openclaw/extensions/deepseek/stream.ts

import type { ProviderWrapStreamFnContext } from "openclaw/plugin-sdk/plugin-entry";
import { streamWithPayloadPatch } from "openclaw/plugin-sdk/provider-stream-shared";

type DeepSeekThinkingLevel = ProviderWrapStreamFnContext["thinkingLevel"];

function isDeepSeekV4ModelId(modelId: unknown): boolean {
  return modelId === "deepseek-v4-flash" || modelId === "deepseek-v4-pro";
}

function isDisabledThinkingLevel(thinkingLevel: DeepSeekThinkingLevel): boolean {
  const normalized = typeof thinkingLevel === "string" ? thinkingLevel.toLowerCase() : "";
  return normalized === "off" || normalized === "none";
}

function resolveDeepSeekReasoningEffort(thinkingLevel: DeepSeekThinkingLevel): "high" | "max" {
  return thinkingLevel === "xhigh" || thinkingLevel === "max" ? "max" : "high";
}

function stripDeepSeekReasoningContent(payload: Record<string, unknown>): void {
  if (!Array.isArray(payload.messages)) {
    return;
  }
  for (const message of payload.messages) {
    if (!message || typeof message !== "object") {
      continue;
    }
    delete (message as Record<string, unknown>).reasoning_content;
  }
}

function ensureDeepSeekToolCallReasoningContent(payload: Record<string, unknown>): void {
  if (!Array.isArray(payload.messages)) {
    return;
  }
  for (const message of payload.messages) {
    if (!message || typeof message !== "object") {
      continue;
    }
    const record = message as Record<string, unknown>;
    if (record.role !== "assistant" || !Array.isArray(record.tool_calls)) {
      continue;
    }
    if (!("reasoning_content" in record)) {
      record.reasoning_content = "";
    }
  }
}

export function createDeepSeekV4ThinkingWrapper(
  baseStreamFn: ProviderWrapStreamFnContext["streamFn"],
  thinkingLevel: DeepSeekThinkingLevel,
): ProviderWrapStreamFnContext["streamFn"] {
  if (!baseStreamFn) {
    return undefined;
  }
  const underlying = baseStreamFn;
  return (model, context, options) => {
    if (model.provider !== "deepseek" || !isDeepSeekV4ModelId(model.id)) {
      return underlying(model, context, options);
    }

    return streamWithPayloadPatch(underlying, model, context, options, (payload) => {
      if (isDisabledThinkingLevel(thinkingLevel)) {
        payload.thinking = { type: "disabled" };
        delete payload.reasoning_effort;
        delete payload.reasoning;
        stripDeepSeekReasoningContent(payload);
        return;
      }

      payload.thinking = { type: "enabled" };
      payload.reasoning_effort = resolveDeepSeekReasoningEffort(thinkingLevel);
      ensureDeepSeekToolCallReasoningContent(payload);
    });
  };
}