@scopeblind/ai-sdk

Receipt-signing middleware for the Vercel AI SDK. Every generateText and streamText call produces an Ed25519-signed receipt capturing tool calls, model, usage, and timing.

Install

npm install @scopeblind/ai-sdk

Usage

import { wrapLanguageModel, generateText } from 'ai';
import { openai } from '@ai-sdk/openai';
import { receiptSigningMiddleware } from '@scopeblind/ai-sdk';

const middleware = receiptSigningMiddleware();

const model = wrapLanguageModel({
  model: openai('gpt-4o'),
  middleware,
});

const result = await generateText({
  model,
  prompt: 'What is the weather in SF?',
  tools: { /* ... */ },
});

// Receipt is attached to provider metadata
console.log(result.providerMetadata?.scopeblind);
// { receiptId: "sha256:a1b2...", publicKey: "...", sequence: 1 }

Persistence

const middleware = receiptSigningMiddleware({
  onReceipt: (receipt) => {
    // Append to file, send to dashboard, store in DB
    fs.appendFileSync('receipts.jsonl', JSON.stringify(receipt) + '\n');
  },
});

What Gets Signed

Each receipt captures:

• Tool calls: name, input hash (privacy-preserving), call ID
• Model: model ID, provider
• Usage: prompt/completion tokens
• Timing: duration in milliseconds
• Chain: sequence number + hash of previous receipt (tamper-evident ordering)

Verification

npx @veritasacta/verify receipts.jsonl --key <public_key_hex>

Privacy

Tool inputs are SHA-256 hashed by default. The receipt proves which tool was called without revealing the actual arguments. Set includeToolInputs: true to include raw inputs.

License

MIT

Built by ScopeBlind | protect-mcp | IETF Draft