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# 🤖 AI Agents Weekly: DeepSeek Harness, DeepSeek-V4-Pro, Grok Bot, GLM-5.3, Gemini 3.7 Flash, Muse Glimmer, Harness Evolution Papers, and More
### DeepSeek Harness, DeepSeek-V4-Pro, Grok Bot, GLM-5.3, Gemini 3.7 Flash, Muse Glimmer, Harness Evolution Papers, and More
Aug 15, 2026
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In today’s issue:
  * DeepSeek open-sources its agent harness
  * DeepSeek-V4-Pro ships agent upgrades
  * xAI launches Grok Bot teammates
  * Z.ai drops GLM-5.3 for coding
  * Gemini 3.7 Flash halves coding cost
  * Meta open-sources Muse Glimmer
  * Grok 4.6 hits frontier at half price
  * Zed launches Delta for agent teams
  * Evo-Bench measures harness evolution
  * Study finds 91.8% of skills defective


And all the top AI dev news, papers, and tools.
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## Top Stories
### DeepSeek Open-Sources Its Agent Harness
[![DeepSeek Harness plugin list](https://substackcdn.com/image/fetch/$s_!YLVq!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F87990d1b-8dde-4823-aa55-2e242cafbf66_1520x950.png)](https://substackcdn.com/image/fetch/$s_!YLVq!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F87990d1b-8dde-4823-aa55-2e242cafbf66_1520x950.png)
DeepSeek released DeepSeek Harness v0.1 as a developer preview, open-sourcing the codebase under MIT and opening it to anyone building agent harnesses.
  * **Everything is a plugin:** The harness is built on the Cordis meta-framework, a kernel that mounts, unmounts, and resolves dependencies for models, tools, skills, sessions, sandboxes, storage, loops, scheduling, and UI as independent plugins.
  * **Append-only session log:** Everything the model sees is recorded, so sessions can be resumed, forked, searched, and replayed rather than reconstructed from chat history.
  * **Four runtime modes:** Standard ships the full toolset, Code orchestrates operations through TypeScript, Minimal strips down for benchmark runs, and Creator is for building custom presets.
  * **Install path:** Runs via `npx @deepseek-ai/dsh web` or from source, and the repo has already cleared 93,000 stars.


**[Blog](https://deepseek.com/harness/en/)** | **[GitHub](https://github.com/deepseek-ai/deepseek-harness)**
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### DeepSeek Launches V4-Pro
[![DeepSeek-V4-Pro benchmarks](https://substackcdn.com/image/fetch/$s_!sguK!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fba1e0d1b-414f-4bd9-9c92-59b61fa02215_2047x906.jpeg)](https://substackcdn.com/image/fetch/$s_!sguK!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fba1e0d1b-414f-4bd9-9c92-59b61fa02215_2047x906.jpeg)
DeepSeek shipped V4-Pro-0813, a general availability release centered almost entirely on agent workloads.
  * **Agentic benchmarks:** 87.9 on Terminal Bench 2.1, 62.7 on DeepSWE, 74.1 on Toolathlon-Verified, 83.3 on CyberGym, and 31.8 on public AutomationBench, tested through DeepSeek Harness in minimal mode.
  * **Flexible reasoning effort:** Low, high, and max tiers across V4-Pro and V4-Flash let you dial spend per task instead of paying reasoning cost on trivial calls.
  * **Native Responses API:** Ships OpenAI Responses API support with one-click Codex setup, and model names stay unchanged so existing integrations keep working.
  * **Peak and off-peak pricing:** New API rates take effect August 16, with off-peak rates 50% below peak for schedulable batch and agent workloads.


**[Blog](https://api-docs.deepseek.com/news/news260813/)**
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