https://noraincheck.github.io/tags/mcp/Recent content in MCP on NoRaincheckHugoen-USNoRaincheckTue, 01 Apr 2025 00:00:00 +0000https://noraincheck.github.io/posts/python-mcp-mounting-to-an-existing-fastapi-asgi-server/Tue, 01 Apr 2025 00:00:00 +0000https://noraincheck.github.io/posts/python-mcp-mounting-to-an-existing-fastapi-asgi-server/<h2 id="python-mcp---mounting-to-an-existing-fastapi-asgi-server">Python MCP - Mounting to an Existing FastAPI ASGI Server</h2> <p><em>April 2025</em></p> <p>You can mount the SSE server to an existing FastAPI ASGI server dynamically. The way I&rsquo;ve made it work is as follows:</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-py" data-lang="py"><span class="line"><span class="ln"> 1</span><span class="cl"><span class="n">sse</span> <span class="o">=</span> <span class="n">SseServerTransport</span><span class="p">(</span><span class="o">...</span><span class="p">)</span> </span></span><span class="line"><span class="ln"> 2</span><span class="cl"> </span></span><span class="line"><span class="ln"> 3</span><span class="cl"><span class="o">...</span> </span></span><span class="line"><span class="ln"> 4</span><span class="cl"><span class="n">app</span><span class="o">.</span><span class="n">router</span><span class="o">.</span><span class="n">routes</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">Mount</span><span class="p">(</span><span class="s2">&#34;/messages&#34;</span><span class="p">,</span> <span class="n">app</span><span class="o">=</span><span class="n">sse</span><span class="o">.</span><span class="n">handle_post_message</span><span class="p">))</span> </span></span><span class="line"><span class="ln"> 5</span><span class="cl"> </span></span><span class="line"><span class="ln"> 6</span><span class="cl"><span class="nd">@app.get</span><span class="p">(</span><span class="s2">&#34;/sse&#34;</span><span class="p">)</span> </span></span><span class="line"><span class="ln"> 7</span><span class="cl"><span class="k">async</span> <span class="k">def</span> <span class="nf">handle_mcp_connection</span><span class="p">(</span><span class="n">request</span><span class="p">:</span> <span class="n">Request</span><span class="p">):</span> </span></span><span class="line"><span class="ln"> 8</span><span class="cl"> <span class="k">async</span> <span class="k">with</span> <span class="n">sse</span><span class="o">.</span><span class="n">connect</span><span class="p">(</span><span class="n">sse</span><span class="p">(</span><span class="n">request</span><span class="o">.</span><span class="n">scope</span><span class="p">,</span> <span class="n">request</span><span class="o">.</span><span class="n">receive</span><span class="p">,</span> <span class="n">request</span><span class="o">.</span><span class="n">send</span><span class="p">)</span> <span class="k">as</span> <span class="p">(</span> </span></span><span class="line"><span class="ln"> 9</span><span class="cl"> <span class="n">read_stream</span><span class="p">,</span> </span></span><span class="line"><span class="ln">10</span><span class="cl"> <span class="n">write_stream</span><span class="p">,</span> </span></span><span class="line"><span class="ln">11</span><span class="cl"> <span class="p">):</span> </span></span><span class="line"><span class="ln">12</span><span class="cl"> <span class="k">await</span> <span class="n">mcp</span><span class="o">.</span><span class="n">_mcp_server</span><span class="o">.</span><span class="n">run</span><span class="p">(</span> </span></span><span class="line"><span class="ln">13</span><span class="cl"> <span class="n">read_stream</span><span class="p">,</span> </span></span><span class="line"><span class="ln">14</span><span class="cl"> <span class="n">write_stream</span><span class="p">,</span> </span></span><span class="line"><span class="ln">15</span><span class="cl"> <span class="n">mcp</span><span class="o">.</span><span class="n">_mcp_server</span><span class="o">.</span><span class="n">create_initialization_options</span><span class="p">(),</span> </span></span><span class="line"><span class="ln">16</span><span class="cl"> <span class="p">)</span> </span></span></code></pre></div><p>This seemed to work pretty well, along with having Redis as an intermediary broker for dealing with state.</p>