OmniscioGuidesRunning 10-20 coding agents at once
What do you use to run 10‑20 coding agents at once?
Short answer: give each agent its own git worktree, run them somewhere that survives a closed window, and use a tool that shows which one is waiting on you. Herdr if you live in a terminal, Orca or T3 Code for an open-source desktop app, Omniscio for one app across projects with an inbox.
Two choices decide this, and most threads answer only the first. The harness is the agent that reads and edits your code: OpenCode, Pi and Hermes are three of them. The cockpit is what holds ten or twenty at once, and that is where a setup usually falls apart. Herdr, Orca, T3 Code and Omniscio each answer the second question differently. We ran twelve writers at once in a single working copy, then twelve real Claude Code sessions with a worktree each, on one Linux machine, and the difference between those runs is most of the answer. Omniscio is the one we make, so its section is marked as ours.
- OpenCodeNeeds You
- Claude CodeRunning
- PiRunning
- HermesRunning
- CodexError
Last tested on Claude Code 2.1.302, October 17, 2026. By the Omniscio team. Updated .
What breaks first when you run 10-20 agents at once?
Files. Two agents in one working copy write the same file, the last write wins, and nothing is left to show the first one existed. Twelve do it faster, and the first capture below is that run. A git worktree per session is the fix: a real directory on its own branch, so each session changes a file that no other session can reach.
Attention. Twenty sessions produce twenty streams of output, and the useful question stops being what each one is doing and becomes which one is waiting on you. A list that does not sort by that turns triage into a scroll; an inbox that does turns it into a queue. Herdr reads every pane and marks each agent working, blocked or idle, Orca shows a notification and unread state when an agent finishes or needs attention, and T3 Code sends phone alerts and, with its beta Working section turned on, returns those threads to the top of its list.
Terminals. A session lives inside a terminal, and a plain terminal takes the session with it when the window closes. Herdr answers that with a background server that owns the terminals, Orca and T3 Code with apps on a phone, and Omniscio with desktop notifications and a phone browser view whose public internet access is off by default.
What we ran ourselves
Twelve is the low end of the range in the question, so every run below is twelve at once. Each is a real run in a throwaway directory on our Linux test machine on October 17, 2026, with Claude Code 2.1.302, git 2.43.0 and tmux 3.4. Agent replies are left out; every other line is what the program printed, apart from the cuts each capture declares.
Twelve writers, one working copy
One repository, twelve processes started at the same moment, each told to write the same file, and no working copy of its own for any of them.
$ git init -q /tmp/cap1
$ cd /tmp/cap1
$ printf '<h1>v1</h1>\n' > index.html
$ git add index.html
$ git -c user.name=capture -c user.email=capture@example.com commit -qm "first pass"
$ for i in $(seq 1 12); do ( printf '<h1>writer %s</h1>\n' "$i" > index.html ) & done
$ wait
$ cat index.html
<h1>writer 12</h1>
$ git status --short
M index.html
$ git diff
diff --git a/index.html b/index.html
index f4bbc8a..ee1dcde 100644
--- a/index.html
+++ b/index.html
@@ -1 +1 @@
-<h1>v1</h1>
+<h1>writer 12</h1>The cat shows writer 12 on disk. The eleven writes before it are gone, git reports one changed line against the last commit, and nothing in the log says twelve processes tried. Which writer won is whichever wrote last; a second run can end on a different number.
Captured on our Linux test machine on October 17, 2026, with git 2.43.0. The lines starting with $ are the commands, in the order they ran, and every other line is what the program printed. The shell's own job-completion notices are left out, and nothing else is trimmed.
Twelve Claude Code sessions, twelve worktrees
Now twelve real Claude Code sessions, each given its own worktree before it starts. Every prompt asks for a one-line edit to the same file, in its own copy.
