Sol MCP App

Sol MCP is a read-only ChatGPT App facade over the existing Sol APIs.

Public endpoint

App URL: https://sol.system42.one/api/mcp/sol
Health URL: https://sol.system42.one/api/mcp/sol/health
Legacy SSE URL: https://sol.system42.one/api/mcp/sol/sse

ChatGPT App creation settings

These are the settings that matched the live connector behavior during ChatGPT-side registration:

Name: Sol
Description: Read-only grounded chat, search, fetch, and live status
MCP Server URL: https://sol.system42.one/api/mcp/sol
Authentication: No Auth

Important notes from live registration attempts:

Mixed and OAuth are wrong for this connector. ChatGPT explicitly reported that the Sol MCP endpoint does not implement OAuth.
https://sol.system42.one/api/mcp/sol/sse is not the right connector URL for ChatGPT app creation. The creation flow timed out against the SSE endpoint because it is a legacy long-lived transport rather than the primary MCP entrypoint.
The root MCP URL is the intended connector URL for ChatGPT app registration.
After creation, the connector may not appear immediately in the public browse grid. The authoritative verification is whether @Sol resolves in chat and successfully calls tools.

Local service

Local port: 127.0.0.1:8898
Source: /home/david/random/apps/sol-mcp/server.mjs
Unit: /home/david/.config/systemd/user/sol-mcp.service

Exposed tools

- search
Search the Sol knowledge index and return compact document handles.
- fetch
Read a full Sol document by id returned from search.
- queryKnowledge
Return scored semantic-search hits from the Sol knowledge API.
- queryChat
Run a grounded text chat turn against the Sol chat API.
- getSystemStatus
Return current Sol runtime health, telemetry, and service state.

Operational notes

The MCP layer is intentionally read-only.
Sol GPT Actions and ChatGPT Apps are separate attachment models. Keep the GPT as the personality/orchestration surface and the MCP app as the capability surface.
The MCP server proxies to the existing Sol services:
chat: 127.0.0.1:8895
knowledge: 127.0.0.1:8892
dashboard: 127.0.0.1:8896
Live connector verification succeeded when ChatGPT resolved @Sol and invoked the Query Chat tool from a normal conversation.
queryChat normalizes ChatGPT-style wrapped prompts such as The user says: '@Sol hello'. Respond with a brief greeting. down to the underlying user intent before forwarding them.
queryChat always fetches live status before answering; greeting and server-status turns defer to the Sol chat API's native live-site-state path, while other turns get the live traffic/sensor/runtime block merged into page context.
Sensor readouts are part of the shared live context, not a separate optional tool-only detail.

Deploy / reload

bash
systemctl --user daemon-reload
systemctl --user enable --now sol-mcp.service
systemctl --user restart sol-mcp.service
systemctl --user reload caddy-sol37.service

Smoke test

bash
curl -s https://sol.system42.one/api/mcp/sol/health | python3 -m json.tool

SDK-level smoke test:

bash
node --input-type=module <<'EOF'
import { Client } from '@modelcontextprotocol/sdk/client/index.js';
import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/streamableHttp.js';
const transport = new StreamableHTTPClientTransport(new URL('https://sol.system42.one/api/mcp/sol'));
const client = new Client({ name: 'sol-mcp-smoke', version: '0.1.0' }, { capabilities: {} });
await client.connect(transport);
console.log((await client.listTools()).tools.map(tool => tool.name));
await transport.close();
EOF

Sol Mcp App

Executive Summary