Vercel AI SDK + Neo4j Integration

npm install @ai-sdk/mcp

import { generateText, stepCountIs } from 'ai';
import { experimental_createMCPClient } from '@ai-sdk/mcp';

// Credentials passed per-request via Basic Auth header
const creds = Buffer.from(`${process.env.NEO4J_USERNAME}:${process.env.NEO4J_PASSWORD}`)
  .toString('base64');

const mcpClient = await experimental_createMCPClient({
  transport: {
    type:    'http',
    url:     `http://localhost:${process.env.MCP_PORT}/mcp`,
    headers: { Authorization: `Basic ${creds}` },
  },
});

const mcpTools = await mcpClient.tools();  // get-schema, read-cypher, write-cypher, ...

const { text, steps } = await generateText({
  model,
  system:   'You are a graph database assistant. Run get-schema first if unfamiliar.',
  prompt:   'How many organizations are in the database?',
  tools:    mcpTools,
  stopWhen: stepCountIs(10),   // AI SDK v6+ — replaces the removed maxSteps
});

await mcpClient.close();

Connected to Neo4j MCP ✓
Available tools: get-schema, list-gds-procedures, read-cypher, write-cypher

Query: How many organizations are in the database?

Result: There are 46,088 organizations in the database.
[Completed in 3 step(s)]

npm install neo4j-driver

import { generateText, tool, jsonSchema, stepCountIs } from 'ai';
import neo4j from 'neo4j-driver';

const driver = neo4j.driver(
  process.env.NEO4J_URI,
  neo4j.auth.basic(process.env.NEO4J_USERNAME, process.env.NEO4J_PASSWORD),
  { disableLosslessIntegers: true }
);

const getInvestments = tool({
  description: 'Returns investments made by a company.',
  inputSchema: jsonSchema({
    type: 'object',
    properties: {
      company: { type: 'string', description: 'Company or organization name' },
    },
    required: ['company'],
  }),
  execute: async ({ company }) => {
    const { records } = await driver.executeQuery(
      `MATCH (o:Organization)-[:HAS_INVESTOR]->(i)
       WHERE o.name = $company
       RETURN i.id AS id, i.name AS name, head(labels(i)) AS type`,
      { company },
      { database: process.env.NEO4J_DATABASE }
    );
    return records.map(r => r.toObject());
  },
});

// Merge custom tool with MCP tools — the framework routes each call automatically
const { text } = await generateText({
  model,
  prompt:   'Which companies did Google invest in?',
  tools:    { ...mcpTools, getInvestments },
  stopWhen: stepCountIs(10),
});

await driver.close();

Result: Google has made investments in several notable companies:
- Ionic Security
- Avere Systems
- FlexiDAO
- Cloudflare
- Trifacta
[Completed in 4 step(s)]

(:MemorySession {id})-[:HAS_MESSAGE]->(:MemoryMessage {role, content, timestamp})

import neo4j from 'neo4j-driver';

const memDriver = neo4j.driver(MEMORY_URI, neo4j.auth.basic(MEMORY_USER, MEMORY_PASS));

async function getRecentMessages(limit = 10) {
  const { records } = await memDriver.executeQuery(
    `MATCH (s:MemorySession {id: $sessionId})-[:HAS_MESSAGE]->(m:MemoryMessage)
     RETURN m.role AS role, m.content AS content
     ORDER BY m.timestamp ASC LIMIT $limit`,
    { sessionId: SESSION_ID, limit },
    { database: MEMORY_DB }
  );
  return records.map(r => `${r.get('role').toUpperCase()}: ${r.get('content')}`);
}

async function runWithMemory(query) {
  // BEFORE: inject conversation history into system prompt
  const history = await getRecentMessages();
  const systemWithContext = history.length
    ? `${SYSTEM_PROMPT}\n\n--- CONVERSATION HISTORY ---\n${history.join('\n')}\n----------------------------`
    : SYSTEM_PROMPT;

  const { text } = await generateText({
    model,
    system:   systemWithContext,
    prompt:   query,
    tools:    mcpTools,
    stopWhen: stepCountIs(10),
  });

  // AFTER: save interaction to memory graph
  await memDriver.executeQuery(
    `MERGE (s:MemorySession {id: $sessionId})
     CREATE (m:MemoryMessage {role: $role, content: $content, timestamp: datetime()})
     CREATE (s)-[:HAS_MESSAGE]->(m)`,
    { sessionId: SESSION_ID, role: 'user', content: query },
    { database: MEMORY_DB }
  );
  return text;
}

[USER]: I am conducting a competitive analysis of 'Google'. I am specifically
        worried about their subsidiaries and top-tier competitors in the AI space.
[AGENT]: Understood. I've noted that we're tracking Google for competitive intelligence...
 [Hook] Saving interaction to Neo4j memory graph...

--- Indexing memory (5s)... ---

[USER]: What are the main risks in the supply chain for the company I am currently tracking?
 ↳ Injecting 1 memories into context.
   Memory 1: Conducting competitive analysis of Google — focused on subsidiaries and AI competitors...
[AGENT]: Based on our ongoing analysis of Google, the main supply chain risks include...