch a list with /model first. A run uses the config file, the instruction files, the skills, and the tools of a session. Its skill list leaves out each skill that sets drinky-run: hidden in the block map of its metadata. It saves no choice and signs in to no account. A failure of the run goes to stderr, and the exit code is then 1. A run that stops at a limit also fails, but its last reply text still reaches stdout. A run drops the start reports of a session, such as an unknown config key or an instruction file that Drinky cannot read.

Each command of the bash tool gets DRINKY_MODEL with the account/model value of the session. It also gets DRINKY_EFFORT with the effort level that you chose. Both follow /model and /effort, so an agent can start a run with its own model and effort.

A run sets DRINKY_RUN for its commands, and Drinky refuses to start a run where that variable is set. An agent can start a reviewer, but the reviewer cannot start another agent.

Herdr

Inside a Herdr pane, Drinky reports its state over the Herdr socket, so Herdr can notify you when a turn ends. The status line leaves the directory and the branch to the Herdr pane label. This needs no setup.

Config file

The ~/.drinky/config.json file is optional. It controls instruction files, request and bash limits, required skills, a default effort level, and the interface. Drinky reads the file only at startup and never writes it. You can keep it in version control.

The config file holds no secrets. Credentials, project state, and cached model information live in separate files under ~/.drinky/.

Security

The AGENTS.md files and the skills in a repository are model instructions. Drinky has no permission gate or sandbox. Open an untrusted repository in a container.

Name and inspiration

Drinky takes its name from Homer Simpson's drinking bird, which repeatedly presses Y on his remote nuclear plant workstation.

Drinky takes inspiration for its terminal rendering model from pi.

License

Drinky is available under the MIT License.