herdr is a background runtime that keeps coding-agent terminals and sessions running, even when a computer disconnects or restarts. It lets people and agents manage, inspect, and reconnect to sessions through a terminal interface or SSH while using tools such as Claude Code and Codex. The catalogue add-ons extend its panes and workflows.
Borrowing it
Nothing to install: this file belongs to herdrdev/herdr. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/herdrdev/herdr/master/.agents/skills/herdr-throwaway-repro/SKILL.mdgit clone --depth 1 https://github.com/herdrdev/herdrWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/herdrdev/herdr/herdr-throwaway-repro)<a href="https://agentmods.dev/skills/herdrdev/herdr/herdr-throwaway-repro"><img src="https://agentmods.dev/badge/skills/herdrdev/herdr/herdr-throwaway-repro/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/herdrdev/herdr/herdr-throwaway-repro"><img src="https://agentmods.dev/badge/skills/herdrdev/herdr/herdr-throwaway-repro.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00060 | $0.01965 |
| Opus 5.5 | $0.00024 | $0.00786 |
| Sonnet 5.5 | $0.00012 | $0.00393 |
| Haiku 4.5 | $0.00006 | $0.00197 |
Grade A, and why
herdr-throwaway-repro scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 191 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Herdr throwaway reproduction
Use a disposable named Herdr session when a reproduction needs a real Herdr server, panes, PTYs, agents, or socket API without risking the user's main session.
The temporary TUI only keeps the disposable session attached and supplies terminal geometry. Drive the reproduction from the parent session through Herdr's CLI/API. Do not manually operate the nested TUI unless the bug specifically requires client input.
Non-negotiable safety
- Never run the reproduction in the default session.
- Never stop, restart, delete, or kill the main Herdr server.
- Never use
pkill, broad process matching, or guessed PIDs for cleanup. - Create a unique session name. Never reuse or delete an unrelated named session.
- Create a new outer pane and close only that pane during cleanup.
- Read workspace, tab, pane, terminal, and agent IDs from command output. Never construct them.
- Use
/var/tmpfor reproduction directories and potentially large artifacts. - Do not approve destructive or unnecessary agent actions.
- Do not spend paid agent tokens without the user's approval. Use the requested low-cost model and the smallest useful prompts.
Learn the installed interface first
The installed binary is the authority. CLI syntax may have changed since this skill was written.
Confirm the caller is inside Herdr and inspect the relevant help before doing anything:
test "${HERDR_ENV:-}" = 1
herdr --version
herdr --help
herdr session
herdr pane
herdr agent
Inspect nested command help before using unfamiliar or potentially mutating commands. Do not run bare herdr for discovery because it launches or attaches the TUI.
Record which Herdr binary and version the reproduction tests. If testing a checkout build, follow the repository's instructions for running that build instead of silently substituting the installed binary.
Create the outer pane
Create a sibling shell pane in the current tab without moving focus. Use an available Herdr layout tool when the harness provides one. Otherwise use the installed pane split command after checking its help.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · +33 lines fde648f5d2f7
- 1mo ago First seen · 158 lines · 60 tokens per session scan A 4d66a4e26adb
herdr-throwaway-repro is a skill published in the GitHub repository herdrdev/herdr (46,030 stars, last pushed today), licensed Apache-2.0. It adds 60 tokens to every session and 1,965 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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