diff --git a/Tzkt.Api/Controllers/AccountsController.cs b/Tzkt.Api/Controllers/AccountsController.cs
index 93ca68b5f..2133e9949 100644
--- a/Tzkt.Api/Controllers/AccountsController.cs
+++ b/Tzkt.Api/Controllers/AccountsController.cs
@@ -147,7 +147,7 @@ public Task<int> GetCount(
         /// <param name="metadata">Include or not account metadata</param>
         /// <returns></returns>
         [HttpGet("{address}")]
-        public Task<Account> GetByAddress([Address] string address, bool metadata = false)
+        public Task<Account> GetByAddress([Required][Address] string address, bool metadata = false)
         {
             return Accounts.Get(address, metadata);
         }
@@ -165,7 +165,7 @@ public Task<Account> GetByAddress([Address] string address, bool metadata = fals
         /// <returns></returns>
         [HttpGet("{address}/contracts")]
         public async Task<ActionResult<IEnumerable<RelatedContract>>> GetContracts(
-            [Address] string address,
+            [Required][Address] string address,
             SortParameter sort,
             OffsetParameter offset,
             [Range(0, 10000)] int limit = 100)
@@ -194,7 +194,7 @@ public async Task<ActionResult<IEnumerable<RelatedContract>>> GetContracts(
         /// <returns></returns>
         [HttpGet("{address}/delegators")]
         public async Task<ActionResult<IEnumerable<Delegator>>> GetDelegators(
-            [Address] string address,
+            [Required][Address] string address,
             AccountTypeParameter type,
             Int64Parameter balance,
             Int32Parameter delegationLevel,
@@ -251,7 +251,7 @@ public async Task<ActionResult<IEnumerable<Delegator>>> GetDelegators(
         /// <returns></returns>
         [HttpGet("{address}/operations")]
         public async Task<ActionResult<IEnumerable<Operation>>> GetOperations(
-            [Address] string address,
+            [Required][Address] string address,
             string type,
             AccountParameter initiator,
             AccountParameter sender,
@@ -410,7 +410,7 @@ public async Task<ActionResult<IEnumerable<Operation>>> GetOperations(
         /// <param name="address">Account address (starting with tz or KT)</param>
         /// <returns></returns>
         [HttpGet("{address}/metadata")]
-        public Task<AccountMetadata> GetMetadata([Address] string address)
+        public Task<AccountMetadata> GetMetadata([Required][Address] string address)
         {
             return Accounts.GetMetadata(address);
         }
@@ -431,7 +431,7 @@ public Task<AccountMetadata> GetMetadata([Address] string address)
         /// <returns></returns>
         [HttpGet("{address}/report")]
         public async Task<ActionResult> GetBalanceReport(
-            [Address] string address,
+            [Required][Address] string address,
             DateTimeOffset? from,
             DateTimeOffset? to,
             string currency,
@@ -525,7 +525,7 @@ public async Task<ActionResult> GetBalanceReport(
         /// <returns></returns>
         [HttpGet("{address}/balance_history")]
         public async Task<ActionResult<IEnumerable<HistoricalBalance>>> GetBalanceHistory(
-            [Address] string address,
+            [Required][Address] string address,
             [Min(1)] int? step,
             SelectParameter select,
             SortParameter sort,
@@ -573,7 +573,7 @@ public async Task<ActionResult<IEnumerable<HistoricalBalance>>> GetBalanceHistor
         /// <param name="level">Block height at which you want to know account balance</param>
         /// <returns></returns>
         [HttpGet("{address}/balance_history/{level:int}")]
-        public Task<long> GetBalanceAtLevel([Address] string address, int level)
+        public Task<long> GetBalanceAtLevel([Required][Address] string address, [Min(0)] int level)
         {
             return History.Get(address, level);
         }
@@ -588,7 +588,7 @@ public Task<long> GetBalanceAtLevel([Address] string address, int level)
         /// <param name="datetime">Datetime at which you want to know account balance (e.g. `2020-01-01`, or `2019-12-30T23:42:59Z`)</param>
