Herdr
Persistent open-source runtime that keeps your coding agents alive and reattachable via SSH from anywhere with a keyboard.
For developers who run multiple CLI coding agents and want them to survive their laptop's lid, Herdr is the pragmatic free pick. It's not an orchestrator or an IDE, and the Windows beta may still bite, but its agent-aware multiplexing over SSH offers real, no-cost durability. Compared to tmux, Herdr adds agent status and agent-to-agent control; compared to cloud services like Modal or Temporal, it keeps everything self-hosted with zero subscription and no telemetry.
Verified 1d ago · liveness 77/100 · cite: rightaichoice.com/tools/herdr
- Developers running multiple concurrent AI coding agents in parallel
- Power users needing persistent agent sessions across laptops and remote servers
- Terminal-first engineers wanting agent-aware multiplexing beyond tmux
- Teams collaborating via shared remote agent terminals on a self-hosted box
- Non-technical users who prefer graphical apps or browser interfaces
- Users needing built-in agent orchestration, RAG pipelines, or task routing
- Developers running only a single local agent with no persistence needs
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Skip Herdr if you don't live in a terminal, need built-in orchestration or RAG, run only one local agent with no persistence needs, or require a managed service with SLAs.
Self-hosting means you pay for the server hardware or VPS to run agents 24/7—Herdr itself is free, but your infrastructure costs can add up for heavy parallel workloads.
Herdr is $0/mo for unlimited agents, sessions, and SSH reattachment—priced for individuals and self-hosters who avoid per-seat fees. Compared to Claude Code ($20/mo for Pro) or Codex ($20/mo), it's a free layer you run yourself. Enterprise teams needing managed orchestration should look at Temporal or Modal, which cost per execution, but for terminal-native developers, Herdr's $0 price beats tmux-plus scripts.
In short
Herdr — Persistent open-source runtime that keeps your coding agents alive and reattachable via SSH from anywhere with a keyboard. Best for Developers running multiple concurrent AI coding agents in parallel, Power users needing persistent agent sessions across laptops and remote servers, Terminal-first engineers wanting agent-aware multiplexing beyond tmux. Free to use.
What's new in Herdr
Checked yesterdayAcross the latest 4 updates: 1 feature update, 1 launch, 1 changelog entry and 1 news mention.
Ten agents, three clients, 95% less CPU
Herdr cut CPU usage by 95% by stopping sidebar animations and unnecessary repaints in busy environments.
Coding agents are becoming runtimes
Argues that agent CLIs need shared contracts for instructions, state, hooks, and terminal runtimes.
Live updates without killing your terminal processes
Server updates now replace while keeping pane processes alive, so your running agents aren't interrupted.
Herdr 0.6.3: session persistence, safer updates, and workspace navigation
Adds persistence paths for updates, server restarts, and larger sessions, plus live server replacement.
What people actually say about Herdr — is it worth it?
We ran a structured research pass across product reviews, community discussions, and post-purchase forum threads to surface the patterns vendors won't publish themselves. Below: the recurring strengths, the hidden costs people mention most, and the cohort that consistently regrets adopting this tool.
45 mentions across 2 sources (Hacker News, Lemmy) · researched Aug 19, 2026.
- +Persistent agents survive laptop close, reboot, and network drops.
- +Reattach from any SSH-capable device, including phone.
- +Real PTY per agent, not tmux/screen multiplexing fakes.
- +Visual agent status (working, blocked, idle) at a glance.
- +Agent-native JSON socket API for pane control and inter-agent prompts.
- −Steep learning curve for tmux/nvim veterans.
- −Windows support is beta and may be buggy (WSL issues).
- −Docs confusing about model provider support (e.g., Vercel AI gateway).
- −Missing customization options (colors/font/sizing) for daily-driver use.
- −Closed-source CLI/SaaS components block community PRs.
- • Potential future paid features if YC drives a GUI/SaaS product (community speculation).
- • Self-hosting requires a persistent server (e.g., your own box) with SSH setup.
