claude-sessions-mcp

Instructions

Implementation Reference

• src/mcp/index.ts:138-151 (registration)

  Registers the 'get_session_files' MCP tool, including input schema (project_name, session_id) and thin handler that delegates to session.getSessionFiles
  server.tool( 'get_session_files', 'Get list of all files changed in a session (from file-history-snapshot and tool_use)', { project_name: z.string().describe('Project folder name'), session_id: z.string().describe('Session ID'), }, async ({ project_name, session_id }) => { const result = await Effect.runPromise(session.getSessionFiles(project_name, session_id)) return { content: [{ type: 'text', text: JSON.stringify(result, null, 2) }], } } )
• src/lib/session.ts:260-325 (handler)

  Core implementation of getSessionFiles: parses session messages, extracts unique file changes from 'file-history-snapshot' and 'tool_use' (Write/Edit) blocks
  export const getSessionFiles = (projectName: string, sessionId: string) => Effect.gen(function* () { const messages = yield* readSession(projectName, sessionId) const fileChanges: FileChange[] = [] const seenFiles = new Set<string>() for (const msg of messages) { // Check for file-history-snapshot type if (msg.type === 'file-history-snapshot') { const snapshot = msg as unknown as { type: string messageId?: string snapshot?: { trackedFileBackups?: Record<string, unknown> timestamp?: string } } const backups = snapshot.snapshot?.trackedFileBackups if (backups && typeof backups === 'object') { for (const filePath of Object.keys(backups)) { if (!seenFiles.has(filePath)) { seenFiles.add(filePath) fileChanges.push({ path: filePath, action: 'modified', timestamp: snapshot.snapshot?.timestamp, messageUuid: snapshot.messageId ?? msg.uuid, }) } } } } // Also check tool_use for Write/Edit operations if (msg.type === 'assistant' && msg.message) { const assistantMsg = msg.message as { content?: Array<{ type: string; name?: string; input?: { file_path?: string } }> } const content = assistantMsg.content if (Array.isArray(content)) { for (const block of content) { if (block.type === 'tool_use' && (block.name === 'Write' || block.name === 'Edit')) { const filePath = block.input?.file_path if (filePath && !seenFiles.has(filePath)) { seenFiles.add(filePath) fileChanges.push({ path: filePath, action: block.name === 'Write' ? 'created' : 'modified', timestamp: msg.timestamp, messageUuid: msg.uuid, }) } } } } } } return { sessionId, projectName, files: fileChanges, totalChanges: fileChanges.length, } satisfies SessionFilesSummary })
• src/lib/session.ts:252-257 (schema)

  TypeScript interface defining the output structure of getSessionFiles
  export interface SessionFilesSummary { sessionId: string projectName: string files: FileChange[] totalChanges: number }
• src/lib/session.ts:104-110 (helper)

  Helper function readSession loads and parses session messages from .jsonl file, used by getSessionFiles
  export const readSession = (projectName: string, sessionId: 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) return lines.map((line) => JSON.parse(line) as Message) })
• src/mcp/index.ts:142-144 (schema)

  Zod input schema for the MCP tool parameters
  project_name: z.string().describe('Project folder name'), session_id: z.string().describe('Session ID'), },