Prompt Engineering Context Code

Split Large Codebase Context — File Boundaries, Atomic Fences

Code split mid-function is unreviewable. Codebase mode splits at file boundaries, keeps fenced blocks atomic, and lists the files in every chunk.

Overview

Splitting source code is where blind chunking fails hardest: a function severed across messages, a fence broken so the syntax highlighting collapses, files blended into anonymous soup. Codebase mode treats code as code: file markers become preferred boundaries, fenced blocks are atomic units the packer never breaks when avoidable, every chunk carries its own file list, and the model is told not to review anything until the final chunk declares the codebase complete. This setup loads a multi-file billing module with the review task delivered exactly when it should be — after everything has arrived.

How to use this resource

  1. Keep the file markers

    "File: src/…" lines become split boundaries and per-chunk inventories — structure in, structure out.

  2. Trust the atomic fences

    Fenced blocks travel whole; a forced continuation is explicitly marked, never silent.

  3. Review only when complete

    The final chunk declares the codebase complete and triggers the task — no premature reviews of half a module.

Why This Works

  • File-aligned chunks keep code referenceable by name and location
  • Atomic fences preserve the syntactic integrity reviews depend on
  • The completion gate stops reviews of half-delivered code

Best for

  • Code reviews that span more files than one message holds
  • Sharing project source with file structure intact
  • Developers whose pasted code keeps getting answered early

Not for

  • Writing the review contract itself — that's the Code Review Prompt Generator
  • Estimating how many files fit per chunk — that's the Context Window Estimator's codebase budgeting

Use cases

  • Feeding a multi-file module into one conversation
  • Keeping functions and fences intact across chunks
  • Holding the review until the codebase is complete

FAQ

How do I send a multi-file codebase to AI without breaking functions across messages

Codebase Mode prefers file boundaries as split points and keeps fenced blocks atomic, so a function isn't severed mid-message. Long Prompt Splitter produces the numbered chunks; you send each as one message and wait for the model's "Received chunk i of 3" acknowledgement before the next, keeping the delivery ordered and referenceable.

How do I stop the model reviewing my code before all the files arrive

Each chunk header says do not review, fix, or execute anything yet, and the TASK to review the billing module runs only after the ALL CHUNKS DELIVERED gate declares the codebase complete. That completion gate is what prevents a premature review of half a module, so the review runs against the whole thing.

How will I know which files landed in each chunk

Every chunk carries its own "Files in this chunk" list, for example src/billing/proration.js and src/billing/invoice.js, alongside "### File:" markers that double as split boundaries. That way you can name the file and chunk for any claim, which the final gate explicitly asks you to preserve when referencing code.

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