$ git init -q /tmp/cap2/repo
$ cd /tmp/cap2/repo
$ printf '<h1>v1</h1>\n' > index.html
$ git add index.html
$ git -c user.name=capture -c user.email=capture@example.com commit -qm "first pass"
$ for i in $(seq 1 12); do git worktree add -q /tmp/cap2/s$i -b session-$i; done
$ time ( for i in $(seq 1 12); do ( cd /tmp/cap2/s$i && claude -p "Overwrite index.html so that its contents are exactly: <h1>written by session $i</h1> followed by a single newline" --permission-mode acceptEdits > /tmp/cap2/log$i 2>&1 ) & done; wait )
real 0m12.953s
user 0m12.719s
sys 0m2.049s
$ for i in $(seq 1 12); do cat /tmp/cap2/s$i/index.html; done
<h1>written by session 1</h1>
<h1>written by session 2</h1>
<h1>written by session 3</h1>
<h1>written by session 4</h1>
<h1>written by session 5</h1>
<h1>written by session 6</h1>
<h1>written by session 7</h1>
<h1>written by session 8</h1>
<h1>written by session 9</h1>
<h1>written by session 10</h1>
<h1>written by session 11</h1>
<h1>written by session 12</h1>
$ git worktree list
/tmp/cap2/repo ba78d9e [master]
/tmp/cap2/s1 ba78d9e [session-1]
/tmp/cap2/s10 ba78d9e [session-10]
/tmp/cap2/s11 ba78d9e [session-11]
/tmp/cap2/s12 ba78d9e [session-12]
/tmp/cap2/s2 ba78d9e [session-2]
/tmp/cap2/s3 ba78d9e [session-3]
/tmp/cap2/s4 ba78d9e [session-4]
/tmp/cap2/s5 ba78d9e [session-5]
/tmp/cap2/s6 ba78d9e [session-6]
/tmp/cap2/s7 ba78d9e [session-7]
/tmp/cap2/s8 ba78d9e [session-8]
/tmp/cap2/s9 ba78d9e [session-9]Every write survived, in twelve directories on twelve branches, and git worktree list shows thirteen entries because the repository itself is one of them. All twelve worktrees sit at the same commit as the repository, and every one holds a different write. That is what Omniscio's worktree switch turns on.
Captured on the same machine and day, with Claude Code 2.1.302 and git 2.43.0. The time command is long and wraps here; it ran as one line. Each session's reply went to its own log file and is not shown; the real, user and sys lines after it are the shell's own timing.
Twelve sessions with nothing attached
A cockpit is only useful if the sessions outlive the window, so the third run gives twelve terminal sessions a command each and no terminal at all.
$ mkdir -p /tmp/cap3
$ for i in $(seq 1 12); do tmux new-session -d -s agent-$i -c /tmp/cap3 "sleep 8; echo agent-$i >> /tmp/cap3/out.log"; done
$ tmux ls
agent-1: 1 windows (created ...)
agent-10: 1 windows (created ...)
agent-11: 1 windows (created ...)
agent-12: 1 windows (created ...)
agent-2: 1 windows (created ...)
agent-3: 1 windows (created ...)
agent-4: 1 windows (created ...)
agent-5: 1 windows (created ...)
agent-6: 1 windows (created ...)
agent-7: 1 windows (created ...)
agent-8: 1 windows (created ...)
agent-9: 1 windows (created ...)
$ tmux ls | wc -l
12
$ sleep 10
$ wc -l /tmp/cap3/out.log
12 /tmp/cap3/out.log
$ sort /tmp/cap3/out.log
agent-1
agent-10
agent-11
agent-12
agent-2
agent-3
agent-4
agent-5
agent-6
agent-7
agent-8
agent-9Twelve terminals existed with nothing attached to any of them, and every one wrote its marker while nobody was watching. That is what the tools below mean when they talk about closing the lid and coming back.
Captured on the same machine and day, with tmux 3.4. The creation timestamps in the tmux ls lines are elided with ...; nothing else is trimmed, and the server was killed at the end of the run.
Not reproduced: the interface of Herdr, Orca, T3 Code, Pi, OpenCode and Hermes Agent. We do not install rival products on our test machine, so nothing here describes any of their screens, menus or keystrokes. Every statement about them rests on their own site, documentation, README or licence file, and each one is named in the Sources section.
Which harness should each agent run?
A harness is the agent itself: the program that takes a prompt, reads your files and writes the change. These three work differently, and Omniscio runs all of them, so this choice is not a choice about the cockpit.
Claude Code and Codex are two harnesses many readers already run. Herdr detects both, Orca lists both, T3 Code works with both, and Omniscio supports both. OpenCode, Pi and Hermes are harnesses themselves rather than a way to run Claude Code.
OpenCode
OpenCode calls itself the open source AI coding agent and runs in a terminal, an IDE or a desktop app. It ships free models and connects to any provider, with more than 75 through Models.dev including local models, and it says it does not store your code or context data, so it can run where that matters. It installs from one script and is MIT licensed.
It is the better pick if you want a free harness with more than 75 providers through Models.dev and you are happy in a terminal.
Pi
Pi calls itself a minimal agent harness, an extensible one you can make your own. It ships with defaults and leaves out sub-agents and plan mode on purpose, and it does not include a built-in permission system for restricting filesystem, process, network or credential access. It runs interactively, in print or JSON, over RPC, or through a TypeScript SDK, with more than 15 providers and hundreds of models. It is MIT licensed and installs from one script or npm.
It is the better pick if you want a small harness you can take apart and rebuild, and you do not want sub-agents or plan mode in the box.
