Meta 发布编码智能体 Muse Code 与 Muse Spark 1.2
Original title: Introducing Muse Code and Muse Spark 1.2
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Meta 发布编码智能体 Muse Code 和面向编码的模型更新 Muse Spark 1.2,后者在代码生成、复杂调试、代码库理解和端到端开发流程上做了改进,并针对长周期编码任务(整仓库生成、大型端到端项目、auto-research)加大训练算力。
5th August 2026 - Link Blog
Introducing Muse Code and Muse Spark 1.2 (via) Yet more evidence that the most important characteristic of any model these days is long-sequence agentic tool calling. Meta shipped their own coding agent as part of getting that to work!
Muse Spark 1.2 is a coding-focused update to Muse Spark 1.1, with improvements in code generation, complex debugging, codebase understanding, and end-to-end developer workflows. In Muse Spark 1.2, we significantly scaled up training compute on coding tasks while expanding training environment diversity. The model also maintains its strength in other key areas like general agents. [...]
We co-trained Muse Spark 1.2 with Muse Code to ensure the model exhibits its best performance and coding usability when paired together. The training included rejection sampled harness trajectories and recipe optimizations for goals, compaction, and subagents, alongside the integration of the Muse Code toolset to maximize harness compatibility. [...]
Muse Spark 1.2 was extensively trained on long-horizon coding tasks, including whole-repository generation, large end-to-end projects, and auto-research.
Here's a pelican riding a bicycle SVG produced by Muse Spark 1.2:

You can see the Spark 1.1 pelican from 9th July here. I think the 1.2 pelican is a small but material improvement.
An interesting twist on pricing is that the model is offered as two different model IDs. muse-spark-1.2 is priced at $1.25/million input and $4.25/million output - close to Gemini 3.6 Flash ($1.50/$7.50) - but if you agree to let Meta use your data "to improve our products" you can use muse-spark-1.2-contributor which is $0.10/$0.20 - a huge discount, closer to GPT-5.6 Luna ($0.20/$1.20) and Gemini 3.1 Flash-Lite ($0.25/$1.50).
I added those new prices to llm-prices.com.
Source: Simon Willison · Coding Agents · simonwillison.net