Function stripToolSearchFieldsFromMessages

src/services/tokenEstimation.ts:66–122

* Strip tool search-specific fields from messages before sending for token counting. * This removes 'caller' from tool_use blocks and 'tool_reference' from tool_result content. * These fields are only valid with the tool search beta and will cause errors otherwise. * * Note: We use 'as unknown a

(
  messages: Anthropic.Beta.Messages.BetaMessageParam[],
)

 * but at runtime these fields may exist from API responses when tool search was enabled.
 */
function stripToolSearchFieldsFromMessages(
  messages: Anthropic.Beta.Messages.BetaMessageParam[],
): Anthropic.Beta.Messages.BetaMessageParam[] {
  return messages.map(message => {
    if (!Array.isArray(message.content)) {
      return message
    }

    const normalizedContent = message.content.map(block => {
      // Strip 'caller' from tool_use blocks (assistant messages)
      if (block.type === 'tool_use') {
        // Destructure to exclude any extra fields like 'caller'
        const toolUse =
          block as Anthropic.Beta.Messages.BetaToolUseBlockParam & {
            caller?: unknown
          }
        return {
          type: 'tool_use' as const,
          id: toolUse.id,
          name: toolUse.name,
          input: toolUse.input,
        }
      }

      // Strip tool_reference blocks from tool_result content (user messages)
      if (block.type === 'tool_result') {
        const toolResult =
          block as Anthropic.Beta.Messages.BetaToolResultBlockParam
        if (Array.isArray(toolResult.content)) {
          const filteredContent = (toolResult.content as unknown[]).filter(
            c => !isToolReferenceBlock(c),
          ) as typeof toolResult.content

          if (filteredContent.length === 0) {
            return {
              ...toolResult,
              content: [{ type: 'text' as const, text: '[tool references]' }],
            }
          }
          if (filteredContent.length !== toolResult.content.length) {
            return {
              ...toolResult,
              content: filteredContent,
            }
          }
        }
      }

      return block
    })

    return {
      ...message,
      content: normalizedContent,
    }
  })
}