Hermes Agent
Hermes Agent, from Nous Research, calls itself the self-improving AI agent: an autonomous agent that gets more capable the longer it runs. It creates and improves its own skills during use and keeps memory across sessions. It reaches you through a CLI and a gateway for Telegram, Discord, Slack and WhatsApp, which its docs count as 20+ platforms from one gateway, and it works with Nous Portal, OpenRouter, OpenAI or any endpoint. It is MIT licensed.
It is the better pick if you want an agent with memory and skills that can reach you in a chat app rather than only in a terminal.
Which tool actually holds 10-20 of them?
Here the tools differ in what they are built around rather than in quality. One is an agent runtime in the terminal, one a desktop environment, one a control surface over your existing agents, and one the app we make.
Scroll sideways for T3 Code and Omniscio.
| Herdr | Orca | T3 Code | Omniscio | |
|---|---|---|---|---|
| What it is | An agent runtime: a background server that owns the terminals your agents run in, with a CLI and socket API agents can drive. | A desktop environment for agents, with terminals, diffs, a browser and worktrees in one app. | An open-source control plane over the agents already on your machine. | A desktop app that runs many sessions at once, on several engines, across projects. |
| Agents it runs | 22 detected out of the box, including Pi, OpenCode, Hermes, Claude Code, Codex, Cursor and Copilot. | Any CLI agent; its README lists more than 30 by name, with the main ones preconfigured. | Claude Code, Codex, Antigravity, OpenCode, Cursor and Grok, on subscriptions you already hold. | Any model, any harness: Claude Code, Codex, OpenCode, Devin, Pi and Hermes all supported. |
| Isolation | A terminal pane per agent; its own pages do not describe a git worktree per agent. | Every task in its own isolated git worktree. | Every agent thread writes to its own branch. | A worktree per session, off until you turn it on, for one session, a project or the whole app. |
| Finding the one that needs you | Reads every pane and marks each agent working, blocked or idle. | Notifications and unread state when an agent finishes or needs attention. | Phone alerts when an agent finishes, fails or needs approval, and, with its beta Working section turned on, those threads return to the top of the list. | An attention-first inbox where needs-you sessions sort first. |
| Away from the desk | A background server that survives a closed lid or a dropped network, with machines added over SSH. | A companion app for iOS and Android, and remote boxes with auto-reconnect. | Apps for iOS and Android beside the desktop build. | Desktop notifications, and a phone browser view over a paired connection, with public internet access a switch that is off by default. |
| Cost and licence | Apache 2.0 licensed. | Free and open source under MIT. | Free and open source under MIT. | Free covers 8 projects and 10 sessions at once; Pro is $20 a month or $192 a year. |
Every cell about another tool quotes or closely paraphrases its own site, documentation or README, read on October 17, 2026. Where a cell says a tool does not describe something, that is a search of its own pages, and the search terms are recorded in the ledger beside this page.
Where is each one the better pick?
None of these is the wrong answer, and the work you do decides it.
- Herdr, if you live in a terminal and want twelve sessions that survive a closed laptop.
- Orca, if you want a desktop environment with worktrees, a browser and remote boxes, plus a phone companion.
- T3 Code, if you want a control surface over subscriptions you already pay for, and you can live with an early project; its own README says to expect bugs.
- OpenCode, if you want a free harness with more than 75 providers through Models.dev and a terminal-first flow.
- Pi, if you want a minimal harness to extend yourself, without sub-agents or plan mode built in.
- Hermes Agent, if you want memory and skills, and a way to reach the agent from a chat app.
- Omniscio, if you want a desktop app on Windows, macOS and Linux that runs any of those harnesses, with an inbox for the sessions that need you and per-session worktrees when you want them. It is not open source, and more than ten sessions at once needs Pro.
What does Omniscio do with twelve sessions?
Omniscio is the desktop app we make, so read this section with that in mind. It runs many sessions at once, across projects side by side, and installs on Windows, macOS and Linux. The agent underneath is your choice: any model and any harness, so one session can be OpenCode while the next is Pi or Claude Code.
Worktree isolation is the mechanism from the second capture, as a switch. It gives a session its own branch and working directory, so twelve sessions editing one repository do not write over each other, and it is off until you turn it on, per session, per project or for the whole app. Reviewing what comes back is the other half: the diff viewer shows uncommitted changes with an on-demand summary of what a file's diff does.
Sessions carry statuses, and the ones that need a person float above the ones that do not. They land in a single attention-first inbox, desktop notifications reach you while you are away from the app, and a phone browser view over a paired connection is there when a run needs to reach you further away.
There is a hard spending cap per session, which stops that session when its cost crosses the limit. More than ten sessions at once is the Pro side of the line: $20 a month or $192 a year.
