splash

SplashCompareXum

Splash and Xum, compared.

Splash and Xum, formerly Mux, both run several coding agents at once from a desktop app or a browser. Xum, from Coder, runs its own agent loop against model provider APIs, in your checkout, a worktree, a container or a remote host. Splash drives vendors’ agents, such as Claude Code and Codex, over the Agent Client Protocol.

Checked 10 October 202667 sourcesNot affiliated with Coder

Splash

Helge Sverre

A desktop app for running several coding agents at once, each session in its project folder or its own git worktree. It drives agents over the Agent Client Protocol.12

splash.computer

Xum

Coder

Coder’s open-source app for running coding agents in parallel, each in its own workspace, from a desktop app, a browser or a CLI. It runs its own agent loop against many model providers’ APIs.3456

xum.cdr.dev

Side by side

SplashXum
The basics
What it is Desktop app, plus a headless server you open in a browser17 Electron desktop app, plus a CLI, a web UI server, a VS Code extension and an ACP bridge for editors8591011
Release status v0.2.1, early development112 v0.31.0 (9 October 2026), renamed from Mux; the docs say it is in early development, and the Windows build is alpha134148
License Open source (MIT)15 Open source (AGPL-3.0)316
Price Free17 Free; your model providers bill your usage. The optional Xum Gateway gives eligible GitHub users evaluation credits18614
Platforms macOS 14+ (Apple silicon and Intel), Windows 11 x64, Ubuntu 24.04 x6419 macOS (Apple silicon and Intel), Linux x64 and arm64 AppImages, Windows x64 (alpha); CLI and server through npm813
Built with Rust, with a Svelte 5 frontend in a webview, built on the Elyra framework20 TypeScript and React in Electron; the agent reaches models through Vercel AI SDK packages4218
Agents
Agents Ships launch commands for 20 agents, including Claude Code, Codex, Copilot, Gemini, Goose, OpenCode2223 Its own agent loop, with modes and sub-agents defined in Markdown; it doesn’t host Claude Code, Codex or other CLI agents42411
How it runs agents Agent Client Protocol over stdio, natively or through a pinned adapter for the vendor’s CLI222 Calls model APIs through Vercel AI SDK adapters, not a vendor CLI; bash and file tools run in the chosen runtime621425
Agent sign-in Who pays for the model You install and sign in to each agent’s CLI yourself; Splash runs it with that login23 API keys, a ChatGPT plan (Codex OAuth), GitHub Copilot, Xum Gateway credits or Coder’s AI Gateway; Claude plan login isn’t documented626272814
Account required Splash has no accounts; splash-server asks for a token it keeps in its data folder297 No Xum account; Xum Gateway sign-in with GitHub is optional, and xum server takes a bearer token or a GitHub login limited to one account149
Model and mode pickers Yes: Model, mode and effort pickers when the agent offers them30 Yes: Models from a dozen built-in providers, such as Anthropic, OpenAI, Google, Ollama and Bedrock, or custom endpoints; Plan and Exec modes6424
Permission requests When an agent asks before it acts Yes: Shown in the transcript and answered with the 1–9 keys; pending ones wait in Needs attention30 Partly: No per-command prompts documented; Plan mode asks multiple-choice questions and awaits plan approval, and experimental hooks can block commands3132
MCP servers Partly: Read-only list of MCP servers from Claude Code, Codex, Pi, Pool and Glue config files3033 Yes: Set globally in ~/.xum/mcp.jsonc with per-repo overrides, one instance per workspace; git-installed plugins add skills and MCP servers34
Working in parallel
Isolation per session Yes: The project folder, or a git worktree on its own branch per session30 Yes: Per workspace: the local checkout (no isolation), a git worktree, SSH host, Docker or Podman container, dev container or Coder workspace3536373839
Setup scripts and dev servers No: A worktree is a plain git checkout; Splash runs no setup scripts or dev servers3040 Yes: Runs .xum/init in each new workspace, plus archive and delete hooks; .xumignore copies files like .env. No dev-server handling documented41424344
What needs you Yes: One queue for permission requests, connection failures and finished turns, kept across restarts3045 Yes: Sidebar status per agent, written by a small model at set intervals, plus a marker when a model finishes44647
Notifications Yes: Notifies when a background session needs permission or finishes a turn; can be turned off4849 Yes: Native OS notifications for every response once you turn that on, or when the agent calls its notify tool; clicking one opens its workspace50
Agents handing off work One agent launching or messaging another No: Each session is one agent in one folder; sessions don’t hand work to each other130 Yes: Agents start sub-agents; Best of N runs several on the same task and combines their results2451
Scheduled tasks Agents that start without a prompt from you No: No scheduler; an agent starts when you create, continue or prompt a session20 Yes: Heartbeats prompt a workspace’s agent every 5 minutes to 24 hours, after idle time or on a fixed cadence; xum run starts tasks from scripts and CI3213552
Review and shipping
Review changes Yes: Latest response, failed tools and every changed file as a diff, with a box to send feedback30 Yes: Diff review pane and Immersive Review mode; the agent flags hunks to check, and line notes attach to the chat input45346545556
Create pull requests No: Shows the PR for a session’s branch and starts worktrees from PR heads; does not create PRs3057 Partly: The agent opens a PR when you ask and it has push credentials; no create-PR or merge button is documented44
GitHub Yes: Issues, pull requests and Actions runs across repositories, through the gh CLI3057 Yes: Finds each workspace’s PR through the gh CLI and shows its state, merge queue and CI checks, with a gh-stack dropdown for stacked PRs58596061
Where it runs
Remote access Yes: splash-server runs on the machine with your code; you use it in a browser over an SSH tunnel. Single user.7 Yes: xum server opens the web UI to other devices; the desktop app connects to remote servers; workspaces can run over SSH96225
Mobile app No: No mobile app; builds cover macOS, Windows, Ubuntu and a headless server19 Partly: No native app is documented; xum server’s web UI has a responsive layout for phones49
History and search
Existing agent history Conversations started outside the app Yes: Browse, preview and import conversations agents list over ACP, including ones started outside Splash3045 Not documented: Not documented; Xum’s own chats persist, their streams resume after restarts, and ACP editors can load them4763
Search transcripts Yes: Search titles, folders and saved transcript text, archived sessions included30 Not documented: Not documented; the command palette’s default mode is a workspace switcher64
Fork a conversation Partly: Experimental: fork the current conversation when the agent supports it, not from an earlier message3045 Yes: /fork opens a new workspace and branch from HEAD with the chat history, model and mode; uncommitted changes aren’t copied65

