Herdr Plugin Setup

Herdr is a terminal workspace manager for coding agents. The Upstash Box plugin runs your agent inside a box instead of on your machine: focus a pane in a Git worktree, start an agent, and the plugin uploads that worktree to a new box and opens the agent in a new pane.

Your local files are never edited directly. Changes come back when you run Apply changes and approve the patch.

1. Requirements#

• Herdr 0.8.0 or newer
• Node.js 22 or newer
• Git and tar
• An Upstash Box API key
• A provider credential for the default TUI mode: a Claude subscription token or an API key

2. Install the plugin#

herdr plugin install upstash/herdr-upstash-box

3. Set up#

herdr plugin action invoke setup --plugin upstash.box

A popup asks for your Upstash Box API key and checks it before going on, then asks which agent to run, which mode, and which provider credential, and saves the answers for you. Keys are typed without echo.

Keys#

Keys are read from the environment first, so if you start Herdr from a terminal, exporting them is enough:

export UPSTASH_BOX_API_KEY=...export CLAUDE_CODE_OAUTH_TOKEN=...

Herdr started from the Dock or Spotlight does not see your shell exports, which is why setup writes a secrets.json instead, in the directory printed by herdr plugin config-dir upstash.box:

{  "UPSTASH_BOX_API_KEY": "...",  "CLAUDE_CODE_OAUTH_TOKEN": "..."}

The provider credential follows your model's prefix. For anthropic/ models Claude Code takes CLAUDE_CODE_OAUTH_TOKEN (a subscription token from claude setup-token) or ANTHROPIC_API_KEY; openrouter/ reads OPENROUTER_API_KEY, openai/ reads OPENAI_API_KEY, and opencode/ reads OPENCODE_API_KEY.

4. Configure#

config.json, next to secrets.json, is optional. Every key has a default, and setup writes the ones it asked about:

{  "mode": "tui",  "harness": "claude-code",  "model": "anthropic/claude-sonnet-5",  "providerApiKeyEnv": "CLAUDE_CODE_OAUTH_TOKEN"}

harness is claude-code, codex, or opencode. model is a Box model id with its provider prefix. Claude Code takes anthropic/ and openrouter/ models, Codex needs an openai/ model, and OpenCode takes any. providerApiKeyEnv names the one variable that carries the credential; leave it out and the plugin picks the variable that fits the model.

mode decides what runs in your pane:

• tui runs the real agent terminal UI inside the box, using your provider credential.
• native runs the Upstash Box CLI, using the Box managed key. Required for the scheduled and typed runs in step 8.

Every setting is listed in the plugin README.

5. Start an agent#

Focus a Herdr pane inside a Git worktree, then run:

herdr plugin action invoke start-agent --plugin upstash.box

The command only confirms in your terminal. The new pane opens in Herdr.

The plugin lists the files it will upload, creates the box, unpacks the worktree, and opens the agent. Credentials and .env files are left out of the upload, and every excluded file is shown with its reason first. Use excludedPaths to leave more out and allowSensitivePaths to keep something the filter would drop.

Bind it to a key so this is one keystroke:

[[keys.command]]key = "prefix+shift+u"command = "herdr plugin action invoke start-agent --plugin upstash.box"

To start on a different agent for one launch without editing config.json, use start-claude, start-codex, or start-opencode in place of start-agent.

6. Use the agent#

herdr plugin action invoke reconnect --plugin upstash.boxherdr plugin action invoke apply-changes --plugin upstash.boxherdr plugin action invoke info --plugin upstash.boxherdr plugin action invoke stop --plugin upstash.box

You can close the agent pane at any time and the agent keeps working. Reconnect brings it back, resuming the box first if it paused while you were away.

Apply changes exports what the agent changed as a Git patch, checks it against your worktree, and applies it after you approve.

Info shows the box status and paths. Stop ends the session and keeps the box.

7. Manage boxes#

herdr plugin action invoke pause --plugin upstash.boxherdr plugin action invoke resume --plugin upstash.boxherdr plugin action invoke snapshot --plugin upstash.boxherdr plugin action invoke previews --plugin upstash.boxherdr plugin action invoke delete-box --plugin upstash.boxherdr plugin action invoke dashboard --plugin upstash.box

Boxes pause on their own when idle. Snapshot saves the box state, and Previews exposes a configured port with a public URL.

The dashboard lists every box with its worktree, agent, and live status, and runs any action on the selected row:

[j/k] Select  [enter/r] Reconnect  [a] Apply  [i] Info  [s] Stop  [p] Pause  [u] Resume[n] Snapshot  [f] Fork  [v] Previews  [t] Run task  [h] Results  [c] Schedules[d] Delete  [R] Refresh  [q] Close

Delete boxes from here rather than from the Upstash console, so the plugin forgets them too.

8. Scheduled and typed runs#

In native mode, a box can run the agent server-side with nothing attached:

herdr plugin action invoke run-task --plugin upstash.boxherdr plugin action invoke schedules --plugin upstash.boxherdr plugin action invoke run-results --plugin upstash.box

Run task takes a prompt and a JSON Schema and stores the typed result. Schedules manages cron schedules with c <cron> | <prompt> to create, and p, r, d with a schedule id to pause, resume, and delete. Run results shows recent runs.

A schedule wakes a paused box when it fires, so it can run up model and compute costs while Herdr is closed.

Troubleshooting#

The upload is too large. Uploads are capped at 100 MiB in total and 10 MiB per file, and Box rejects anything over 100 MB, so raising maxUploadBytes will not get you past it. The error names the heaviest directories. Exclude them:

{ "excludedPaths": ["img", "public/video"] }

Claude Code answers 401 OAuth access token is invalid. The subscription token in secrets.json is wrong, usually a paste that lost part of it or a token from an earlier claude setup-token run. Run claude setup-token again, run setup, press r at the credential prompt to replace the token, then run stop and reconnect so the agent restarts with the new one.

A second Start is refused. One box per worktree is the default. Reconnect to the existing box, or delete it from the dashboard, then start again.

An action says another popup is already open. Herdr shows one popup at a time. Close it and try again.

Native mode connects to the wrong API. The box CLI reads a .env from your worktree. If it sets UPSTASH_BOX_BASE_URL, unset it or set the same value where Herdr runs.

Next steps#