How we tested
We ran Claude Code 2.1.302 on October 17, 2026, and read every source cited at the bottom of this page the same day. The captures in "What we ran ourselves" are real runs in throwaway directories under the temp directory on our Linux test machine, and every line of a program's own output is pasted as it printed, apart from the cuts each capture declares.
Agent replies are left out of every capture. What the captures show is the effect on disk and in the process table, which is the part that proves the point.
If a step here does not match what you see, the tools' own pages outrank ours. T3 Code's README says the project is very early, Pi changes and extends quickly, and Herdr detects 22 agents today, so read each project's own pages before you trust a copy of this page from a few months back.
Sources
Every claim about another tool on this page rests on one of these, and the date beside each one is the day we read it.
- T3 Code: its site, for the headline, the list of harnesses, the branch per thread, the platforms, and the free and MIT statements; its README, for the harness control surface description, the subscriptions it works with, the install commands, and the early-project warning; its docs (mobile notifications, thread sidebar) for the phone alerts and the beta thread re-sorting. Read October 17, 2026.
- Herdr: its site, for the agent runtime description, the background server, the 22 agents, the working, blocked and idle states, the socket API, the install commands, Apache 2.0 and the SSH machines, and its docs index for the CLI and socket API. Read October 17, 2026.
- Orca: its README, for the agent development environment description, the side-by-side worktrees, any CLI agent, the more than 30 agents named, the isolated worktree per task, the fan-out comparison, the notification and unread state, and the MIT licence; its site for the platforms, the remote box and the mobile companion. Read October 17, 2026.
- Pi: its site, for the minimal harness description, the features it skips, spawning through tmux, the four modes, the providers, the install command and the MIT licence; its README for the absence of a built-in permission system. Read October 17, 2026.
- OpenCode: its site, for the open-source agent description, the surfaces it runs in, the free models and providers, the 75 through Models.dev, the privacy statement and the install command; its licence file for MIT. Read October 17, 2026.
- Hermes Agent: its documentation, for the self-improving description, the learning loop, the skills and memory, the CLI and gateway platforms, the providers, the MIT licence and the install commands. Read October 17, 2026.
- Omniscio's own pages: the features page, for concurrent sessions, engines side by side, the attention-first inbox and needs-you sorting, desktop notifications, worktree isolation running per session once it is turned on, the cap per session, the diff viewer, and the phone browser view. Read October 17, 2026.
- Omniscio: the homepage, for the harness line we quote. Read October 17, 2026.
- Omniscio: the download page, for the platforms it installs on. Read October 17, 2026.
- Omniscio: the pricing page, for Free covering 8 projects and 10 sessions at once and Pro at $20 a month or $192 a year. Read October 17, 2026.
All six products here ship often, so check each project's own release list before you commit to one.
Common questions
Do I need a different tool for each coding agent?
No. The agent and the tool around it are separate choices. Herdr detects 22 agents out of the box, Orca accepts any CLI agent that runs in a terminal, and Omniscio runs Claude Code, Codex, OpenCode, Devin, Pi and Hermes.
How many agents can one machine run at once?
We ran twelve Claude Code sessions at once on one Linux machine and all twelve finished their edit, with every write surviving, in about 13 seconds. The number is set by memory, CPU and the rate limits of the accounts behind the sessions rather than by the tool, which is why isolation and attention matter more than the count.
Do the sessions share one working copy?
Only if you leave them in one. A git worktree gives a session its own branch and directory. In Omniscio that is a per-session switch that is off until you turn it on, for one session, a project or the whole app.
Which of these is free?
Herdr is Apache 2.0, Orca and T3 Code are free and open source under MIT, and Pi, OpenCode and Hermes Agent are MIT licensed. Omniscio has a free tier that covers 8 projects and 10 sessions at once, and Pro at $20 a month or $192 a year.
Is Omniscio the same kind of tool as Herdr or Orca?
Partly. All three hold many agents at once, but Omniscio is a desktop app built around an inbox across projects, where Herdr is an agent runtime in the terminal and Orca is built around worktrees. The harnesses do not change; what changes is the window you drive them from and where the sessions wait for you.
Related pages
How to run multiple Claude Code sessions at once
The Claude Code half of this question: isolation, worktrees, and the mistakes that cost you an afternoon.
A Claude Squad alternative with a GUI and Windows support
Claude Squad is an open-source terminal tool. We ran the isolation it relies on, and compared it with a desktop app.
Conductor vs Claude Squad
Two tools doing the same job in opposite shapes, checked against both projects' own docs.
Claude Code cost calculator
What twenty agents cost before you start them, from the tokens you expect each one to use.
Run many coding agents in parallel
Omniscio installs on Windows, macOS and Linux, and gives each session its own branch and working directory once you switch that on.