feat: Implement a comprehensive, standards-compliant NFT contract

.github/workflows/nftopia-backend.yml

@@ -110,7 +110,7 @@ jobs:
 
     - name: Upload build artifact
       if: success() && github.event_name == 'push' && github.ref == 'refs/heads/main'
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: nftopia-backend-dist
         path: nftopia-backend/dist/

.github/workflows/nftopia-frontend.yml

@@ -68,7 +68,7 @@ jobs:
 
     - name: Upload build artifact
       if: success() && github.event_name == 'push' && github.ref == 'refs/heads/main'
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: nftopia-frontend-build
         path: nftopia-frontend/.next/

.github/workflows/nftopia-stellar.yml

@@ -63,7 +63,7 @@ jobs:
 
     - name: Upload contract artifact
       if: success() && github.event_name == 'push' && github.ref == 'refs/heads/main'
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: nftopia-stellar-contract
         path: nftopia-stellar/target/wasm32-unknown-unknown/release/*.wasm

.turbo/daemon/964d605253d87a62-turbo.log.2026-01-29

@@ -0,0 +1,18 @@
+2026-01-29T03:38:10.501310Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".turbo/cookies/1.cookie"), AnchoredSystemPathBuf(".turbo/cookies/.turbo-cookie")}
+2026-01-29T03:38:10.501332Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))
+2026-01-29T03:38:10.600644Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".turbo/cache")}
+2026-01-29T03:38:10.600654Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))
+2026-01-29T03:40:36.303858Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".turbo/cookies/2.cookie")}
+2026-01-29T03:40:36.304546Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))
+2026-01-29T03:40:54.801182Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".turbo/cookies/3.cookie")}
+2026-01-29T03:40:54.801191Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))
+2026-01-29T03:41:23.000662Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".turbo/cookies/4.cookie")}
+2026-01-29T03:41:23.000672Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))
+2026-01-29T03:42:21.604995Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".turbo/cookies/5.cookie")}
+2026-01-29T03:42:21.605006Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))
+2026-01-29T03:45:26.500260Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".github/workflows/nftopia-stellar.yml")}
+2026-01-29T03:45:26.500293Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))
+2026-01-29T03:45:36.700367Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".github/workflows/nftopia-frontend.yml")}
+2026-01-29T03:45:36.700380Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))
+2026-01-29T03:45:41.406663Z  WARN turborepo_lib::package_changes_watcher: changed_files: {AnchoredSystemPathBuf(".github/workflows/nftopia-backend.yml")}
+2026-01-29T03:45:41.406680Z  WARN turborepo_lib::package_changes_watcher: changed_packages: Ok(Some({WorkspacePackage { name: Root, path: AnchoredSystemPathBuf("") }}))

nftopia-stellar/contracts/nft_contract/Cargo.toml

@@ -4,3 +4,11 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+soroban-sdk = { workspace = true }
+
+[dev-dependencies]
+soroban-sdk = { workspace = true, features = ["testutils"] }
+
+[lib]
+crate-type = ["cdylib"]
+path = "src/lib.rs"

nftopia-stellar/contracts/nft_contract/src/access_control.rs

@@ -0,0 +1,54 @@
+use soroban_sdk::{contracttype, Address, Env};
+
+use crate::error::ContractError;
+use crate::storage::{get_owner, has_role_entry, set_role_entry};
+
+#[contracttype]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum Role {
+    Owner,
+    Admin,
+    Minter,
+    Burner,
+    MetadataUpdater,
+}
+
+pub fn set_role(env: &Env, role: Role, addr: Address, enabled: bool) {
+    set_role_entry(env, role, &addr, enabled);
+}
+
+pub fn has_role(env: &Env, role: Role, addr: &Address) -> bool {
+    if role == Role::Owner {
+        if let Ok(owner) = get_owner(env) {
+            return &owner == addr;
+        }
+        return false;
+    }
+
+    if let Ok(owner) = get_owner(env) {
+        if &owner == addr {
+            return true;
+        }
+    }
+
+    has_role_entry(env, role, addr)
+}
+
+pub fn require_role(env: &Env, role: Role) -> Result<(), ContractError> {
+    let invoker = env.invoker();
+    invoker.require_auth();
+    if !has_role(env, role, &invoker) {
+        return Err(ContractError::Unauthorized);
+    }
+    Ok(())
+}
+
+pub fn require_owner(env: &Env) -> Result<(), ContractError> {
+    let invoker = env.invoker();
+    invoker.require_auth();
+    let owner = get_owner(env)?;
+    if invoker != owner {
+        return Err(ContractError::Unauthorized);
+    }
+    Ok(())
+}

