Keyway MCP Server

Instructions

Implementation Reference

• src/tools/inject-run.ts:78-195 (handler)

  The main handler function `injectRun` implements the logic for the `keyway_inject_run` tool by pulling secrets, merging them into the environment, executing the requested command, and sanitizing the output.

  export async function injectRun(args: {
    command: string;
    args?: string[];
    environment?: string;
    timeout?: number;
  }): Promise<CallToolResult> {
    // Validate command is not empty
    if (!args.command || !args.command.trim()) {
      return {
        content: [{ type: 'text', text: 'Error: command is required' }],
        isError: true,
      };
    }
  
    const token = await getToken();
    const repository = getRepository();
    const environment = args.environment || 'development';
    const timeout = Math.min(args.timeout || DEFAULT_TIMEOUT_MS, DEFAULT_TIMEOUT_MS); // Cap at 5 min
  
    // Pull secrets
    const content = await pullSecrets(repository, environment, token);
    const secrets = parseEnvContent(content);
  
    // Merge secrets with current environment
    const env = { ...process.env, ...secrets };
  
    // Run command with secrets injected
    const result = await new Promise<{
      exitCode: number;
      stdout: string;
      stderr: string;
      stdoutTruncated: boolean;
      stderrTruncated: boolean;
    }>((resolve, reject) => {
      const child = spawn(args.command, args.args || [], {
        cwd: process.cwd(),
        env,
        shell: false, // Prevent shell injection
        stdio: ['ignore', 'pipe', 'pipe'],
      });
  
      let stdout = '';
      let stderr = '';
      let stdoutBytes = 0;
      let stderrBytes = 0;
  
      const timer = setTimeout(() => {
        child.kill('SIGTERM');
        // Give process time to cleanup, then force kill
        setTimeout(() => child.kill('SIGKILL'), 5000);
        reject(new Error(`Command timed out after ${timeout / 1000}s`));
      }, timeout);
  
      child.stdout.on('data', (data: Buffer) => {
        // Limit memory usage by stopping accumulation after max size
        if (stdoutBytes < MAX_OUTPUT_BYTES) {
          stdout += data.toString();
          stdoutBytes += data.length;
        }
      });
  
      child.stderr.on('data', (data: Buffer) => {
        if (stderrBytes < MAX_OUTPUT_BYTES) {
          stderr += data.toString();
          stderrBytes += data.length;
        }
      });
  
      child.on('close', (code) => {
        clearTimeout(timer);
  
        // Truncate and mask output
        const stdoutResult = truncateOutput(stdout, MAX_OUTPUT_BYTES);
        const stderrResult = truncateOutput(stderr, MAX_OUTPUT_BYTES);
  
        resolve({
          exitCode: code ?? 1,
          stdout: maskSecrets(stdoutResult.text, secrets),
          stderr: maskSecrets(stderrResult.text, secrets),
          stdoutTruncated: stdoutResult.truncated || stdoutBytes >= MAX_OUTPUT_BYTES,
          stderrTruncated: stderrResult.truncated || stderrBytes >= MAX_OUTPUT_BYTES,
        });
      });
  
      child.on('error', (err) => {
        clearTimeout(timer);
        reject(new Error(`Failed to execute command: ${err.message}`));
      });
    });
  
    const response: Record<string, unknown> = {
      exitCode: result.exitCode,
      stdout: result.stdout,
      stderr: result.stderr,
      secretsInjected: Object.keys(secrets).length,
    };
  
    // Include truncation warnings if applicable
    if (result.stdoutTruncated || result.stderrTruncated) {
      response.warnings = [];
      if (result.stdoutTruncated) {
        (response.warnings as string[]).push('stdout was truncated (exceeded 1MB)');
      }
      if (result.stderrTruncated) {
        (response.warnings as string[]).push('stderr was truncated (exceeded 1MB)');
      }
    }
  
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(response, null, 2),
        },
      ],
      isError: result.exitCode !== 0,
    };
  }