Codex MCP Server

Instructions

Implementation Reference

• src/tools/handlers.ts:214-251 (handler)

  Handler implementation for listSessions tool.

  export class ListSessionsToolHandler {
    constructor(private sessionStorage: SessionStorage) {}
  
    async execute(args: unknown): Promise<ToolResult> {
      try {
        ListSessionsToolSchema.parse(args);
  
        const sessions = this.sessionStorage.listSessions();
        const sessionInfo = sessions.map((session) => ({
          id: session.id,
          createdAt: session.createdAt.toISOString(),
          lastAccessedAt: session.lastAccessedAt.toISOString(),
          turnCount: session.turns.length,
        }));
  
        return {
          content: [
            {
              type: 'text',
              text:
                sessionInfo.length > 0
                  ? JSON.stringify(sessionInfo, null, 2)
                  : 'No active sessions',
            },
          ],
        };
      } catch (error) {
        if (error instanceof ZodError) {
          throw new ValidationError(TOOLS.LIST_SESSIONS, error.message);
        }
        throw new ToolExecutionError(
          TOOLS.LIST_SESSIONS,
          'Failed to list sessions',
          error
        );
      }
    }
  }

• src/types.ts:55-55 (schema)

  Zod schema for listSessions tool input arguments.

  export const ListSessionsToolSchema = z.object({});

• src/tools/handlers.ts:260-260 (registration)

  Registration of the listSessions handler in the tools registry.

  [TOOLS.LIST_SESSIONS]: new ListSessionsToolHandler(sessionStorage),