14 ms·

Can someone explain how this actually can go faster than other harnesses? 1. Model routing. Do you regret giving a task to Fable when it could have literally b

Can someone explain how this actually can go faster than other harnesses? 1. Model routing. Do you regret giving a task to Fable when it could have literally been done by Sonnet? This is the one thing that I can understand. 2. Targeted code + context search. We think embedding the whole repo is dumb. We also think sticking the whole context (or compressed context) in chat is dumb. So we do faster and better greps over both. Is this just a different system prompt? Why would other harnesses not be able to do it this way given instructions to do so? 3. Aggressive context hygiene. Tool output is bounded, stale screenshots disappear, we don’t re-read files…the garbage never floods the model. Existing harnesses already don't re-read files that have not changed. And content that is already in the context window is cached tokens and doesn't add significant latency, what am I missing? Removing context from history invalidates KV cache. 4. Efficient turns. Batch independent investigation, make one surgical edit, then perform one focused verification. Internal measurement showed 16% fewer round trips and 27% lower cost. Isn't this just a specific sub-agent strategy, also addressable with prompting? I'm genuinely confused about what is mechanically different in this harness that could not be accomplished with a prompt/skill in another harness.

andai 1mo ago
(Not the author but) To your last question, I was able to replicate some of the benefits of my custom harness in Claude by just adding a custom MCP, startup hooks etc. The issue I ran into is that I was fighting Claude's system prompt, which told it to do things which negated most of the benefits of my setup... For context my startup hook was "grep def", lol. (Now working in js I have grep function, grep class, interface etc.). Gives it a little outline for context, saves time poking around blindly. My repos are small though, this is still a big blob if you have very large repos.

andai 1mo ago

(Not the author but) To your last question, I was able to replicate some of the benefits of my custom harness in Claude by just adding a custom MCP, startup hooks etc. The issue I ran into is that I was fighting Claude's system prompt, which told it to do things which negated most of the benefits of my setup... For context my startup hook was "grep def", lol. (Now working in js I have grep function, grep class, interface etc.). Gives it a little outline for context, saves time poking around blindly. My repos are small though, this is still a big blob if you have very large repos.