DeepSeek put official DeepSeek-V4-Flash API into public beta July 31, 2026 (Flash-0731). Same architecture as preview; re-post-trained. Native Responses API; Codex integration. HF: deepseek-ai/DeepSeek-V4-Flash-0731 MIT. Vendor Terminal Bench 2.1 82.7 cited. Pricing ~0.28 per M tokens. Pro API unchanged. Harness for independent verification promised but unreleased.