Agents

Herdr is built for running more than one coding agent at a time. Each agent stays in a real terminal pane with its shell, logs, prompts, and running processes intact. Herdr tracks which panes contain agents, rolls their state up to tabs and workspaces, and lets you jump straight to the pane that needs attention instead of polling every terminal by hand.

To coordinate agents from scripts or from another agent, see Agent automation.

Supported agents

Agents get Herdr support in one of two ways: Herdr supports them, or they support Herdr themselves. Either way you see each agent’s idle, working, and blocked state, get notified when it finishes or needs you, and can wait on it from scripts.

Other agents still run normally in Herdr panes. They just show up as plain terminals.

Supported by Herdr

Herdr recognizes these agents and reads their state from what they draw on screen. To get the same session back after a Herdr server restart, install the agent’s integration with herdr integration install <name>. See Integrations for what each one installs.

Agent	Integration	Notes
Claude Code	claude
Codex	codex
GitHub Copilot CLI	copilot
Cursor Agent CLI	cursor
OpenCode	opencode	also reports state
Pi	pi	also reports state
OMP	omp	state requires the integration
Droid	droid
Devin CLI	devin
Kimi Code CLI	kimi	also reports state
Kilo Code CLI	kilo	also reports state
Hermes Agent	hermes
Qoder CLI	qodercli
Qwen Code	qwen
Letta Code	letta	CLI install only
MastraCode	mastracode	state requires the integration
Grok CLI	grok
Antigravity CLI	antigravity-cli
Amp	none	state only
Kiro CLI	none	state only
Maki	none	state only
Gemini CLI	none	state only, less tested
Cline	none	state only, less tested

Supported by the agent

These agents report their own state to Herdr. There is nothing to install; run them in a Herdr pane.

• Command Code
• Crush
• Kiro CLI
• Muse Code
• Prime Agent

An agent that also reports its resume command comes back in the same session after a Herdr server restart.

If you build a coding agent, Add Herdr support to your agent shows how to join this list. It takes a few calls to Herdr’s CLI or socket, and no change to Herdr.

How status works

For agents Herdr supports, Herdr finds the agent’s process in each pane and reads the live bottom of the pane, not the part you scrolled to. Rules in a detection manifest decide whether that screen means idle, working, or blocked. When an integration also reports state, Herdr uses those reports instead of reading the screen.

For agents that support Herdr, the agent’s own reports decide the state.

VMs and sandbox wrappers

On Linux and macOS, a host-visible wrapper can hide the real agent process from Herdr. Set HERDR_AGENT=<agent> on the wrapper command to tell Herdr which existing agent screen manifest to use. For example, run HERDR_AGENT=claude fence -- claude on Linux or HERDR_AGENT=claude nono run --profile claude-code -- claude on macOS. The hint applies only to that foreground process. Herdr cannot see it if you set it only inside a VM or container. Avoid exporting it globally unless every inherited foreground process should be treated as that agent.

Some restricted Linux runtimes do not expose a terminal foreground process group. Start the Herdr server with HERDR_PROCESS_DETECTION=child-groups to opt into direct child-process-group inference when native detection is unavailable. Native detection remains preferred, and the default native mode never performs this inference. The opt-in mode is best effort: a newer background job can be mistaken for the foreground job. The variable is read by the server and requires a restart; set it in the remote server environment rather than on an attaching client.

Blocked state

Blocked detection is deliberately strict for screen-manifest agents. Herdr only marks blocked when the live bottom-buffer snapshot matches known visible approval, question, or permission UI. If no manifest rule matches for a known agent other than Codex, Herdr falls back to idle and labels that fallback as default_known_agent_idle_fallback in explain output. Codex falls back to unknown because its title and composer can look the same during an active turn and after a response.

For those other agents, unusual new prompts may initially show as idle instead of blocked until Herdr learns that screen shape. The misclassification affects only the visible status and waits. It should not make Herdr send input or take destructive action.

For Codex, a visible spinner or live activity timer can establish working, and a visible approval prompt can establish blocked. When Codex’s terminal title shows no spinner, Herdr reports idle. Codex stays unknown only when no rule matches, for example when Codex sets no terminal title, and waits for idle or completion may then time out. Managed startup uses the initial composer only to determine when it can accept a prompt; that observation does not change turn status.