nftopia-stellar/contracts/nft_contract/src/error.rs

@@ -0,0 +1,22 @@
+use soroban_sdk::contracterror;
+
+#[contracterror]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum ContractError {
+    AlreadyInitialized = 1,
+    NotInitialized = 2,
+    Unauthorized = 3,
+    TokenNotFound = 4,
+    InvalidBatchLength = 5,
+    MaxSupplyReached = 6,
+    MetadataFrozen = 7,
+    BurnNotConfirmed = 8,
+    TransfersPaused = 9,
+    MintingPaused = 10,
+    ContractPaused = 11,
+    InvalidRoyaltyPercentage = 12,
+    RevealNotReady = 13,
+    InvalidSalePrice = 14,
+    NotWhitelisted = 15,
+    ReentrancyDetected = 16,
+}

nftopia-stellar/contracts/nft_contract/src/events.rs

@@ -0,0 +1,52 @@
+use soroban_sdk::{Address, Env, String, Symbol};
+
+use crate::access_control::Role;
+
+pub fn emit_transfer(env: &Env, from: Address, to: Address, token_id: u64) {
+    env.events()
+        .publish((Symbol::new(env, "transfer"),), (from, to, token_id));
+}
+
+pub fn emit_mint(env: &Env, to: Address, token_id: u64) {
+    env.events()
+        .publish((Symbol::new(env, "mint"),), (to, token_id));
+}
+
+pub fn emit_burn(env: &Env, owner: Address, token_id: u64) {
+    env.events()
+        .publish((Symbol::new(env, "burn"),), (owner, token_id));
+}
+
+pub fn emit_approval(env: &Env, approved: Address, token_id: u64) {
+    env.events()
+        .publish((Symbol::new(env, "approval"),), (approved, token_id));
+}
+
+pub fn emit_approval_for_all(env: &Env, owner: Address, operator: Address, approved: bool) {
+    env.events()
+        .publish((Symbol::new(env, "approval_for_all"),), (owner, operator, approved));
+}
+
+pub fn emit_metadata_update(env: &Env, token_id: u64) {
+    env.events()
+        .publish((Symbol::new(env, "metadata_update"),), token_id);
+}
+
+pub fn emit_base_uri_update(env: &Env, uri: String) {
+    env.events()
+        .publish((Symbol::new(env, "base_uri_update"),), uri);
+}
+
+pub fn emit_pause(env: &Env, paused: bool) {
+    env.events().publish((Symbol::new(env, "pause"),), paused);
+}
+
+pub fn emit_role_grant(env: &Env, role: Role, to: Address) {
+    env.events()
+        .publish((Symbol::new(env, "role_grant"),), (role, to));
+}
+
+pub fn emit_role_revoke(env: &Env, role: Role, from: Address) {
+    env.events()
+        .publish((Symbol::new(env, "role_revoke"),), (role, from));
+}

nftopia-stellar/contracts/nft_contract/src/interface.rs

@@ -0,0 +1,10 @@
+use soroban_sdk::{Env, Symbol};
+
+pub fn supports_interface_id(env: &Env, interface_id: Symbol) -> bool {
+    let nft = Symbol::new(env, "nft");
+    let metadata = Symbol::new(env, "metadata");
+    let royalty = Symbol::new(env, "royalty");
+    let access = Symbol::new(env, "access_control");
+
+    interface_id == nft || interface_id == metadata || interface_id == royalty || interface_id == access
+}