Where they differ

How agents connect

Xum runs its own agent loop, calling model APIs through Vercel AI SDK adapters, and does not host Claude Code, Codex or other external agents. It implements ACP as an agent, so editors such as Zed can start xum acp. Splash starts each vendor’s agent and speaks the Agent Client Protocol with it, natively or through an adapter.46211163222

Where agents run

Each Xum workspace picks a runtime: your checkout, a git worktree, a Docker or Podman container, a dev container, an SSH host or a Coder workspace. xum server serves the web UI to browsers and phones. Splash runs agents on your computer, in the project folder or a worktree, or under splash-server on a machine you reach over SSH.3538253994307

Price, accounts and license

Xum is free, AGPL-3.0-licensed and needs no Xum account. Models run on your own API keys, a ChatGPT plan or GitHub Copilot login, or Xum Gateway evaluation credits; the Coder provider uses the AI Gateway of your Coder deployment, which comes with a Coder Premium license. Splash is free and MIT-licensed, has no accounts, and runs each agent on that agent’s own login.181614626286615172923

Around the session

Xum builds tools around its agent: setup and cleanup hooks, sub-agents and Best of N, /fork, MCP servers and plugins, scheduled heartbeats, a xum run CLI for CI, and computer use in local workspaces on macOS and Linux X11. Splash centers on the conversations: a Needs attention queue, transcript search, importing sessions started elsewhere and a GitHub view across repositories.4142516534321355267304557

Which one fits

Splash may suit you if

  • You want Claude Code, Codex, Gemini CLI and other vendors’ agents side by side, each on its own CLI login.
  • You want each permission request shown in the transcript and pending ones gathered in one Needs attention queue.
  • You want to import conversations your agents started outside the app and search them with the rest.
  • You want a GitHub view of issues, pull requests and Actions runs across your repositories.

Xum may suit you if

  • You want one agent that works with a dozen model providers, Ollama or custom endpoints, on your own API keys.
  • You want workspaces in worktrees, containers, dev containers, SSH hosts or Coder workspaces, with an init script for each.
  • You want sub-agents, Best of N runs and forks of a workspace with its chat history.
  • You want a CLI for CI jobs such as GitHub Actions, and the same UI in a browser or on a phone.

Sources

Facts about Xum come from its public website, documentation and repositories as they read on 10 October 2026; we haven't confirmed each one by running Xum. Facts about Splash link to its source. Products change, so check the linked pages before deciding. Something wrong or out of date? Open an issue.

