Hooks

Where it lives

• hooks/session-start.mjsRunsGitHub ↗
  Read the script

  #!/usr/bin/env node
  /**
   * SessionStart hook for 97 plugin.
   *
   * Reads skills/using-97/SKILL.md, strips frontmatter (matching the OpenCode
   * adapter for cross-harness consistency), and emits the platform-appropriate
   * context-injection JSON on stdout.
   *
   * Output shape:
   *   - Claude Code (default):
   *       { hookSpecificOutput: { hookEventName: "SessionStart",
   *                                additionalContext: "..." } }
   *   - Copilot CLI (when COPILOT_CLI env var is set, any non-empty value):
   *       { additionalContext: "..." }
   *
   * Cursor is intentionally not supported — see CONTRIBUTE.md harness
   * scope policy. Add a new harness adapter only after content evidence
   * justifies the scope expansion.
   *
   * Zero deps, Node built-ins only. Invoked directly via `node` from
   * hooks/hooks.json so it works on Linux, macOS, and Windows without
   * relying on a POSIX shell.
   */
  
  import fs from 'fs';
  import path from 'path';
  import { fileURLToPath } from 'url';
  
  const __dirname = path.dirname(fileURLToPath(import.meta.url));
  const skillPath = path.resolve(__dirname, '..', 'skills', 'using-97', 'SKILL.md');
  
  // Strip frontmatter to mirror .opencode/plugins/97.js behavior. CRLF-tolerant
  // for Windows checkouts.
  function stripFrontmatter(content) {
    const m = content.match(/^---\r?\n[\s\S]*?\r?\n---\r?\n([\s\S]*)$/);
    return m ? m[1] : content;
  }
  
  let body = '';
  try {
    const raw = fs.readFileSync(skillPath, 'utf8');
    body = stripFrontmatter(raw);
  } catch (err) {
    // Fail loud on stderr; emit empty-context JSON so the harness still
    // gets a parseable object rather than a crash.
    process.stderr.write(`97 session-start: failed to read ${skillPath}: ${err.message}\n`);
  }
  
  const sessionContext = `<bootstrap name="using-97">
  ${body}
  </bootstrap>`;
  
  const isCopilot = !!process.env.COPILOT_CLI;
  const payload = isCopilot
    ? { additionalContext: sessionContext }
    : {
        hookSpecificOutput: {
          hookEventName: 'SessionStart',
          additionalContext: sessionContext,
        },
      };
  
  process.stdout.write(JSON.stringify(payload, null, 2) + '\n');
  

Read the script before you install anything that runs on your machine. This is the one part of a plugin that acts without being asked.