prepareRequest + buildRequest：从日志折叠请求

529  private async prepareRequest(turn: number, step: number, signal: AbortSignal): Promise<{ config; preparedCall? }> {   // 拆分 1解析配置 + 绑定 adapter
538    const persistedHeader = session.requestHeader()
539    const persistedConfig = persistedHeader?.config
541    const persistedReasoningEffort = persistedConfig?.provider === route.provider
543      && persistedHeader?.adapterDefaults?.reasoningEffort !== true
546    const reasoningEffort = this.options.reasoningEffort ?? persistedReasoningEffort
547    const maxTokens = this.options.maxTokens
548    const seedConfig = deepFreeze(structuredClone(
558    const proposedConfig = await this.dispatch.waterfall(
559      'agent/request', { turn, step, signal },
562    signal.throwIfAborted()
563    if (!proposedConfig.provider || !proposedConfig.model) {
564      throw new Error(`agent "${this.id}" has no provider/model: ...`)
565    }
566    let config: LlmCallConfig
567    let preparedCall: PreparedLlmCall | undefined
568    try {
569      preparedCall = await this.loopCtx.llm.prepareCall(proposedConfig, signal)
570      config = preparedCall.config
571    } catch (error: unknown) {
573      if (!(error instanceof LlmError) || error.code !== 'NO_ADAPTER') throw error
574      config = proposedConfig
575    }
576    signal.throwIfAborted()
577    return { config, ...preparedCall === undefined ? {} : { preparedCall } }   // 交给调用方step 用它投影 system
578  }
581  private buildRequest(config: LlmCallConfig, preparedCall: PreparedLlmCall | undefined,
585    startsRequestSeries: boolean, signal: AbortSignal): GenerateOptions {   // 拆分 2
588    const { session } = this
589    const surfaceGeneration = session.surface.contentGeneration   // 0.1.6：contentGeneration含插件改写
590    const header = canonicalHeader({
591      config,
592      ...preparedCall === undefined ? {} : { adapterDefaults: preparedCall.adapterDefaults },
593      ...tools.length > 0 ? { tools } : {},     // 注意：没有 system 字段
594    })
595    const baseline = this.session.requestHeader()
596    const startsSeries = startsRequestSeries
597      || this.requestSurfaceGeneration !== surfaceGeneration
598    if (!this.requestHeaderLogged) {
599      this.session.append('request/header', { header, reason: baseline === undefined ? 'initial' : 'resume' })
600      this.requestHeaderLogged = true
601    } else if (baseline === undefined || !headerEquals(baseline, header)) {
612    const contextWindow = preparedCall?.context?.contextWindow
613    const systemPromptUpdate = preparedCall?.systemPromptUpdate
614    const requestContext: RequestContext = {
615      provider: config.provider,
616      model: config.model,
617      ...contextWindow === undefined ? {} : { contextWindow },
618      ...systemPromptUpdate === undefined ? {} : { systemPromptUpdate },
619    }
620    const previousContext = session.requestContext()
621    if (previousContext?.provider !== requestContext.provider
622      || previousContext.model !== requestContext.model
623      || previousContext.contextWindow !== requestContext.contextWindow
624      || previousContext.systemPromptUpdate !== requestContext.systemPromptUpdate) {
625      session.append('request/context', requestContext)
626    }
627    signal.throwIfAborted()
630    deepFreeze(header)
631    const boundaryMessages = session.deriveMessages()   // 现在在此 derive
632    for (const message of boundaryMessages) {
633      if (this.frozenMessages.has(message)) continue
634      deepFreeze(message)
635      this.frozenMessages.add(message)
636    }
637    Object.freeze(boundaryMessages)
638    const request = markAgentLoopRequest(Object.freeze({
644    }))
645    return request     // 不再返回 preparedCall（它由 prepareRequest 单独返回）
646  }

62/** Remove adapter-derived values before plugins propose the next request config. */
63function requestProposal(header: EpochHeader): LlmCallConfig {
64  if (header.adapterDefaults === undefined) return header.config
65  const proposal = { ...header.config }
66  if (header.adapterDefaults.reasoningEffort === true) delete proposal.reasoningEffort
67  if (header.adapterDefaults.maxTokens === true) delete proposal.maxTokens
68  return proposal
69}

921  async prepareCall(config: LlmCallConfig, signal?: AbortSignal): Promise<PreparedLlmCall> {
922    const registration = this.registration(config.provider)
923    const adapterCall = await registration.adapter.prepareCall(config.provider, config.model, signal)
924    const modelInfo = this.normalizeModelInfo(registration, config.model, adapterCall.model)
925    const resolved = this.resolveCallWithInfo(config, modelInfo)
926    const resolvedConfig = deepFreeze(structuredClone(resolved.config))
927    const context = resolved.context === undefined ? undefined : deepFreeze(structuredClone(resolved.context))
930    const adapterDefaults = deepFreeze<LlmCallConfigAdapterDefaults>({标注哪些是 adapter 补的
931      ...config.reasoningEffort === undefined && resolvedConfig.reasoningEffort !== undefined
932        ? { reasoningEffort: true }
933        : {},
934      ...config.maxTokens === undefined && resolvedConfig.maxTokens !== undefined
935        ? { maxTokens: true }
936        : {},
937    })
938    let dispatched = false
939    return Object.freeze({
940      config: resolvedConfig,
941      retryPolicy: registration.retryPolicy,
942      adapterDefaults,
943      ...context === undefined ? {} : { context },
944      ...modelInfo.inputModalities === undefined
945        ? {}
946        : { inputModalities: Object.freeze([...modelInfo.inputModalities]) },
947      ...modelInfo.systemPromptUpdate === undefined ? {} : { systemPromptUpdate: ... },0.1.5 新增能力位
948      stream: (options: GenerateOptions): AsyncIterable<StreamChunk> => {
949        if (dispatched) {
950          throw new LlmError('a prepared LLM call can only be dispatched once', 'INVALID_PREPARED_CALL')
951        }
952        if (!callConfigEquals(options, resolvedConfig)) {
953          throw new LlmError(
954            'prepared LLM call config changed before adapter dispatch',
955            'INVALID_PREPARED_CALL',
956          )
957        }
958        dispatched = true
959        return this.streamWithRegistration(options, {
960          registration, config: resolvedConfig, modelInfo,
961          dispatch: options => adapterCall.stream(options),
962        })
963      },
964    })
965  }