claude-sessions-mcp

Instructions

Implementation Reference

• src/mcp/index.ts:38-53 (registration)

  Tool registration for 'rename_session', including input schema using Zod and the handler function that calls the core renameSession implementation.

  server.tool(
    'rename_session',
    'Rename a session by adding a title prefix to the first message',
    {
      project_name: z.string().describe('Project folder name'),
      session_id: z.string().describe('Session ID (filename without .jsonl)'),
      new_title: z.string().describe('New title to add as prefix'),
    },
    async ({ project_name, session_id, new_title }) => {
      const result = await Effect.runPromise(
        session.renameSession(project_name, session_id, new_title)
      )
      return {
        content: [{ type: 'text', text: JSON.stringify(result, null, 2) }],
      }
    }

• src/lib/session.ts:145-172 (handler)

  Core implementation of renameSession: reads the session JSONL file, modifies the first message's content by prepending the new title in brackets (replacing any existing prefix), and writes back the updated file.

  export const renameSession = (projectName: string, sessionId: string, newTitle: string) =>
    Effect.gen(function* () {
      const filePath = path.join(getSessionsDir(), projectName, `${sessionId}.jsonl`)
      const content = yield* Effect.tryPromise(() => fs.readFile(filePath, 'utf-8'))
      const lines = content.trim().split('\n').filter(Boolean)
  
      if (lines.length === 0) {
        return { success: false, error: 'Empty session' }
      }
  
      const messages = lines.map((line) => JSON.parse(line) as Message)
      const firstMsg = messages[0]
  
      // Add title prefix to first message
      if (firstMsg && typeof firstMsg.message === 'object' && firstMsg.message !== null) {
        const msg = firstMsg.message as { content?: string }
        if (msg.content) {
          // Remove existing title prefix if any
          const cleanContent = msg.content.replace(/^\[.*?\]\s*/, '')
          msg.content = `[${newTitle}] ${cleanContent}`
        }
      }
  
      const newContent = messages.map((m) => JSON.stringify(m)).join('\n') + '\n'
      yield* Effect.tryPromise(() => fs.writeFile(filePath, newContent, 'utf-8'))
  
      return { success: true }
    })

• src/mcp/index.ts:42-45 (schema)

  Zod schema defining input parameters for the rename_session tool.

    project_name: z.string().describe('Project folder name'),
    session_id: z.string().describe('Session ID (filename without .jsonl)'),
    new_title: z.string().describe('New title to add as prefix'),
  },