MCP Support in OpenKBS
December 21, 2025
While OpenKBS provides full control over context and custom tool syntax, MCP (Model Context Protocol) has become the de facto standard for AI tool integration. With MCP support, OpenKBS auto-discovers tools from any MCP server and generates context automatically - tool names, descriptions, and parameter schemas are injected into the system prompt without manual documentation.
Connect Any MCP Server
app/settings.json:{
"options": {
"mcpServerUrl": "https://your-mcp-server.com",
"mcpServers": {
"your-server": {}
}
}
}Use any MCP-compatible endpoint. See MCP server list.SDK
await openkbs.mcp.callTool('your-server', 'tool_name', { ...args });
await openkbs.mcp.listTools('your-server');
await openkbs.mcp.listServers();How It Works
1. On first chat, OpenKBS calls
2. Tool schemas (names, descriptions, parameters) are injected into system prompt
3. Agent outputs:
4. Handler calls
tools/list on each MCP server2. Tool schemas (names, descriptions, parameters) are injected into system prompt
3. Agent outputs:
<mcp_{server}_{tool}>{JSON}</mcp_{server}_{tool}>4. Handler calls
openkbs.mcp.callTool()Caching
Tool schemas are cached for 24 hours to avoid repeated discovery calls.
Cache auto-refreshes when:
• 24 hours passed
•
•
Update your config → new tools discovered on next chat. No restart needed.
Cache auto-refreshes when:
• 24 hours passed
•
mcpServers config changed (add/remove servers)•
mcpServerUrl changedUpdate your config → new tools discovered on next chat. No restart needed.
Handler
A single universal handler in
Note: This handler is included in the default OpenKBS app template. New agents created via
src/Events/actions.js enables all MCP tools from one place:[/<mcp_([a-z0-9-]+)_([a-z0-9_]+)>([\s\S]*?)<\/mcp_\1_\2>/s, async (match) => {
try {
const server = match[1];
const toolName = match[2];
const args = match[3].trim() ? JSON.parse(match[3].trim()) : {};
const result = await openkbs.mcp.callTool(server, toolName, args);
return {
type: 'MCP_RESULT',
server,
tool: toolName,
data: result?.content || [],
_meta_actions: ['REQUEST_CHAT_MODEL']
};
} catch (e) {
return {
type: 'MCP_ERROR',
error: e.message,
_meta_actions: ['REQUEST_CHAT_MODEL']
};
}
}]Note: This handler is included in the default OpenKBS app template. New agents created via
Create App have it already. Older agents created before MCP integration may need to add this handler to their actions.js manually.Links
