Hey HN community! We're Preston and Eitan, and we're building Relace (https://relace.ai). We're trying to make building code agents easy and cheap.

Here’s an example of our apply model vs. whole file edits: https://youtu.be/J0-oYyozUZw

Building reliable code agents is hard. Beyond simple prototypes, any app with code generation in production quickly runs into two problems -- how do you reliably apply diffs, and how do you manage codebase context?

We're focused on solving these two problems at order-of-magnitude lower price and latency.

Our first model that we released, in February, is the Fast Apply model -- it merges code snippets with files at 4300 tok/s. It is more reliable (in terms of merge errors) than Sonnet, Qwen, Llama, or any other model at this task. Each file takes ~900ms and gives an instantaneous user experience, as well as saving ~40% on Claude 4 output tokens.

Our second model focuses on retrieval. For both vibe-coded and enterprise codebases, retrieving only the files relevant to a user request saves both on SoTA input token cost and reduces the number of times code agents need to view files. Our reranker (evals below) can scan a million-line codebase in ~1-2s, and our embedding model outperforms any other embedding model for retrieval as evaluated on a corpus of Typescript/React repositories.

There are many different ways to build coding agents, but being able to edit code reliably and retrieve the most relevant parts of the codebase is going to be a foundational issue. We're excited to be building ways to make it more accessible to millions of users who don't want to spend $$$ on Claude.

These models are used in production, millions of times per week. If you've used Lovable, Create.xyz, Magic Patterns, Codebuff, Tempo Labs then you've used us!

Here's a link to try it out: https://app.relace.ai, and here are our docs: https://docs.relace.ai.

We've opened up free access for prototyping on our website to everyone, and the limits should be enough for personal coding use and building small projects (correct us if it’s not). We integrate directly with Open-Source IDE's like Continue.dev. Please try us out, we'd love to hear your feedback!