  1. 1 Splash README Splash on GitHub · github.com · checked 2026-10-09
  2. 2 Agent Client Protocol agentclientprotocol.com · agentclientprotocol.com · checked 2026-10-09
  3. 3 Introduction Coder · xum.cdr.dev · checked 2026-10-10
  4. 4 coder/xum coder/xum on GitHub · github.com · checked 2026-10-10
  5. 5 CLI Coder · xum.cdr.dev · checked 2026-10-10
  6. 6 Providers Coder · xum.cdr.dev · checked 2026-10-10
  7. 7 Splash README: Run as a web app over SSH Splash on GitHub · github.com · checked 2026-10-09
  8. 8 Install Coder · xum.cdr.dev · checked 2026-10-10
  9. 9 Server Access Coder · xum.cdr.dev · checked 2026-10-10
  10. 10 VS Code Extension Coder · xum.cdr.dev · checked 2026-10-10
  11. 11 ACP (Editor Integrations) Coder · xum.cdr.dev · checked 2026-10-10
  12. 12 Splash releases Splash on GitHub · github.com · checked 2026-10-09
  13. 13 Release v0.31.0 coder/xum on GitHub · github.com · checked 2026-10-10
  14. 14 Xum Gateway Coder · xum.cdr.dev · checked 2026-10-10
  15. 15 LICENSE Splash on GitHub · github.com · checked 2026-10-09
  16. 16 LICENSE coder/xum on GitHub · github.com · checked 2026-10-10
  17. 17 Download Splash splash.computer · splash.computer · checked 2026-10-09
  18. 18 Picks, Shovels, IDEs, and Mux Coder · coder.com · checked 2026-10-10
  19. 19 Splash README: Download the app Splash on GitHub · github.com · checked 2026-10-09
  20. 20 Splash README: How it works Splash on GitHub · github.com · checked 2026-10-09
  21. 21 package.json coder/xum on GitHub · github.com · checked 2026-10-10
  22. 22 src/agents/registry.rs Splash on GitHub · github.com · checked 2026-10-09
  23. 23 Splash README: Agents Splash on GitHub · github.com · checked 2026-10-09
  24. 24 Agents Coder · xum.cdr.dev · checked 2026-10-10
  25. 25 SSH Runtime Coder · xum.cdr.dev · checked 2026-10-10
  26. 26 src/common/constants/codexOAuth.ts coder/xum on GitHub · github.com · checked 2026-10-10
  27. 27 Release v0.16.1 coder/xum on GitHub · github.com · checked 2026-10-10
  28. 28 src/node/services/copilotOauthService.ts coder/xum on GitHub · github.com · checked 2026-10-10
  29. 29 Splash README: Build from source Splash on GitHub · github.com · checked 2026-10-09
  30. 30 Splash README: Features Splash on GitHub · github.com · checked 2026-10-09
  31. 31 Plan Mode Coder · xum.cdr.dev · checked 2026-10-10
  32. 32 Tool Hooks Coder · xum.cdr.dev · checked 2026-10-10
  33. 33 src/agents/customize.rs Splash on GitHub · github.com · checked 2026-10-09
  34. 34 MCP Servers Coder · xum.cdr.dev · checked 2026-10-10
  35. 35 Runtimes Coder · xum.cdr.dev · checked 2026-10-10
  36. 36 Local Runtime Coder · xum.cdr.dev · checked 2026-10-10
  37. 37 Worktree Runtime Coder · xum.cdr.dev · checked 2026-10-10
  38. 38 Docker Runtime Coder · xum.cdr.dev · checked 2026-10-10
  39. 39 Coder Runtime Coder · xum.cdr.dev · checked 2026-10-10
  40. 40 src/worktree.rs Splash on GitHub · github.com · checked 2026-10-09
  41. 41 Init Hooks Coder · xum.cdr.dev · checked 2026-10-10
  42. 42 Archive and Delete Hooks Coder · xum.cdr.dev · checked 2026-10-10
  43. 43 .xumignore Coder · xum.cdr.dev · checked 2026-10-10
  44. 44 Workspaces Coder · xum.cdr.dev · checked 2026-10-10
  45. 45 Splash README: Existing sessions and review Splash on GitHub · github.com · checked 2026-10-09
  46. 46 Release v0.25.0 coder/xum on GitHub · github.com · checked 2026-10-10
  47. 47 Why Parallelize? Coder · xum.cdr.dev · checked 2026-10-10
  48. 48 app/src/components/settings/General.svelte Splash on GitHub · github.com · checked 2026-10-09
  49. 49 app/src/lib/system.ts Splash on GitHub · github.com · checked 2026-10-09
  50. 50 Notifications Coder · xum.cdr.dev · checked 2026-10-10
  51. 51 Best of N Coder · xum.cdr.dev · checked 2026-10-10
  52. 52 GitHub Actions Coder · xum.cdr.dev · checked 2026-10-10
  53. 53 Release v0.22.0 coder/xum on GitHub · github.com · checked 2026-10-10
  54. 54 Release v0.12.1 coder/xum on GitHub · github.com · checked 2026-10-10
  55. 55 src/common/types/review.ts coder/xum on GitHub · github.com · checked 2026-10-10
  56. 56 src/browser/hooks/useReviews.ts coder/xum on GitHub · github.com · checked 2026-10-10
  57. 57 Splash README: GitHub view Splash on GitHub · github.com · checked 2026-10-09
  58. 58 src/browser/stores/PRStatusStore.ts coder/xum on GitHub · github.com · checked 2026-10-10
  59. 60 Release v0.28.2 coder/xum on GitHub · github.com · checked 2026-10-10
  60. 61 Release v0.13.0 coder/xum on GitHub · github.com · checked 2026-10-10
  61. 62 Release v0.28.5 coder/xum on GitHub · github.com · checked 2026-10-10
  62. 63 src/node/acp/agent.ts coder/xum on GitHub · github.com · checked 2026-10-10
  63. 64 Keyboard Shortcuts Coder · xum.cdr.dev · checked 2026-10-10
  64. 65 Forking Workspaces Coder · xum.cdr.dev · checked 2026-10-10
  65. 66 AI Gateway client configuration: Xum Coder · coder.com · checked 2026-10-10
  66. 67 Computer Use Coder · xum.cdr.dev · checked 2026-10-10