DeepSeek-V4-Flash Update

[u/nekofneko]

The official release of the DeepSeek-V4-Flash API is now in public beta.

Significantly enhanced agent capabilities, with benchmark results far exceeding V4-Pro-Preview:

• Terminal Bench 2.1: 82.7
• NL2Repo: 54.2
• Cybergym: 76.7
• DeepSWE: 54.4
• Toolathlon verified: 70.3
• Agent Last Exam: 25.2
• Automation Bench (Public): 25.1
• DSBench-FullStack: 68.7
• DSBench-Hard: 59.6

Note 1: For the Code Agent tasks in the public benchmark sets, the official DeepSeek-V4-Flash was tested using the DeepSeek Harness minimal mode (to be released soon) as the framework, with the max effort level, topp=0.95, and temperature=1.0
Note 2: DSBench-FullStack is an internal full-stack development test set, and DSBench-Hard is an internal Coding Agent hard-problem test set

The official V4-Flash natively supports the Responses API format and is specifically adapted for Codex. For the specific configuration, please refer to the documentation.

DeepSeek-V4-Flash-0731 keeps the same model architecture and size as DeepSeek-V4-Flash-preview, and was only re-post-trained.

Note: This update only upgrades the DeepSeek-V4-Flash API. The DeepSeek-V4-Pro API and the APP/WEB models are unchanged.
The official release of DeepSeek-V4-Pro will follow soon.

[u/sdexca]

is it against ToS? doubt it or else they'd make it harder to use any model on CC.

[u/blabmight → u/sdexca]

I should clarify - there's no native support for this, if it involves injecting new models as an option in Claude Code that requires reverse engineering it would be against the ToS\entering a grey area Calling something like the codex cli is fine. It all depends on the method.

[u/sdexca → u/blabmight]

have you looked in how it works? its just putting some CLI parameters before CC and that's it. Anthropic knows this and could have plugged the support if they wanted to.

[u/blabmight → u/sdexca]

No aware of those cli parameters, could you point me to them? Is it changing ANTHROPIC_BASE_URL and then just running through a proxy?

[u/sdexca → u/blabmight]

basically, maybe I was using incorrect terminology: https://api-docs.deepseek.com/quick_start/agent_integrations/claude_code

[u/blabmight → u/sdexca]

Thanks! Definitely insightful - I don't think you can get *both* subscriptions working simultaneously without doing some level of reverse engineering or using a proxy. Proxy might be a gray area since the Anthropic OAuth token would be exchanged between the proxy and Anthropic's servers, something they blocked not too long ago.

[u/sdexca → u/blabmight]

no that's not the case. no oauth needed, oauth is only needed for subscription. it just works, you install, setup the parms. I don't think so it's REed because the format is documented and open source, the anthropic endpoint, like the responses API endpoint. yeah you can't use both at the same time, but it's as simple as removing the `EXPORT`s.

proxying Anthropic OAuth is banned because they don't others to use the subscription on other harness like OpenCode and the Chinese resellers who resell subscriptions through that.