# Smart Contract Reference The Stobox DID smart contract forms the on-chain identity layer for compliant tokenized asset operations. It manages decentralized identities (DIDs), linked wallets, identity attributes, and role-based permissions. *** ### **Contract Architecture Overview** The DID contract includes the following components: * **DID Registry** — stores and manages identity state. * **Attribute Storage** — holds compliance attributes and metadata. * **Address Linking Module** — associates user wallets with DIDs. * **Role-Based Access Control** — defines who may perform administrative or read operations. * **Event Layer** — logs all operations for full auditability. These components form a unified identity system that STV3 assets query during compliance validation. *** ### **Data Structures** #### **DID Record** Each DID includes: * unique DID identifier * status (active, blocked, revoked) * linked addresses * attributes list #### **Attribute Structure** Attributes include: * attribute key (identifier) * attribute value * timestamp * expiration date (optional) * active/inactive status * issuer (administrator) #### **Address Record** For each address: * linked DID * activation status * timestamp * reference to issuer or admin role These structures ensure precise, auditable identity tracking. *** ### **Roles & Permissions** The DID contract uses RBAC (Role-Based Access Control) with several key roles. #### **ADMIN ROLE** Full control over: * DID creation, blocking, revocation * attribute assignment and modification * wallet linking/unlinking * contract configuration * assigning other roles #### **WRITER ROLE** Allowed to: * assign or update identity attributes * link or unlink wallet addresses * activate or deactivate wallets #### **READER ROLE** Allowed to: * view DID status * query attributes * check wallet linkage #### **EXTERNAL READER ROLE** Time-limited permission for: * auditors * regulators * partners requiring controlled access This role expires automatically after a defined period. *** ### **Core Functions** The following functions represent the most important developer-facing methods in the DID contract. *** #### **DID Management** **`createDID(address wallet)`** Creates a new DID and links the provided wallet. **`blockDID(did)`** Disables all access for the DID and linked addresses. **`unblockDID(did)`** Reactivates a previously blocked DID. **`revokeDID(did)`** Permanently invalidates a DID, disabling all wallets. *** #### **Wallet & Address Management** **`linkAddressToDID(address wallet, did)`** Associates a new wallet with an existing DID. **`removeLinkedAddress(address wallet)`** Unlinks a wallet from a DID. **`activateAddress(address wallet)`** Re-enables a previously deactivated wallet. **`deactivateAddress(address wallet)`** Temporarily suspends a wallet. *** #### **Attribute Management** **`addOrUpdateAttribute(did, key, value, expiration)`** Assigns or updates an identity attribute. **`deactivateAttribute(did, key)`** Marks an attribute as inactive without deleting it. **`updateAttributeExpiration(did, key, newExpiration)`** Updates the validity period of an attribute. *** #### **Query Functions** These functions allow external contracts (e.g., STV3 tokens) to verify compliance. **`getDID(address wallet)`** Returns the DID associated with a wallet. **`getAttributes(did)`** Returns all attributes for the DID. **`hasActiveAttribute(did, key)`** Checks if the DID has an active attribute. **`isAddressActive(wallet)`** Checks if the wallet is active. **`getDIDStatus(did)`** Returns DID status (active/blocked/revoked). *** ### **Events & Audit Logging** Events provide a transparent and immutable audit trail for compliance and identity operations. Key events include: * `DIDCreated` * `DIDUpdated` * `DIDBlocked` * `DIDUnblocked` * `DIDRevoked` * `AddressLinked` * `AddressActivated` * `AddressDeactivated` * `AddressRemoved` * `AttributeAssigned` * `AttributeUpdated` * `AttributeRevoked` Auditors and compliance systems use these event logs to reconstruct identity history. *** ### **Integration Notes for Developers** #### **Compliance Modules Must Query DID** Assets using STV3 validation must call DID query functions to: * verify identity status * check attributes * validate wallet linkage * enforce rules based on DID data #### **Multiple Contracts Can Read DID State** DID is designed as a global identity registry across: * token contracts * marketplaces * custody systems * corporate governance tools * exchanges #### **Use Events for Off-Chain Compliance Tools** External services (KYC providers, admins, auditors) can subscribe to DID events to track updates. #### **Access Control Must Be Respected** Only administrator roles should manage DID states to avoid compliance breaches. *** ### **Error Handling and Edge Cases** Developers should consider: * expired attributes * deactivated wallet addresses * blocked DID states * revoked DIDs * invalid attribute combinations * attributes that must be present for an action A DID failure should result in the calling contract rejecting the transaction. *** ### **Summary** The Stobox DID smart contract provides a complete, on-chain identity and compliance framework. Its clearly defined functions, roles, data structures, and events enable: * deterministic compliance * auditable identity management * secure source-of-truth identity logic * enterprise-level permission control * seamless integration with programmable assets This reference chapter enables developers and integrators to confidently build applications that depend on DID for identity validation and regulated workflows. *** --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.stobox.io/did/smart-contract-reference.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. 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