Launch HN: Relace (YC W23) – Models for fast and reliable codegen

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 ... Read full article.