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What it does

This example demonstrates the @grantex/vercel-ai integration by building scope-enforced tools with the Vercel AI SDK:
  1. Register an agent and obtain a grant token via the sandbox flow
  2. Create scoped tools using createGrantexTool with Zod schemas for typed parameters (calendar:read, email:send)
  3. Wrap tools with withAuditLogging to automatically log every execution to the Grantex audit trail
  4. Invoke tools via generateText (if OPENAI_API_KEY is set) or directly
  5. Demonstrate GrantexScopeError — attempting to create a tool with storage:delete (a scope not in the grant) throws a GrantexScopeError with requiredScope and grantedScopes properties
  6. Inspect the audit trail to see the logged actions

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Prerequisites

  • Node.js 18+
  • Docker (Docker Desktop or Docker Engine with Compose)

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Run

Start the local Grantex stack from the repository root: 
docker compose up --build
In a separate terminal, run the example: 
cd examples/vercel-ai-chatbot
npm install
npm start
To use a real LLM with generateText instead of direct tool invocation, set OPENAI_API_KEY: 
OPENAI_API_KEY=sk-... npm start

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Expected output

Without OPENAI_API_KEY (direct invocation): 
Agent registered: ag_01HXYZ...
Grant token received, grantId: grnt_01HXYZ...
Tools created: read_calendar, send_email
Audit logging attached

--- Invoking tools directly (no OPENAI_API_KEY set) ---
Calendar result: {"date":"today","events":[{"title":"Team standup","time":"9:00 AM"},{"title":"Design review","time":"2:00 PM"}]}
Email result: {"sent":true,"to":"alice@example.com","subject":"Today's events","bodyLength":49}

--- Testing scope enforcement ---
GrantexScopeError caught:
  Required scope:  storage:delete
  Granted scopes:  calendar:read, email:send

--- Audit trail ---
  [success] read_calendar — 2026-02-28T12:00:00.000Z
  [success] send_email — 2026-02-28T12:00:01.000Z

Done! Vercel AI integration demo complete.

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Environment variables

VariableDefaultDescription
GRANTEX_URLhttp://localhost:3001Base URL of the Grantex auth service
GRANTEX_API_KEYsandbox-api-key-localAPI key. Use a sandbox key for auto-approval
OPENAI_API_KEY(none)Optional. Set to use generateText with a real LLM

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Source code

The full source is in examples/vercel-ai-chatbot/src/index.ts.