One workspace for you and your coding agents.

Ostia is a terminal for macOS and Linux where you run coding agents beside your shell, then watch, guide and approve their work. It brings no agent of its own: use Claude Code, Codex or any CLI.

Download Source

The Ostia window. The sidebar lists six projects in two groups with their agent states. In marlow-api an agent has made a change and asks whether to apply a migration, and the diff of its change is open beside it.

Run agents. Several agent sessions in one window. The sidebar shows which is working, which is waiting for you and which is done.

The agent sessions in these captures are scripted stand-ins running in the real app.

See which agents need you

Each agent reports whether it is working, waiting for you or done. The sidebar and the notifications show that for every project at once.

Ostia's sidebar: marlow-api waiting with a question, marlow-web needing approval, marlow-sdk done, harbor-infra working, tidepool with a failed command, handbook idle.

The notification list: a permission request from marlow-web with Deny and Allow once, an agent in marlow-api that needs input, and an agent in marlow-sdk that finished.

Agents use the same app you do

Every terminal in Ostia has a pine command. An agent uses it to open tabs, a browser and diffs, and you watch each one appear.

pine process run "node server.js" --name web
Runs the server in a new tab that you can watch or stop.
pine browse open http://127.0.0.1:4173/invoices
Opens the page in Ostia's browser, where the agent can read and click it.
pine git open src/routes/invoices.ts
Opens the file's changes as a diff beside the shell.
pine state waiting "Apply migration 0014?"
Marks the project as waiting, shows the question in the sidebar and rings the terminal.

Show an agent exactly what you mean

Select code, terminal output or an element on a page and add a note. The agent gets the exact location, a screenshot and, from a page, its console errors.

From a file
Sends the file path, the selected lines and your note.

Lines selected in idempotency.ts and a Send to agent card over them: the file and line range, a note asking whether a replay should check that the key has not expired, and Claude Code chosen as the agent. — From a file
Sends the file path, the selected lines and your note.

From a page
Sends the element you clicked, its styles, a screenshot and any console errors.

A browser pane on the invoices page with a table cell picked. The Send to agent card says what is wrong, long customer names are cut off, and sends it to Codex. — From a page
Sends the element you clicked, its styles, a screenshot and any console errors.

You decide what an agent may do

Approve agent requests
Ostia pauses a request that needs a new permission. Allow it once, allow it for that terminal, or deny it.

An agent paused at pine browse open. The card reads: wants to drive the in-app browser, with Deny, Allow for this pane and Allow once. — Approve agent requests
Ostia pauses a request that needs a new permission. Allow it once, allow it for that terminal, or deny it.

Limit an agent's access
In a sandboxed project, shells reach only its folder and the network hosts you allow. Anything else asks you first.

A sandboxed shell. Reading an SSH key fails, and a request to api.stripe.com waits on a card with Deny, Allow until restart and Allow for this workspace. — Limit an agent's access
In a sandboxed project, shells reach only its folder and the network hosts you allow. Anything else asks you first.

Customise the workspace

Your own sidebar sections

Describe a sidebar section in one JSON file. An agent can write it for you, and Ostia shows it once you switch it on.

agents.json in the editor: a sidebar view that lists every workspace with its state.

The section that file produces in the sidebar: each workspace with waiting, done, working, error or idle beside it, and a button for a new scratch workspace.

Extensions from any git repository

Add a repository that lists extensions, install the ones you want, and approve each before it runs. Write your own in any language.

{
  "id": "weather",
  "name": "Weather",
  "api": "1.1",
  "capabilities": ["notify"],
  "contributes": { "paneChips": true }
}

Extension SDK

Themes, prompt and shortcuts

Pick a theme, then give the terminal or the editor its own colour scheme. Choose what your prompt shows and set your own keyboard shortcuts.

Appearance settings: the Oxocarbon theme, separate terminal and editor colour schemes with a live preview, and accent colour choices.

Also built in

Commands keep their output: Each command and its output are one unit. Select it to copy it, rerun it or send it to an agent.
Your layout comes back: After a restart Ostia restores your layout and terminal history. Running processes do not come back.
Separate windows: Move a project or a single terminal to another window. Its shells keep running through the move.
Quick code editing: Files open in a Monaco editor. Diagnostics and completion come per language, as extensions.
An optional assistant: Chat, command suggestions and completions on a local or hosted AI model. It stays off until you pick one.
Sync settings to your own folder: Copy settings to a folder you control. Secrets and agent permissions stay on this machine.

Download Ostia for macOS and Linux

Version 0.5.9, published October 7, 2026, for macOS 13 or later on Apple silicon and Linux on x64.

brew install --cask aurigax-ai/tap/ostia

On Linux, get the tarball or the .deb from the download page.

Download