copilot (and others) try to be too smart and do context reduction (to save their own wallets). I want ENTIRETY of the files I attached to context, not RAG-ed version of it.

This problem is real.

Claude Projects, chatgpt projects, Sourcegraph Cody context building, MCP file systems, all of these are black boxes of what I can only describe as lossy compression of context.

Each is incentivized to deliver ~”pretty good” results at the highest token compression possible.

The best way around this I’ve found is to just own the web clients by including structured, concatenation related files directly in chat contexts.

Self plug but super relevant: I built FileKitty specifically to aid this, which made HN front page and I’ve continued to improve:

https://news.ycombinator.com/item?id=40226976

If you can prepare your file system context yourself using any workflow quickly, and pair it with appropriate additional context such as run output, problem description etc, you can get excellent results and you can pound away at OpenAI or Anthropic subscription refining the prompt or updating the file context.

I have been finding myself spending more time putting together prompt complexity for big difficult problems, they would not make sense to solve in the IDE.

I believe this is the root of the problem for all agentic coding solutions. They are gimping the full context through fancy function calling and tool use to reduce the full context that is being sent through the API. Problem with this is you can never know what context is actually needed for the problem to be solved in the best way. The funny thing is, this type of behavior actually leads many people to believe these models are LESS capable then they actually are, because people don't realize how restricted these models are behind the scenes by the developers. Good news is, we are entering the era of large context windows and we will all see a huge performance increase in coding as a results of these advancement.

Regarding context reduction. This got me wondering. If I use my own API key, there is no way for the IDE or coplilot provider to benefit other than monthly sub. But if I am using their provided model with tokens from the monthly subscription, they are incentivized to charge me based on tokens I submit to them, but then optimize that and pass on a smaller request to the LLM and get more margin. Is that what you are referring to?

FWIW, Edit mode gives the impression of doing this, vs. originally only passing the context visible from the open window.

You can choose files to include and they don't appear to be truncated in any way. Though to be fair, I haven't checked the network traffic, but it appears to operate in this fashion from day to day use.

Thanks, most people don't understand this fine difference. Copilot does RAG (as all other subscription-based agents like Cursor) to save $$$, and results with RAG are significantly worse than having the complete context window for complex tasks. That's also the reason why Chatgpt or Claude basically lie to the users when they market their file upload functions by not telling the whole story.

Cline doesn’t do this - this is what makes it suitable for working with Gemini and its large context.

Is that why it’s so bad? I’ve been blown away by how bad it is. Never had a single successful edit.

The code completion is chefs kiss though.