Detection manifests

Bundled manifests live inside Herdr. Herdr also checks herdr.dev for remote manifest updates and applies valid per-agent rule updates automatically without requiring a Herdr restart. Remote manifests are stored in Herdr’s state directory. Set [update] manifest_check = false to disable background remote manifest checks.

Local overrides can replace a remote or bundled manifest from the platform config directory:

~/.config/herdr/agent-detection/<agent>.toml

Local overrides always win. Without a local override, Herdr uses the newer compatible manifest between the cached remote manifest and the bundled manifest in the running binary. On debug builds, the same config helper may use a development directory such as herdr-dev. Invalid override files are ignored with a warning and Herdr falls back to the cached remote or bundled manifest for that agent.

Remote manifests patch detection rules for agents Herdr already knows how to identify. Adding a completely new agent still requires a Herdr binary update for process detection, labels, and integration behavior.

The running server loads active manifests into memory on startup. Automatic remote manifest updates reload that in-memory cache after new rules are written. Run herdr server update-agent-manifests to fetch remote manifest updates immediately and reload the running server. After editing a local override manually, restart Herdr or run herdr server reload-agent-manifests to apply the file to the running server.

Use herdr agent explain when a pane shows the wrong state:

herdr agent explain <target>
herdr agent explain --file screen.txt --agent codex --json

Live explain is evaluated by the running server, so it reflects the active manifest cache. The explain output shows the agent, final state, whether screen detection was skipped by a full lifecycle authority, manifest source and version, cached remote version, local override shadowing, remote update status, matched rule, visible evidence flags, matcher and region evidence for evaluated rules, skipped-update reason for transcript viewers, and the idle fallback reason when no rule matched.

Herdr can run inside tmux as the outer terminal environment. Agent detection does not inspect tmux sessions launched inside a Herdr pane. If a shell framework auto-enters tmux inside Herdr, Herdr sees tmux as the pane process instead of the agent behind it.

If your shell automatically attaches to tmux whenever TMUX is unset, update its startup rule to exclude Herdr panes. Reattaching the outer tmux session from inside a Herdr pane can recursively shrink the terminal and make it flicker. Add the HERDR_ENV check to your existing condition before it runs tmux:

if [[ -z ${TMUX:-} && ${HERDR_ENV:-} != 1 ]]; then
  tmux new-session -A -s my-session
fi

State rollups

The sidebar rolls state upward.

A blocked agent makes its pane, tab, and workspace look blocked. A working agent makes the workspace look active. A done agent stays visible until you view it.

This is the main Herdr workflow: start several agents, let them work in parallel, and use the sidebar to see which project needs a decision, which one is still running, and which one is ready to review.

Custom agent labels

You can rename an agent target for display:

herdr agent rename w1:p1 reviewer
herdr agent rename reviewer --clear

Targets accept a unique live agent name or the pane ID that currently hosts the agent. Terminal IDs and bare agent-kind labels are not accepted.

Custom status labels

Integrations report lifecycle state as semantic state only. Add display customization separately with pane metadata tokens.

herdr pane report-agent w1:p1 \
  --source custom:indexer \
  --agent docs-bot \
  --state working

herdr pane report-metadata w1:p1 \
  --source custom:indexer-display \
  --token summary=indexing

state controls waits, notifications, and rollups. The summary token is display-only and can be used as $summary in an Agent sidebar row.

Agent sidebar rows can also opt into terminal_title or terminal_title_stripped; neither appears in the default rows. The first shows the latest safety-normalized OSC 0/2 terminal title. The second removes one recognized leading activity or spinner glyph and following whitespace. Herdr owns these values on the server; they are ephemeral across a cold restart and remain independent of metadata titles and semantic agent state. Spinner animation can therefore update the raw title without producing a pane update when the stripped text stays the same.

Attach directly to an agent

Attach your current terminal to one agent terminal instead of the full Herdr UI:

herdr agent attach reviewer

Detach with ctrl+b q. Send a literal ctrl+b with ctrl+b ctrl+b.

Scroll with the mouse wheel or plain page up/page down. Normal input jumps back to the bottom.

Use --takeover if another direct attach client already owns input:

herdr agent attach reviewer --takeover

Use herdr terminal attach <terminal_id> when you want the same direct attach behavior for a non-agent terminal.