Viability Score
How well maintained and how widely used is Herdr? Built from what the vendor actually publishes (docs, changelog, tutorials, integrations, pricing), whether the site is live, and how much real users discuss it. How we calculate this
Last calculated: September 2026
How we score →Key Features
- Persistent agent server across sleep, close, and reboot
- Reattach from any device via SSH, including phone
- Real PTYs—not tmux or screen multiplexing
- Per-pane status: working, blocked, idle
- Agent-native CLI and JSON socket API
- Agents can split panes, start each other, and prompt each other
- Session persistence across updates, restarts, and large sessions
- Live server updates replace without killing pane processes
- CPU optimizations cut repaints by up to 95%
- Detects 21 agent CLIs out of the box
- Supports Claude Code, Codex, Cursor, opencode, Grok, Copilot, Hermes
- Self-hosted open-source Rust binary, Apache 2.0
- No account or telemetry required
- Installs via curl, Homebrew, or Nix
- Runs on macOS, Linux, Windows (beta)
About Herdr
Herdr is a free, Apache-2.0 runtime that runs your AI coding agents as persistent background servers, so closing your laptop, dropping the network, or rebooting doesn't kill them. It's built for terminal-first developers who juggle multiple agents like Claude Code, Codex, Cursor, opencode, Grok, Copilot, and Hermes, and who need session survival and remote reattachment without a cloud subscription. With 21 agent CLIs detected out of the box and 909 community plugins, Herdr integrates with existing workflows rather than replacing them. The tool is a single Rust binary for macOS, Linux, and Windows (beta), installable via curl, Homebrew, or Nix. It uses real PTYs—not tmux/screen multiplexing—so agents behave exactly as they would in a native terminal. A TUI shows every pane's status (working, blocked, idle) at a glance, and the CLI and JSON socket API give agents the same controls, letting them split panes, start each other, and prompt each other. Sessions persist across updates and restarts, and live server replacement keeps pane processes alive during maintenance. Recent releases (0.8.2) added session persistence for updates and large sessions, plus CPU optimizations that cut repaints by up to 95% in busy environments—meaning less wasted resources on idle animation. Herdr joined Y Combinator in August 2026, but the core remains open and self-hosted, with no account or telemetry. Positioned between tmux (which persists terminals but ignores agents) and per-machine GUI managers, Herdr is an agent-aware multiplexer you host yourself. It's free to use, so it's a low-risk addition for anyone already living in the terminal.
Behind the Verdict
Herdr is a rare open-source tool that targets a specific, growing pain: coding agents that die when your terminal session ends. The core value is persistence—sessions survive sleep, network drops, and reboots, and you can reattach from any device via SSH, even a phone. That alone is a big win for anyone running long, unattended agent tasks like a 6-hour data backfill. The agent status view (working/blocked/idle) saves real time: you don't hunt pane by pane for the agent waiting on your input. And the agent-native CLI/socket API means agents can coordinate—split panes, start each other, prompt each other—which is a step beyond static multiplexing. Weaknesses: it's a runtime, not an orchestrator. No workflow memory, RAG, or task routing—you bring your own agent CLIs. Windows support is still beta, and you manage your own security and uptime. As it joins Y Combinator, watch for pricing changes, though the core is Apache-2.0 and self-hosted, so lock-in is minimal. If you're a single-agent local user, the persistence benefits are small; if you're a team needing managed SLAs, you'll look elsewhere. For terminal-heavy developers running 2+ agents, it's a no-cost tool worth trying this week.
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Real-world workflow fit
Concrete scenarios for the personas Herdr actually fits — and what changes day-one when you adopt it.
You run Claude Code for feature work, Codex for a data backfill, and opencode for a refactor. You close your laptop and head out.
Outcome: All three agents keep running on the Herdr server. You SSH in from your phone later, see who's blocked and who's done, and reattach to the one waiting on you.
You rent a $20/mo VPS, install Herdr, and SSH in to start a long-running migration agent that runs for hours.
Outcome: The agent survives network drops and reboots. You reattach from any laptop with a keyboard, check status, and hand off mid-task without losing state.
Two engineers share a dev box to run agent CI jobs. They both attach to the same Herdr server to watch progress.
Outcome: Both see the same panes and statuses. Agents can start each other and prompt each other, so handoffs happen without firing keystrokes blindly.
Use Cases
- Run three different coding agents simultaneously on separate projects from one terminal.
- SSH into a remote build server and start a long-running agent session, then close your laptop and reattach from your phone later.
- Monitor agent progress at a glance – see which agents are blocked, working, or done without switching windows.
- Develop and test a live handoff feature where a server replacement does not interrupt running agent terminals.
- Use the persistent server to keep an agent working on a long-running task (e.g., code migration) while you switch devices.
- Leverage the API to integrate Herdr with your own CI/CD pipeline for automated agent runs.
Models Under the Hood
as of 2026-08-26
Limitations
- Herdr is a terminal runtime for coding agents, not an agent orchestration platform; it does not manage agent workflows, memory, or RAG.
- It relies on external agent CLIs like Claude Code and Codex rather than including its own AI models.
- The Windows version is currently in beta, as noted on the site.
- The tool is self-hosted and open-source under Apache 2.0, so security and uptime depend on your own infrastructure.
as of 2026-09-02
Verification history
We have re-verified Herdr 8 times since . Each pass re-reads the vendor's own pages and re-checks every listed field against that evidence; passes where nothing had changed are marked as such.
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-checked, vendor evidence unchanged
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
Showing the 6 most recent of 8 verification passes.
