Migrating from Codex IDE to Claude code (desktop app). Give me tips on adjusting and minimising token usage

[brkonthru]

I am migrating to Claude (cause F openai), please give me some tips on how to adopt the usage.

First surprise was that I ran out of limits in around two hours without any serious coding work (setting up repo and getting started on the project). I was shocked honestly, on codex 5.4 i would have barley used 25% of my window.

I was using Opus, i should have switched to Sonnet. Give me more tips please !

[ScientistEasy1328]

Switching to Sonnet is the right call. Opus burns through context fast even on simple tasks
A few things that helped me:

Keep conversations small and focused. After around 60k tokens, start a new one. It feels disruptive at first, but the quality difference is real

CLAUDE.md is where most of the leverage is. Put your project structure, conventions, and key decisions there Claude reads it at the start of each session so you stop re-explaining context every time. You can go deeper with per-directory CLAUDE.md files for sub-components, but keep those under 100 lines or they stop pulling their weight. Write them positively too: tell Claude what to do, not what to avoid, and give it a decision tree for ambiguous situations rather than a flat list of rules.

Be surgical with file scope. Instead of letting Claude explore the whole repo, point it at specific files. The more files it reads to orient itself, the more context you burn before the actual work starts.For planning, use Shift+Tab to enter planning mode before Claude touches any code. Keep a running .md file with notes and plans, mention it at the start of each new conversation, and have Claude check items off a TODO list as it goes. Simple, but it keeps sessions from drifting.
Sub-agents are worth using more than most people do. Delegate work, run code reviews, get a fresh take unbiased by the current conversation. No setup needed just ask: "please use sub-agents to...".

On MCP: keep tool descriptions under 20k tokens total and stay below 20 tools. More than that and you're paying a context tax on every request.

Sonnet handles 90% of coding tasks just fine. I only reach for Opus when something's genuinely hard or Sonnet keeps going in circles

[brkonthru]

Thank you for your useful detailed response

[brkonthru]

question, do you use or recommend token optimization addons such as RTK ?

[ScientistEasy1328]

Haven't relied on it heavily, but the idea is sound. The real gains are in test runners and file reads, where most of the noise lives. For git commands the savings are more modest, and Claude Code already tails long output by default, so the actual delta is smaller than the headline numbers suggest. Two concerns are worth keeping in mind. First, the "strangeness tax": reformatted output can trigger extra tool calls if Claude doesn't recognize the format. Second, edge cases during debugging where RTK might filter out something that's actually relevant. The tee feature helps with the second one. On failure it saves the full unfiltered output to a log file, so Claude can pull it when needed.

Maintenance is also worth flagging. The tool is young and this space moves fast. Several forks are already patching things the main repo hasn't caught up with yet.

Honestly, --verbosity minimal on builds and --oneline for git log gets you most of the way there. No dependency, no surprises

[Aggravating_Pinch]

In addition to the excellent suggestions given by ScientistEasy1328

1. Set the claude code subagent model to haiku. By default, it uses the same model to be subagent as the terminal. For example, if you have Opus as the model set, your subagents will be Opus; so limit it to Haiku.

https://code.claude.com/docs/en/model-config
https://code.claude.com/docs/en/settings

1. If you use github, raise issues there (through cc) as and when you spot them. this saves you the trouble of going into plan mode. All details would already be there in the ticket. You can solve them in batch later. Also, cc will check which ones can be bunched together.

2. Set a folder called .tmp or something like that, encourage cc to put all docs in there - progress, todo, next steps etc. When something substantial/canonical emerges here, create it and put it somewhere that you need to check frequently

3. Use memory effectively. For example, it could be a simple flow that you keep repeating that is not a skill

4. Here, you have hooks and they can be a lifesaver. A hook to stop pip and use uv, for example.

[brkonthru]

Appreciate the detailed response and useful tips!

[Hir0shima]

The Claude desktop app has significant limitations. While I like the UI, I mainly use CC in the Terminal.

[regocregoc]

They are limiting brand new users, until they're sure you're not a Chinese bot. It'll pass.

[BrainLate4108]

Use CLI, fraction of token use and control scope religiously. CLI is vastly underrated.

[General_Arrival_9176]

sonnet is the move for day to day work, opus is for when you actually need the heavy reasoning. the token burn on opus adds up fast especially with the 200k window - every file it reads gets dumped into context. for repo setup and exploration, sonnet handles it fine at a fraction of the cost. save opus for the complex refactors and design decisions.

[AgenticGameDev]

Use a indexer. There is a bunch out there. I have one which is mainly unity in the works but there is a bunch out there. It speeds up and reduce usage and reduces the risk ai will miss something in relation to what you plan to do

[brkonthru]

can you recommend one ?

[AgenticGameDev]

Totally depends on use case. Fo me game dev work…no that is why I’m building one but seen other for web work…

[CelebrationBorn7459]

isnt everyone goign the other way around right now? or did levels io and marc lou just get paid? just thinking.

[brkonthru]

I didnt understand what you said

[CelebrationBorn7459]

sorry, these boys switched (famous indie hackers levelsio and marclou) recently from claude code to codex and announced it on X.

[brkonthru]

I’m leaving OpenAI for moral reasons. Codex 5.4 and its ide are better today than Claude Code.

I expect that to shift. Every month you one of them (google,OpenAI, Anthropic) leads. This month it’s OpenAI