best practice

Migration Guide: Switch to DeepSeek-V4 Before the July 2026 Deprecation

Q: What prompt should I use?

Update your API configuration: Change 'model' parameter from 'deepseek-chat' to 'deepseek-v4-flash' Change 'model' parameter from 'deepseek-reasoner' to 'deepseek-v4-pro' Base URL remains: https://api.deepseek.com/v1 (or your custom enterprise URL)

Published 06:03 MYT · Jun 22

Update your API model parameters to V4 to avoid service disruption.

Switch your API model IDs from legacy names to 'deepseek-v4-pro' or 'deepseek-v4-flash' before July 2026 to ensure stability.

DeepSeek

The Scenario

You are a developer or technical lead maintaining an application that uses DeepSeek's API and you want to ensure your integration doesn't break when legacy models are retired.

Before & after

The old way

Developers manually monitored model deprecations and switched between older 'chat' and 'reasoner' endpoints, often dealing with character mixing issues. Cost: 30–60 minutes of maintenance per update.

With AI

Using DeepSeek-V4-Flash via the standard API takes seconds to configure, providing frontier performance and better multi-language support instantly. Cost: <1 minute for setup.

The Prompt

Update your API configuration:
Change 'model' parameter from 'deepseek-chat' to 'deepseek-v4-flash'
Change 'model' parameter from 'deepseek-reasoner' to 'deepseek-v4-pro'
Base URL remains: https://api.deepseek.com/v1 (or your custom enterprise URL)

DeepSeek recently consolidated their models. The names 'deepseek-chat' and 'deepseek-reasoner' are legacy and will be discontinued on 2026-07-24. Switch your API calls to 'deepseek-v4-pro' for maximum power or 'deepseek-v4-flash' for speed and efficiency.

Source

Change Log | DeepSeek API Docs

"The two legacy API model names, deepseek-chat and deepseek-reasoner, will be discontinued in three months (2026-07-24)."