Cryptographic provenance
for AI outputs
Sign outputs from Claude, OpenAI, or any AI model with independently verifiable receipts. When a customer disputes, a regulator asks, or a lawsuit lands — you have cryptographic evidence designed for admissibility under FRE 902.
100 signings/month free. Then $0.01/signing. No subscription.
AI detection is losing. Provenance is winning.
Every new model release breaks the detectors. Cryptographic signatures don't care how good the model gets.
AI detection
- Infers from writing patterns. ~50% accuracy on modern models.
- Flags human writing as AI. Flags AI writing as human.
- Degrades with every model release.
- Courts and regulators don't accept statistical inference as proof.
AI provenance
- Cryptographic signature at creation. Not inference — proof.
- 100% accuracy when signed. Doesn't degrade over time.
- Three-layer timestamp: CertNode + RFC 3161 TSA + optional Bitcoin anchor.
- Designed for court admissibility under FRE 902(13)/(14).
How it works
One SDK call. Every AI output signed with an independent cryptographic receipt.
import { CertNode } from '@certnode/sdk'
import Anthropic from '@anthropic-ai/sdk'
const claude = new Anthropic()
const cert = new CertNode({ apiKey: process.env.CERTNODE_KEY })
const response = await claude.messages.create({
model: 'claude-opus-4-7',
messages: [{ role: 'user', content: 'Write marketing copy' }]
})
// One extra line signs the output with provenance
const signed = await cert.signAIOutput({
output: response.content[0].text,
model: 'claude-opus-4-7',
provider: 'anthropic',
})
// signed.receiptId -> verifiable at certnode.io/verify/[id]What you get
Three-layer timestamps
CertNode internal timestamp + RFC 3161 from an independent Time Stamping Authority + optional Bitcoin anchor via OpenTimestamps. Three independent verification paths on every signature.
Platform-agnostic
REST API works with Claude, OpenAI, Mistral, Llama, or any model. MCP server for Claude-native integration. npm SDK for TypeScript and Node. Works wherever you generate content.
Court-ready evidence
Designed for admissibility under FRE 902(13)/(14) self-authenticating digital evidence. Optional PDF evidence package with chain-of-custody framing for disputes or regulatory requests.
Pay-as-you-go pricing
No subscription. No tiers to predict. 100 signings every month free. Then $0.01 per signing with automatic volume discounts as you grow.
| Monthly volume | Price per signing |
|---|---|
| 0 to 100 signings | Free |
| 100 to 10,000 signings | $0.010 |
| 10,000 to 100,000 signings | $0.007 |
| 100,000 to 1,000,000 signings | $0.004 |
| 1,000,000+ signings | $0.002 |
| Enterprise (annual prepay) | Contact sales |
Verifications are free
Anyone can verify a CertNode signature at no cost, with no account required.
Volume discounts auto-apply
Your rate drops automatically as your monthly volume grows. No tier migration or sales call required.
Pay only for what you use
No subscription. A training-data run that signs 500k in one week, then nothing for a month, pays for exactly 500k.
Sign your first AI output in under 5 minutes.
Sign up with email. No card required for the free tier. Get your API key and start signing.