oh-my-opencode/src/plugin/messages-transform.ts

import type { Message, Part } from "@opencode-ai/sdk"

import type { CreatedHooks } from "../create-hooks"

type MessageWithParts = {
  info: Message
  parts: Part[]
}

type MessagesTransformOutput = { messages: MessageWithParts[] }

export function createMessagesTransformHandler(args: {
  hooks: CreatedHooks
}): (input: Record<string, never>, output: MessagesTransformOutput) => Promise<void> {
  return async (input, output): Promise<void> => {
    await args.hooks.contextInjectorMessagesTransform?.[
      "experimental.chat.messages.transform"
    ]?.(input, output)

    await args.hooks.thinkingBlockValidator?.[
      "experimental.chat.messages.transform"
    ]?.(input, output)

    await args.hooks.toolPairValidator?.[
      "experimental.chat.messages.transform"
    ]?.(input, output)
  }
}