// bridgeHttp.ts
import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { StreamableHTTPClientTransport }
from "@modelcontextprotocol/sdk/client/streamableHttp.js";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
export async function bridgeHttp(
hub : McpServer,
url : string,
prefix: string,
apiKey?: string // optional arg ➊
) {
// auto-detect: "GITHUB_API_KEY", "BRAVE_API_KEY", …
if (!apiKey) {
const envVar = `${prefix.toUpperCase()}_API_KEY`;
apiKey = process.env[envVar];
}
const transport = new StreamableHTTPClientTransport(
new URL(url),
apiKey
? { requestInit: { headers: { Authorization: `Bearer ${apiKey}` } } }
: undefined
);
/* 2️⃣ open client session */
const client = new Client({ name: `bridge-${prefix}`, version: "0.1" });
await client.connect(transport);
/* 3️⃣ pull catalog */
const { tools } = await client.listTools();
const { prompts } = await client.listPrompts().catch(() => ({ prompts: [] }));
/* 3️⃣ re-expose every tool */
// Helper function to convert JSON schema properties to Zod schema shape
function jsonSchemaToZodShape(jsonSchema: any): Record<string, any> {
if (!jsonSchema?.properties) {
return {};
}
const shape: Record<string, any> = {};
for (const [key, prop] of Object.entries(jsonSchema.properties as Record<string, any>)) {
// Convert JSON schema types to Zod types
switch (prop.type) {
case 'string':
shape[key] = z.string();
break;
case 'number':
shape[key] = z.number();
break;
case 'integer':
shape[key] = z.number().int();
break;
case 'boolean':
shape[key] = z.boolean();
break;
case 'array':
shape[key] = z.array(z.any());
break;
case 'object':
shape[key] = z.object({}).passthrough();
break;
default:
shape[key] = z.any();
}
// Make optional if not in required array
if (!jsonSchema.required?.includes(key)) {
shape[key] = shape[key].optional();
}
// Add description if available
if (prop.description) {
shape[key] = shape[key].describe(prop.description);
}
}
return shape;
}
for (const t of tools as any[]) {
// 1) Convert JSON schema to Zod schema shape
const zodShape = jsonSchemaToZodShape(t.inputSchema);
// 2) Build the Zod schema
const schema = z.object(zodShape).passthrough();
console.log(`[bridge] tool ${t.name} schema shape:`, zodShape);
console.log(`[bridge] tool ${t.name} input schema:`, t.inputSchema);
// 3) Pull description into annotations
const annotations = {
...(t.annotations ?? {}),
description: t.description ?? t.name,
openWorldHint: true,
};
// 3) call the 4-arg overload: name, schema, annotations, handler
hub.tool(
`${prefix}/${t.name}`,
schema.shape,
annotations,
async (args: any, _extra: any) => {
console.log("[bridge] args =", args); // ← will now show { query: "react", … }
console.log(`[bridge] → ${t.name} with `, _extra);
try {
/* call the upstream tool (30-s per-call timeout) */
const result = await client.callTool(
{ name: t.name, arguments: args}
);
console.log(`[bridge] ← ${t.name} OK with `, result);
return result as any; // return the result as-is
} catch (e) {
/* log & surface the error without crashing the hub */
console.error(`[bridge] ← ${t.name} ERROR`, e);
return {
content: [
{
type: "text",
text:
e instanceof Error
? e.message
: String(e ?? "unknown error"),
},
],
isError: true,
};
}
},
);
}
console.log(`🔗 bridged HTTP ${url} → "${prefix}/…"`);
}
