Scale Coding Projects with Claude Opus 5’s 128k Output Window
Generate entire repos in one go using 128k output tokens.
Utilize the high output token limit of Claude Opus 5 to generate massive, multi-file codebases or long-form reports without the need for manual chunking.
The Scenario
You are starting a complex software engineering project from scratch and need the AI to architect and write a significant portion of the codebase in one session.
Before & after
Manually breaking a large coding project into 10 smaller modules and prompting back and forth for each function. Total time: 2-3 hours.
Use Opus 5 with the 'max' effort setting to let the model 'think' through the logic and generate up to 128k output tokens in one go. Total time: 5-10 minutes.
The Prompt
I need to build a repository-scale software engine for [SPECIFIC_PROJECT_PURPOSE]. Using your maximum 'thinking' effort and taking advantage of your 128k output limit, please write the complete file structure and the full code for all core modules, explaining your architectural decisions in the process. [RESOURCES/CONTEXT]
Claude Opus 5 features 'thinking' enabled by default and a massive 128k output token limit, making it ideal for generating entire codebases or long documentation without hitting length limits.
Source
Claude Platform release notes - Claude Platform Docs"Claude Opus 5 supports a 1M token context window... 128k max output tokens, and thinking enabled by default."