{"version":"2.1.261","anchor":"new-sdk-launch-flag-await-initialize","canonical_anchor":"new-sdk-launch-flag-await-initialize","heading":"New SDK launch flag: --await-initialize","tier":"use","area":"SDK","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.261\/e\/new-sdk-launch-flag-await-initialize","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.261","markdown":"### New SDK launch flag: --await-initialize\n\nA new SDK CLI flag makes the process wait for an initialize request over stdin before starting.\n\nThe Claude Agent SDK CLI has a new `--await-initialize` flag that makes the process block at startup and read the first stdin line as an `initialize` control request, applying its launch-scoped fields (currently `plugins`) the same way `--plugin-dir`\/`--plugin-dir-no-mcp` would. It requires `--input-format=stream-json`, cannot be combined with `--sdk-url`, and only applies when stdin isn't a TTY. Startup fails with a descriptive error if the first line isn't valid JSON, isn't an initialize request, or never arrives before the wait times out.\n\n- Area: SDK\n- Names: `--plugin-dir`\n- Tier: Use it now\n- Useful: 4\/5\n- Signal: 2\/5"}