>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3585599. --> Reported by: [e0ipso](https://www.drupal.org/user/550110) Related to !13 >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p> The mcp_server module currently pins <code>mcp/sdk</code> to ^0.1.0 in composer.json. Upstream has since released v0.2.x, v0.3.x, and v0.4.0 (2026-02-23), carrying bug fixes, new MCP spec features, and API improvements. Because the SDK is pre-1.0, each minor bump is allowed to include breaking changes, which is why we are stuck on the initial release line.</p> <p> Pinning to <code>^0.1.0</code> blocks the module from:</p> <ul> <li> Adopting upstream fixes and newer MCP spec capabilities.</li> <li> Coexisting with other Drupal projects that require a newer mcp/sdk.</li> <li> Receiving security and maintenance updates that only land on the current release line.</li> </ul> <h3 id="summary-proposed-resolution">Proposed resolution</h3> <ol> <li> Audit every <code>Mcp\&hellip;</code> usage in mcp_server, mcp_server_oauth, <code>mcp_server_tool_bridge</code>, <code>mcp_server_ui</code>, and <code>mcp_server_examples</code> against the v0.4.0 API surface.</li> <li> Update <code>composer.json</code> to require the latest stable line (^0.4.0, or a constraint covering what we verify).</li> <li> Fix compile/runtime fallout from renamed/removed SDK classes, method signatures, DTO shapes, and transport changes between 0.1 &rarr; 0.4.</li> <li> Re-run the full test matrix (phpunit, phpcs, phpstan) and exercise HTTP /_mcp and Drush STDIO</li> <li> transports against a real client.</li> </ol>