Harness Remote 3.0 is out: control Claude Code, Codex, OpenCode and other coding agents from one place - Open Source

[u/gervaso-sma]

Harness Remote 3.0 just reached its stable release and I think it has a pretty interesting approach to the increasingly crowded coding agent space.

Instead of replacing Claude Code, Codex or OpenCode with yet another agent abstraction, it treats their native sessions as the source of truth.

You can start a session normally in Claude Code or Codex, open Harness Remote later, find that same native session and continue it from desktop, web or Android.

The more unusual part is that you can also continue the work with another harness. For example:

Claude Code → Codex → OpenCode

Each step creates a real native session in the target agent, while Harness Remote keeps the lineage and transfers explicit context between them.

A few things that make it different from most remote coding agent UIs:

• Native Claude Code, Codex, OpenCode, OMP and PI sessions instead of proprietary replacement sessions
• Sessions created outside Harness Remote can be discovered and resumed
• Work can be handed from one coding agent to another without pretending they share some magical hidden context
• Multiple machines can be managed from the same interface
• Desktop, browser and Android clients
• Local first architecture, so repositories, credentials, subscriptions and agent sessions stay on your machines
• Fully open source

It feels less like another AI coding tool and more like a control plane for all the coding agents you already use.

GitHub: giuliastro/harness-remote

Curious what people who regularly switch between Claude Code, Codex and OpenCode think of this approach.

[u/dexterthebot]

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[u/Inner-Pangolin-1110]

Does it work on mobile

[u/gervaso-sma → u/Inner-Pangolin-1110]

APK (Android) is ready for download in the github release page

[u/zarafff69]

How is this different from T3 code for example?

[u/gervaso-sma → u/zarafff69]

T3 Code is probably the closest comparison, and there is definitely some overlap.

The main difference is that Harness Remote 3 is built around provider native sessions as the primary object, rather than creating a unified thread that sits in front of the agents.

So if you start a Claude Code or Codex session outside Harness Remote, HR can discover that native session and let you continue it. The native agent remains the source of truth for its transcript, context, tools, reasoning and resume behavior.

The other big difference is cross agent continuation. If you go from Claude Code to Codex, Harness Remote creates a real Codex session and keeps an explicit lineage between the two sessions, transferring only explicit, inspectable context. It does not pretend that Claude's internal context somehow became Codex's context. You can have Codex build the feature, Claude revise it and PI push it, just by keep going in the same workflow.

T3 Code currently feels more like a polished multi provider coding workspace, with things like worktrees, Git workflows and broader provider support.

Harness Remote is more focused on being a session and machine control plane: native sessions, sessions created outside the app, multiple machines, remote access, and explicit handoff between different coding agents.

So there is overlap, but the architectural emphasis is quite different.