DeepSeek Clarifies Claude Model Mapping and Flash Fallback

Migrated with permission from DeepSeek V4 Pro, a related editorial property operated by our team.

Checked on June 25, 2026: DeepSeek's official Anthropic API page says claude-opus* maps to V4 Pro, claude-haiku* and claude-sonnet* map to V4 Flash, unsupported model names automatically fall back to Flash, and the mapping can help bypass Claude Desktop developer-mode model-name restrictions.

What we verified on June 25, 2026

DeepSeek's official Anthropic API guide publishes an explicit Claude-name mapping rule: claude-opus* routes to deepseek-v4-pro, while claude-haiku* and claude-sonnet* route to deepseek-v4-flash.

The same official page warns that unsupported model names are not rejected hard by default. DeepSeek says the Anthropic API backend will automatically map an unsupported model name to deepseek-v4-flash.

DeepSeek also frames this mapping as useful inside the new Claude Desktop app's developer mode: the docs say that by changing only the base URL and API key, users can bypass the app's model-name restrictions and still connect to DeepSeek models.

The official endpoint contract remains simple: https://api.deepseek.com/anthropic with Anthropic-style clients, rather than inventing a separate DeepSeek-only SDK surface for this workflow.