DeepSeek Tool Calls Docs Define Strict Beta Schema Rules

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

Checked on June 29, 2026: DeepSeek's official Tool Calls guide documents OpenAI-compatible function calling, a Beta-only strict mode for exact schema matching, concrete supported and unsupported JSON Schema rules, and a required tool role replay pattern after execution.

What we verified on June 29, 2026

DeepSeek's official Tool Calls guide now documents a full OpenAI-compatible function-calling contract for chat completions, including tools definitions and tool_calls output in assistant responses.

The same page adds a stricter beta path: you can set strict: true on a function schema for more precise argument matching, but the docs mark that mode as Beta and require the Beta base URL.

DeepSeek publishes a concrete schema support boundary for strict mode: supported types are string, number, integer, boolean, object, array, enum, and anyOf.

The same strict-mode note also lists unsupported schema features such as minLength, maxLength, pattern, format, minimum, maximum, multipleOf, patternProperties, and array bounds like minItems and maxItems.

The replay contract after execution is concrete: callers should append the assistant message that contains the tool call, then append a tool role message with the returned result before asking the model for the next turn.