DeepSeek V4-Flash official API: public beta with upgraded agent capabilities, Responses API and Codex support
DeepSeek's official V4-Flash is now a public beta API with massively upgraded agent capabilities - benchmark scores said to far surpass the V4-Pro-Preview - native Responses API format support and full adaptation for Codex. The official V4-Pro release is coming soon.
Why it matters
The model that ranked #2 by OpenRouter call volume in July now gets first-party agent tooling: Responses API compatibility and Codex adaptation turn an already-popular open-weights coder into a drop-in agentic-coding backend at DeepSeek's aggressive pricing.
What you could build with it
A devtools startup could ship an agentic coding assistant on V4-Flash's Responses API backend: near-frontier coding at a fraction of GPT/Claude cost, with Codex compatibility handling the tool-use plumbing.
Does it hold up?
Early but encouraging - V4 Flash was the second most-called model on OpenRouter in July, so developers are already voting with traffic; the official API upgrade is days old, so independent reports on the new agent capabilities are still arriving.
Built with DeepSeek V4-Flash official API
- DeepSeek V4.1 Flash / V4 Pro / R1 / V3.2 compared (Sept 2026)article · Independent comparison covering V4.1 Flash (552B MoE, MIT-licensed weights, 1M context) against V4 Pro and earlier families.
- Engineer testing notes on the DeepSeek V4 previewarticle · AI engineer Daniel Dewhurst's early testing notes: calls the V4 preview significant but cautions against taking benchmark headlines at face value before independent evaluation.
Learn more
First spotted on article: source.
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