# Herdr

> Use this skill when running inside Herdr to coordinate workspaces, tabs, panes, sibling agents, server/test/log panes, agent-to-agent messages, or multi-agent delegation. Send a lightweight herdr-msg (reply-to + task). On delivered, stop. On unconfirmed, send Enter once then stop. Do not poll siblings and do not block-wait for replies; handle the peer message when it is injected into your pane.

- Skill: `yangyang0507/herdr` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add yangyang0507/herdr`
- Raw SKILL.md: https://api.skillmd.com/api/skills/yangyang0507/herdr/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: yangyang0507 (https://skillmd.com/u/yangyang0507)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/yangyang0507/herdr

---


# Herdr

Herdr is a terminal workspace manager for coding agents. Use it to inspect sibling panes, delegate to other agents, run servers or tests beside your current pane, and coordinate work without blocking.

For exact CLI syntax and less common workspace/tab/worktree operations, read [references/command-reference.md](references/command-reference.md).

## Preconditions

```bash
test "${HERDR_ENV:-}" = "1"
command -v herdr
```

If `HERDR_ENV` is not `1`, do not control live panes unless the user asked you to edit this skill or discuss Herdr. You may still read files and explain commands.

## Operating Rules

- Discover first: `herdr agent list`, `herdr pane list`.
- Treat IDs as live-session handles. Re-read them after layout changes.
- Prefer `HERDR_PANE_ID` as your pane handle when set; `HERDR_WORKSPACE_ID` / `HERDR_TAB_ID` name your workspace and tab.
- For async agent task handoff use `scripts/herdr-msg` or `herdr pane run` (the header carries **reply-to**). Use `herdr agent prompt <target> "<text>" --wait` only for one-shot prompts whose reply stays in your own pane — it submits with Enter and rejects blocked agents.
- Read a target **once** before sending, only to avoid interrupting a prompt/approval.
- **After send:** `herdr-msg` checks the target once. `state=delivered` → stop. `state=unconfirmed` → send Enter once to `target_pane`, then stop. Do not poll. Do not `herdr pane wait-output` / `--wait-reply` for normal chat. When a reply is injected into **your** pane, handle that inbound message.
- Do not use `herdr agent wait` / status waits for multi-agent coordination.
- Safety: do not close workspaces/tabs/panes you did not create unless the user asks; never run `herdr server stop` from an active session; prefer `--no-focus` for background work and `--current` / explicit IDs over relying on UI focus.

## Default Loop

1. Discover agents/panes.
2. Read the target **once** if needed.
3. Send a short request with `scripts/herdr-msg` (header carries **reply-to** + **task**).
4. On `state=delivered`: **end the turn**. On `state=unconfirmed`: send Enter once to `target_pane`, then end the turn.
5. When an inbound reply appears in your pane, integrate it.

## After `herdr-msg` (mandatory)

1. Non-zero exit → send/resolve failed; fix and resend. Do not poll.
2. `state=delivered` (exit 0) → obey `hint`: **stop**. Helper already checked once.
3. `state=unconfirmed` (exit 0) → check `enter_nudge` in the receipt:
   - `enter_nudge=0` → send Enter once (`herdr agent send-keys "$target_pane" Enter`), then **stop**.
   - `enter_nudge=1` → the helper already pressed Enter; do **not** press it again. **Stop.**
   Do not pane read. Do not wait. Do not resend. Do not loop.
4. The wake-up is the peer injecting a message into `reply-to` (your pane).
5. Polling the target after the one allowed Enter is a **protocol violation**.

## Lightweight agent messages

Keep it human and thin. One header line + body:

```text
[herdr-msg reply-to:<your-pane-id> task:<short-label>]
<short actionable message>
```

Optional fields the helper may add: `from:<name>`, `kind:reply` / `kind:update` (requests omit kind).

| Field | Role |
|-------|------|
| `reply-to` | **Required.** Where the peer should answer. |
| `task` | Human thread label (not a crypto id). |
| `from` | Optional sender label. |
| `kind` | Optional; default is request. |

**Not required for normal chat:** `msg_id`, sentinels, `ack-of`, status codes in the header, waiting recipes.

### Send (default)

```bash
scripts/herdr-msg codex --task auth-review <<'MSG'
Review src/auth.ts for auth bypasses and missing tests.
Reply to reply-to with DONE or BLOCKED findings.
MSG
# receipt: delivered → end turn; unconfirmed → Enter once, then end turn
```

### Reply

```bash
scripts/herdr-msg "$REPLY_TO" --task auth-review --kind reply <<'MSG'
DONE: Checked src/auth.ts. No bypass found. Missing refresh-token expiry test.
MSG
```

### Manual fallback

```bash
SELF=$HERDR_PANE_ID
TARGET=$(herdr agent get codex | sed -nE 's/.*"pane_id":"([^"]+)".*/\1/p')
herdr pane run "$TARGET" "[herdr-msg reply-to:$SELF task:auth-review]
Review src/auth.ts. Reply to reply-to with DONE or BLOCKED."
```

### Receipt

Tiny key=value lines: `ok`, `state`, `target`, `target_pane`, `reply_to`, `task`, `kind`, `enter_nudge`, `target_status`, `hint`.

`delivered` = helper saw `working`/`blocked` (or no agent). `unconfirmed` = still `idle`/`done` after the check — Enter once, then stop.

