Bifrost MCP server

<!-- mcp-name: io.github.FixemBCN/mcp-bifrost -->

MCP-Bifrost

Rewrite 200 methods with a cheap model, without a single line of the result passing through the expensive one's context — and without writing anything to disk that does not compile.

An MCP server that takes code work already analysed and split up by an orchestrating model, extracts the exact target block with the language's own parser, delegates the rewriting to a cheaper worker model, validates the result, applies it atomically, and records the whole thing outside the orchestrator's context.

The head decides. The muscle types. Bifrost is the nerve between them — and the part that guarantees nothing reaches disk broken.

In the examples below the head is Claude and the muscle is DeepSeek, which is simply the model that was to hand. Neither is a requirement. See The worker for why a 7B model on your own machine may be the more interesting choice.

Why

A large codebase edited by an LLM has one real bottleneck, and it is not intelligence: it is context. Reading a 4,600-line file to change thirty lines of it burns the orchestrator's window on text it will never use again.

Bifrost's premise is that the mechanical half of coding — writing the replacement text — does not need the expensive model, and does not need to pass through its context at all.

The honest version (see RF-4): for a single small edit the saving is real but modest, because the orchestrator usually had to read the code anyway to say what it wanted. The order-of-magnitude win is in volume — transformations across many symbols where the instruction can be written without reading anything.

That is the use case this is built for. Not "fix this bug."

And the number the log reports is a counterfactual. The test suites in this repository were written through Bifrost itself: 97,909 bytes applied from 1,608 bytes of instruction, which the formula scores at 61×. The realised saving was zero, because the blocks were composed by the orchestrator rather than by a worker, and every one of those bytes was paid before Bifrost saw them. The log records what crossed the boundary, not where it was written. The worked example is in §11, kept unflattering on purpose.

When not to use it

Shortened. The full README is on GitHub.