CodeBot for Delphi: A Deep Dive into the New AI Assistant

Delphi developers have been the neglected stepchildren of the AI coding boom, so an assistant trained specifically for Object Pascal and the RAD Studio IDE is a bigger deal than it sounds. CodeBot isn't just a generic LLM wrapper — it hooks into the Delphi language server and understands unit scoping, generics, and the VCL/RTL quirks that make generic copilots second-guess themselves. After a week of real project work, here are the full details worth knowing.

What Actually Runs Under the Hood

CodeBot is a local/cloud hybrid agent. The IDE extension handles context extraction — open units, cursor position, compile errors, and the current project's unit dependency graph. That context gets compressed into a prompt and sent to a fine-tuned model that has seen a large chunk of Delphi open-source code and Stack Overflow answers. The result comes back as either inline completions or full refactor proposals, not just "explain this code" chat.

First Run, Step-by-Step

1. Install the IDE plugin from the RAD Studio repository manager.
2. Get an API key from the CodeBot dashboard (there's a free tier with 500 requests/day).
3. Open the CodeBot panel, point it at your .dproj file, and let it index for a minute or two.
4. Hit Alt+C to generate at cursor, or Alt+R for refactor suggestions on a selection.

The indexing stage is the important part. CodeBot builds a local semantic map of your units, so when you ask it to "add error handling to this data module," it already knows which exception classes your project standardizes on.

A Real-World Prompt Workflow

I spent an afternoon migrating a legacy forms app to a cleaner MVVM structure. The practical tutorial that worked best was giving CodeBot a single unit at a time and asking for concrete change sets, like this:

Refactor TCustomerForm in CustomerForm.pas to separate the business logic into a TCustomerViewModel class. Keep the VCL form as a thin view, preserve all existing event handlers' behavior, and use the currently injected TCustomerService from unit CustomerService.pas. Respond with the full new unit code plus a diff outline.

The output wasn't perfect — the generated view-model had a duplicate property definition and one over-eager Try block. But the diff outline made it easy to spot the mistakes. CodeBot also generated the unit tests in two seconds flat, something I usually skip because it takes too long by hand.

Honest Impressions After Real Use

• Completion quality: noticeably better than generic copilots on VCL and FMX code. It knows TStringList ownership semantics and won't suggest leaks.
• Refactoring: the strongest feature. It respects the existing code style and unit boundaries.
• Test generation: baseline DUnitX tests are solid; edge-case coverage is still on you.
• Slowpoints: large multi-unit refactors can take up to a minute, and it occasionally pulls the wrong unit context if a project has duplicate filenames.
• Deployment: if you're behind a corporate firewall, you'll need the on-prem option — setup is straightforward but requires a separate server.

The real value isn't autocomplete. It's the ability to say "turn this 400-line unit into a maintainable pattern" and get a starting point that's 80% right. For a niche ecosystem like Delphi, that's a rare and welcome thing.

If you've been wondering whether AI can handle Object Pascal at all, CodeBot is the first answer that feels like it actually respects the language's constraints.