OpenViSTAI · Agents · Blockchain · Crypto
Submit a project
Menu
Smart Contracts

Sismo Badges

Sismo Badges is an MIT-licensed repository of Sismo Protocol smart contracts: an attestations registry, an abstract contract for issuer logic, a non-transferable ERC-1155 badge view, and Hydra S1 zero-knowledge attester examples.

Explore the practical guide ↓

Independent OpenViST project profile, based on linked sources.

Sismo Badges — OpenViST project profile in Smart Contracts.
OpenViST project illustration. See the linked sources for product details.
Understand the project

Practical overview

When it fits

Use the repository when developing Sismo Protocol contract logic, especially an attester or a registry-backed badge system; consult its linked documentation for the broader protocol and attester guidance.

Who it is for

  • Solidity developers building or extending Sismo Protocol attesters.
  • Developers exploring registry-backed attestations and non-transferable badge views.
  • Teams prototyping proof-based attestation flows with Hydra S1 examples.

Documented uses

  • Implement request verification and construct attestations in a custom attester.
  • Use the registry and badge contracts as a pattern for recording and displaying attestations.
  • Study Hydra S1 attesters that accept zero-knowledge proofs and use nullifiers.
  • Install, compile, test, inspect storage layout, or deploy the contracts to a local chain.
Before you choose

Requirements & limits

The repository is public and specifies the MIT License.

  • Registry writes depend on issuer authorization by governance.
  • The Hydra S1 simple attester requires a zero-knowledge proof with the user request.
  • The account-bound Hydra S1 variant allows users to update where the attestation is stored.
  • The README documents local-chain deployment separately from its link to deployed contract addresses.

Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.

Source-based practical guide

Install and compile the contract repository

Prepare the repository dependencies and compile its contracts with the documented commands.

Before you start

  • A local development environment with Yarn available.

Steps

  1. Run yarn to install dependencies.

  2. Run yarn compile to compile the contracts using Hardhat.

Expected outcome

The repository dependencies are installed and the contracts are compiled.

Guide limitations

  • This covers setup and compilation only; it does not deploy contracts or verify a modified implementation.
Documentation 1 ↗
Source-based practical guide

Develop a custom attester

Add the required request-verification and attestation-construction logic to an attester inheriting the abstract contract.

Before you start

  • The repository and its core/Attester.sol abstract contract.
  • A design for validating requests against proof data and constructing attestations.

Steps

  1. Inherit core/Attester.sol in the new attester.

  2. Implement _verifyRequest(request, proofData) to verify the user request against its proof.

  3. Implement buildAttestations(request, proofData) to construct attestations from a verified request.

  4. Optionally implement _beforeRecordAttestations or _afterRecordAttestations hooks.

Expected outcome

A custom attester implementation with the required verification and attestation-construction functions.

Guide limitations

  • The repository describes the implementation responsibilities but does not establish that a particular custom attester is correct or compatible with a deployment.
Documentation 1 ↗
Evidence and transparency

Sources & review

Official repository ↗
Source record details
Source availability
Active
Sources checked
14 October 2026
Original website title
sismo-core/sismo-badges · Official homepage title · retained in its source language
How we review sourcesSuggest a correction