Using Claude Code with T3 Code

Run Anthropic's Claude Code inside T3 Code — install and auth, whether your Claude subscription works, skills in the composer, and recent Opus 5 model support.

Last reviewed 2026-07-27 · verified against the pingdotgg/t3code repo

Claude Code is the second major provider and receives steady attention in recent builds — Claude Opus 5 support and skills discovery both landed in July 2026 nightlies.

Setup#

npm i -g @anthropic-ai/claude-code
claude auth login
claude --version

Then launch T3 Code:

npx t3@latest

If claude --version fails, fix that before involving T3 Code — it launches this binary as a subprocess and cannot authenticate on your behalf.

Does my Claude subscription work?#

Yes. T3 Code is bring-your-own-key in the broad sense: it uses whatever your Claude Code CLI is already authenticated with. If claude auth login signed you in with a Claude subscription, T3 Code inherits that session. If you're on an API key, it uses the key.

There's no separate T3 Code billing, no account, and no proxy in between. Your usage counts against your Anthropic account exactly as it would from the terminal.

Skills in the composer#

Recent nightlies made Claude Code skills discoverable in the composer — you can find and invoke skills from the T3 Code interface rather than having to remember what's available.

This matters more than a small UI change usually would. Skills are one of the better parts of Claude Code, and discoverability is their weak point. Being able to browse them where you write the prompt is the difference between using them and forgetting they exist.

Model support#

Model selection is available in the composer, and recent builds added Claude Opus 5 support along with a restored model picker layout and a bolt icon for fast mode.

The useful pattern: switch models within a thread rather than starting over. Cheap and fast for exploration and boilerplate, more capable for the part that actually needs care — without losing the context you've built up.

Claude Code CLI vs Claude Code in T3 Code#

You get the same agent either way. T3 Code adds the surrounding workflow:

Nothing is taken away. Anything T3 Code does, you can still do in a terminal — which is a reasonable reason to try it without worrying about lock-in.

The full comparison is on T3 Code vs Claude Code CLI.

Running Claude and Codex side by side#

Nothing stops you authenticating both. Different agents have genuinely different strengths, and having both available in one interface — switching per thread, or even mid-thread — is one of the better arguments for T3 Code over any single-vendor GUI.

Troubleshooting#

• claude not found but works in your shell — PATH inheritance. Fix → (the mechanism is identical for any provider)
• Session won't start — update the CLI first. Version skew is the usual cause
• Auth expired mid-session — claude auth login again
• Rate limited — that's your Anthropic account, not T3 Code

FAQ#

Does T3 Code work with Claude Code?#

Yes. Install the Claude Code CLI with npm i -g @anthropic-ai/claude-code, authenticate with claude auth login, and T3 Code will drive it as a provider.

Can I use my Claude subscription with T3 Code?#

Yes. T3 Code uses whatever your Claude Code CLI is authenticated with, including a subscription. There is no separate T3 Code billing and no proxy between you and Anthropic.

Does T3 Code support Claude Opus 5?#

Yes. Claude Opus 5 model support was added in a July 2026 nightly build, alongside a restored model picker layout in the composer.

Can I use Claude Code and Codex at the same time in T3 Code?#

Yes. Authenticate both CLIs and switch between agents per thread, or even within a thread, without managing separate terminal sessions.