What does affixio prove locally?
UltraHonk zero-knowledge proofs over bundled Noir circuits such as simple_yesno and yesno via Barretenberg (@aztec/bb.js). Proof generation stays on your host before sync.
Start with 100 free AffixIO proofs
New eligible Hub account holders can claim one allocation of 100 free SDK proofs. No card required. Use them to test SDK proofs, agent verification, agentic payment checks and transaction intent proof workflows.
See the free proof offeraffixio
AffixIO SDK 2.0.3 for Node.js
Generate proofs on your host, verify defined checks and retain signed evidence. Choose UltraHonk or HMAC mode for the verification your integration requires.
Install
npm install affixioRequires Node.js 20+. API base defaults to https://api.affix-io.com.
What you get
- Local ZK prove with bundled Noir circuits (simple_yesno, yesno) over Barretenberg UltraHonk.
- Production sync with AffixIO ML-DSA-65 on the verify payload.
- Merkle audit with client batches up to 50,000 digests.
- Offline-first queue with configurable auto-flush.
- PII-free QR and barcode carriers. Presentment links use your host base only.
- Pluggable storage for JSON, Redis, SQL, or custom get/set backends.
Minimal setup
import { AffixSDK } from "affixio";const sdk = new AffixSDK({ apiKey: process.env.AFFIX_API_KEY });Modes
- auto: live AffixIO when reachable, otherwise offline local prove if allowed.
- offline: always local prove and enqueue.
- online: live licence required. ZK still runs locally.
affixio questions
UltraHonk prove, storage, Merkle batches, offline queue.
What storage backends does the SDK support?
JSON under .affix/ by default, plus pluggable Redis, SQL, or custom get/set backends for document and queue storage.
What is the Merkle batch limit?
Client batches up to 50,000 digests per Merkle audit submission in public SDK documentation.
Does the SDK support offline operation?
Yes. Offline-first queue with configurable auto-flush. Proofs generate locally when api.affix-io.com is unreachable and sync when connectivity returns.
From a source record to a verifiable decision
AffixIO is useful when another system needs to check a result without collecting the complete record behind it. Your service selects the source, evaluates the required condition and produces evidence for that particular check.
- Read the authorised source. Use a configured SQL lookup, HTTP JSON service or file export.
- Evaluate the condition. For a data-check workflow, compare the selected claim with the required value. Treat a source error separately from a negative decision.
- Choose the proof mode. UltraHonk proves the supported circuit relation. HMAC binds a local result under a different trust model.
- Verify and retain the evidence. Check the relevant proof or signature, then keep the policy and audit references needed by the receiving application.
Work through the external-source examples, compare proof modes, or use the full SDK reference.
Where the SDK fits
Use it in a service handling eligibility checks, an agent tool runner checking permission, or a merchant backend evaluating delegated checkout. The application must enforce the result before the controlled action.
Agent verification before payments explains the checks. User consent defines the authority behind them. The merchant guide shows where enforcement belongs.