Agent states: `idle` = ready for input and its tab has been seen in the UI; `done` = the same idle state after unseen background work (the receipt treats it like `idle`); `blocked` = approval or question dialog; `unknown` = an agent is present but Herdr cannot classify it — `herdr-msg` treats it as started and does not nudge Enter. CLI reads never mark a tab seen; focusing the tab does.

## Waiting Policy

**Agent chat:** do not wait. Send, end turn, handle inbound reply later.

Use `herdr pane wait-output` only for **non-agent** processes (dev servers, tests) where you can name a concrete marker such as `ready` or `FAIL`:

```bash
herdr pane wait-output "$PANE" --match "ready" --timeout 30000
herdr pane read "$PANE" --source recent --lines 40
```

Use `--regex <pattern>` for Rust regex matching; `wait-output` also matches output that already exists before the wait starts.

Only use `herdr agent wait` / status waits when the user explicitly needs UI status or you are attaching/taking over an agent.

## Delegation Pattern

1. `herdr agent list`
2. Read target once.
3. `scripts/herdr-msg <target> --task <label> <<'MSG' ... MSG`
4. On delivered: **end turn**. On unconfirmed: Enter once, then end turn. No poll, no block-wait.
5. When replies arrive on your pane, integrate; follow up only for gaps.

## Starting Sibling Agents

`herdr agent start` launches a coding agent in an **existing available shell pane** (interactive prompt, no foreground command, shell in the foreground). It never splits or moves panes.

1. Split a sibling pane first. Geometry: a wide pane splits `right`, a narrow or tall one splits `down`; avoid repeated same-direction splits.
   ```bash
   PANE=$(herdr pane split "$HERDR_PANE_ID" --direction right --cwd "$PWD" --no-focus | sed -nE 's/.*"pane_id":"([^"]+)".*/\1/p')
   ```
2. Start the agent with a unique name and the kind the user asked for:
   ```bash
   herdr agent start reviewer --kind codex --pane "$PANE"
   ```
   Pass native agent arguments after `--` (`-- <agent-args...>`). Success means Herdr detected the agent in that pane and considers it ready for input. If it is blocked during startup you get `agent_not_ready`, but the name still works for `agent read` / `agent send-keys`; wait for `idle` before prompting.
3. Prompt it through the agent surface — `agent prompt` submits with Enter and `--wait` blocks until the first settled `idle`/`done`/`blocked` state:
   ```bash
   herdr agent prompt reviewer "Review the current diff. Reply with findings." --wait --timeout 120000
   ```
   Use `--until` only for state-specific waits, e.g. `herdr agent wait reviewer --until blocked --timeout 120000`.
4. Or hand off asynchronously with `scripts/herdr-msg reviewer --task <label>` and end your turn.

## Server And Test Panes

Split geometry: a wide pane splits `right`, a narrow or tall one splits `down`. For long-running panes, consider moving them to their own tab (`herdr pane move "$PANE" --new-tab --label logs`) and naming the outer terminal (`herdr terminal title set "dev server"`).

```bash
SELF=${HERDR_PANE_ID:-$(herdr pane list | sed -nE 's/.*\{[^{}]*"focused":true[^{}]*"pane_id":"([^"]+)".*/\1/p')}
PANE=$(herdr pane split "$SELF" --direction right --cwd "$PWD" --no-focus | sed -nE 's/.*"pane_id":"([^"]+)".*/\1/p')
herdr pane run "$PANE" "npm run dev"
herdr pane wait-output "$PANE" --match "ready" --timeout 30000 || true
herdr pane read "$PANE" --source recent --lines 50
```

For tests, wait for framework markers (`passed`, `failed`, `FAIL`, …) or run tests in your own session.

## Diagnostics

When state, detection, or layout looks wrong:

- `herdr status --json` — client/server protocol compatibility.
- `herdr agent explain <target>` — why an agent is or is not detected.
- `herdr server agent-manifests` — active agent detection manifests.
- `herdr api snapshot` — full live session snapshot (agents, panes, workspaces).
- `herdr config check` — validate `config.toml`.

## Gotchas

- `pane run` submits text+Enter atomically; `agent prompt` also submits (bracketed-paste + encoded Enter) on the agent surface and rejects agents already at an approval dialog. `herdr-msg` checks the target once after send and reports `target_status`. If still idle, receipt is `unconfirmed`.
- `recent-unwrapped` is better than `recent` when matching command output; `detection` is the plain-text snapshot Herdr uses for agent detection.
- Herdr sets `HERDR_ENV=1`, `HERDR_PANE_ID`, `HERDR_WORKSPACE_ID`, `HERDR_TAB_ID`, `HERDR_SOCKET_PATH` in panes.
- `--lines` cannot recover rows that left the terminal's alternate screen; if a read stalls, ask the agent to write its full response to a file and reply with the path.
- After `pane move`, the pane receives a new workspace-qualified ID; re-read IDs from the JSON result instead of reusing the old one.
- Long diffs/logs: write a file path into the message; do not paste huge blobs into the peer prompt.
- `herdr-msg` resolves targets by unique agent name, pane_id, or terminal_id. If several agents share a label (e.g. two `codex` panes) the label is ambiguous and resolution fails with the matching pane_ids listed — resend with a pane_id from `herdr agent list`.
- Request-to-self is refused by default (`--allow-self` to override).
- Keep headers one line; put status and findings in the **body** (`DONE: …` / `BLOCKED: …`).