Free to cite with attribution — this page re-verifies continuously.
12-month cost
Project the real annual outlay, including the implied monthly cost when only an annual tier is published.
Vendor list price only. Add-on usage, seat overages, and contract minimums are surfaced under Hidden costs & gotchas.
Plans compared
For each published Herdr tier: who it actually fits, and what it adds vs. the previous tier. Cross-reference the cost calculator above for projected annual outlay.
Stable
$0/mo
Ideal for
Solo developer or small team on a self-hosted box needing unlimited agents and sessions at zero cost, with SSH reattachment and no telemetry.
What this tier adds
Starting tier and only tier—free forever with all features: persistent server, real PTYs, agent status, CLI/socket API, 21 agent detections, 909 plugins.
Where the pricing makes sense
The company stage and team size where Herdr's pricing actually pencils out — and where peers do it cheaper.
Herdr is $0/mo for unlimited agents, sessions, and SSH reattachment—priced for individuals and self-hosters who avoid per-seat fees. Compared to Claude Code ($20/mo for Pro) or Codex ($20/mo), it's a free layer you run yourself. Enterprise teams needing managed orchestration should look at Temporal or Modal, which cost per execution, but for terminal-native developers, Herdr's $0 price beats tmux-plus scripts.
Setup time & first value
How long it actually takes to get something useful out of Herdr — broken out by persona, not the marketing-page minute.
For a terminal user: install via curl and start your first agent in under 5 minutes—the server auto-detects your agent CLIs. For tmux users: 10-15 minutes to map your ctrl+b muscle memory and set up SSH reattachment. For a team: 30-60 minutes to configure the shared server and permissions.
Switching to or from Herdr
How to bring data in from common predecessors and how to get it back out — written for the switcher, not the buyer.
- →From tmux: Herdr mirrors tmux keybindings (prefix ctrl+b), so panes, detach, and reattach feel familiar—just add agent status and socket API.
- →From screen: Use screen's session resume logic and map to Herdr's detach/reattach; your scripts need minor changes to use herdr CLI.
- →From cloud agent services (e.g., Modal): Export your agent commands and run them inside Herdr panes on your own hardware, keeping the same agent CLIs.
- ↗To tmux: Export your agent commands and run them in tmux—you lose agent status and the socket API but keep persistent terminals.
- ↗To screen: Similar to tmux—persistent terminals but no agent awareness.
- ↗To a managed orchestrator (e.g., Temporal): If you need scheduled, durable execution, move your agent jobs into that platform; Herdr's SSH reattachment won't map directly.
Integrations
Resources & Guides
- Documentationherdr.dev
Docs · Herdr
Full product docs from herdr.dev
- Resourceherdr.dev
Agent Guide · Herdr
Helpful link from herdr.dev
- Documentationherdr.dev
Install · Herdr
Full product docs from herdr.dev
- Quickstartherdr.dev
Quick Start · Herdr
Get up and running fast from herdr.dev
- Conceptsherdr.dev
Concepts · Herdr
Core ideas explained from herdr.dev
- Documentationherdr.dev
Keybindings · Herdr
Full product docs from herdr.dev
- Documentationherdr.dev
Agents · Herdr
Full product docs from herdr.dev
- Documentationherdr.dev
Session State · Herdr
Full product docs from herdr.dev
- Documentationherdr.dev
Configuration · Herdr
Full product docs from herdr.dev
- API Referenceherdr.dev
Api · Herdr
Methods, params, types from herdr.dev
Tutorials & Learning
Official links
Featured Head-to-Head Comparisons
Herdr vs Temporal Ai
Temporal AI and Herdr serve fundamentally different needs: Temporal is a production-grade orchestration platform for mission-critical, multi-step AI workflows that require durability and reliability; Herdr is a lightweight terminal multiplexer for running several AI coding agents side-by-side with session persistence. Choose Temporal if you need to build robust agent pipelines or microservices orchestration; choose Herdr if you want a 'tmux for AI agents' to manage multiple coding assistants from one terminal.
Herdr vs Voyage Ai
These tools address completely different problems: Voyage AI provides domain-specialized embedding and reranker models for enterprise RAG, while Herdr is a free, open-source terminal multiplexer for running multiple AI coding agents persistently over SSH. Choose Voyage AI if you need high-accuracy retrieval on finance/legal documents; choose Herdr if you manage multiple coding agents and want session persistence across devices.
Herdr vs Spider Cloud
Herdr and Spider Cloud serve completely different needs. Herdr is a terminal multiplexer for running multiple AI coding agents side-by-side with persistence over SSH – perfect for power users who live in the terminal. Spider Cloud is a web scraping API that feeds real-time data to AI agents and RAG pipelines. There's no overlap; choose based on whether you manage agents or need to ingest web data.
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Frequently Asked Questions
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