# Echo: Cutting Costs to One-Third with Open-Weight Models

Fable-level results at one-third the cost.

- **Source:** [Hacker News](https://news.ycombinator.com)
- **Published:** 2026-07-23
- **Topic:** [Data & AI](https://brifing.si/c/data-ai)
- **Original article:** <https://news.ycombinator.com/item?id=49026810>
- **On Brifing:** https://brifing.si/s/b4c0d7ad-9633-4c89-800d-3fc819d80a18

## What is Echo?

Echo is an experiment that uses a pool of open-weight models to create a single AI system. It selects the most suitable models for each task and combines their outputs.

## Initial Experiment

The project started with models like GLM-5.2 and Kimi K2.7. Each model was subjected to the same evaluations, and the best combinations were analyzed.

## Hypothesis and Reality

The hypothesis was that knowing the best models for each problem in advance would improve performance. Echo aims to achieve this advantage without prior knowledge.

## Computation Allocation

Echo decides how much computational power to allocate, which models to use, and how to combine outputs for each request.

## Model Complementarity

A model that is generally weaker can be extremely useful in specific problems or combinations. Echo leverages this complementarity.

## Results and Cost

Echo achieves results similar to Fable at one-third the cost. However, it can make wrong allocation or combination decisions in some cases.

## Sources covering this story

- https://news.ycombinator.com/item?id=49026810 — 

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_Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._
