Function createUserMessage

packages/arctic/src/session/prompt.ts:1019–1305

(input: PromptInput)

  }

  async function createUserMessage(input: PromptInput) {
    const agent = await Agent.get(input.agent ?? "build")
    const info: MessageV2.Info = {
      id: input.messageID ?? Identifier.ascending("message"),
      role: "user",
      sessionID: input.sessionID,
      time: {
        created: Date.now(),
      },
      tools: input.tools,
      system: input.system,
      agent: agent.name,
      model: input.model ?? agent.model ?? (await lastModel(input.sessionID)),
      thinkingLevel: input.thinkingLevel,
    }

    const parts = await Promise.all(
      input.parts.map(async (part): Promise<MessageV2.Part[]> => {
        if (part.type === "file") {
          const url = new URL(part.url)
          switch (url.protocol) {
            case "data:":
              if (part.mime === "text/plain") {
                return [
                  {
                    id: Identifier.ascending("part"),
                    messageID: info.id,
                    sessionID: input.sessionID,
                    type: "text",
                    synthetic: true,
                    text: `Called the Read tool with the following input: ${JSON.stringify({ filePath: part.filename })}`,
                  },
                  {
                    id: Identifier.ascending("part"),
                    messageID: info.id,
                    sessionID: input.sessionID,
                    type: "text",
                    synthetic: true,
                    text: Buffer.from(part.url, "base64url").toString(),
                  },
                  {
                    ...part,
                    id: part.id ?? Identifier.ascending("part"),
                    messageID: info.id,
                    sessionID: input.sessionID,
                  },
                ]
              }
              break
            case "file:":
              log.info("file", { mime: part.mime })
              // have to normalize, symbol search returns absolute paths
              // Decode the pathname since URL constructor doesn't automatically decode it
              const filepath = fileURLToPath(part.url)
              const stat = await Bun.file(filepath).stat()

              if (stat.isDirectory()) {
                part.mime = "application/x-directory"