         /// <returns></returns>
         [HttpGet("{address}/balance_history/{datetime:DateTime}")]
-        public Task<long> GetBalanceAtDate([Address] string address, DateTimeOffset datetime)
+        public Task<long> GetBalanceAtDate([Required][Address] string address, DateTimeOffset datetime)
         {
             return History.Get(address, datetime.DateTime);
         }
diff --git a/Tzkt.Api/Controllers/BigMapsController.cs b/Tzkt.Api/Controllers/BigMapsController.cs
index 04fadb55d..eee26830d 100644
--- a/Tzkt.Api/Controllers/BigMapsController.cs
+++ b/Tzkt.Api/Controllers/BigMapsController.cs
@@ -246,7 +246,7 @@ public async Task<ActionResult<IEnumerable<BigMapKey>>> GetKeys(
         [HttpGet("{id:int}/keys/{key}")]
         public async Task<ActionResult<BigMapKey>> GetKey(
             [Min(0)] int id,
-            string key,
+            [Required] string key,
             MichelineFormat micheline = MichelineFormat.Json)
         {
             try
@@ -284,7 +284,7 @@ public async Task<ActionResult<BigMapKey>> GetKey(
         [HttpGet("{id:int}/keys/{key}/updates")]
         public async Task<ActionResult<IEnumerable<BigMapKeyUpdate>>> GetKeyUpdates(
             [Min(0)] int id,
-            string key,
+            [Required] string key,
             SortParameter sort,
             OffsetParameter offset,
             [Range(0, 10000)] int limit = 100,
@@ -391,7 +391,7 @@ public async Task<ActionResult<IEnumerable<BigMapKeyHistorical>>> GetHistoricalK
         public async Task<ActionResult<BigMapKeyHistorical>> GetKey(
             [Min(0)] int id,
             [Min(0)] int level,
-            string key,
+            [Required] string key,
             MichelineFormat micheline = MichelineFormat.Json)
         {
             try
diff --git a/Tzkt.Api/Controllers/BlocksController.cs b/Tzkt.Api/Controllers/BlocksController.cs
index 590176291..e87169f84 100644
--- a/Tzkt.Api/Controllers/BlocksController.cs
+++ b/Tzkt.Api/Controllers/BlocksController.cs
@@ -121,7 +121,7 @@ public async Task<ActionResult<IEnumerable<Block>>> Get(
         /// <returns></returns>
         [HttpGet("{hash}")]
         public Task<Block> GetByHash(
-            [BlockHash] string hash,
+            [Required][BlockHash] string hash,
             bool operations = false,
             MichelineFormat micheline = MichelineFormat.Json,
             Symbols quote = Symbols.None)
diff --git a/Tzkt.Api/Controllers/CommitmentsController.cs b/Tzkt.Api/Controllers/CommitmentsController.cs
index bc54028ba..657ec9989 100644
--- a/Tzkt.Api/Controllers/CommitmentsController.cs
+++ b/Tzkt.Api/Controllers/CommitmentsController.cs
@@ -31,7 +31,7 @@ public CommitmentsController(CommitmentRepository commitments, StateCache state)
         /// <param name="address">Blinded address (starting with btz)</param>
         /// <returns></returns>
         [HttpGet("{address}")]
-        public Task<Commitment> Get([BlindedAddress] string address)
+        public Task<Commitment> Get([Required][BlindedAddress] string address)
         {
             return Commitments.Get(address);
         }
diff --git a/Tzkt.Api/Controllers/ContractsController.cs b/Tzkt.Api/Controllers/ContractsController.cs
index 63e3ee2de..8d4b6a844 100644
--- a/Tzkt.Api/Controllers/ContractsController.cs
+++ b/Tzkt.Api/Controllers/ContractsController.cs
@@ -149,7 +149,7 @@ public Task<int> GetCount(ContractKindParameter kind)
         /// <param name="address">Contract address (starting with KT)</param>
         /// <returns></returns>
         [HttpGet("{address}")]
-        public Task<Contract> GetByAddress([Address] string address)
+        public Task<Contract> GetByAddress([Required][Address] string address)
         {
             return Accounts.GetContract(address);
         }
@@ -170,7 +170,7 @@ public Task<Contract> GetByAddress([Address] string address)
         /// <returns></returns>
         [HttpGet("{address}/same")]
         public async Task<ActionResult<IEnumerable<Contract>>> GetSame(
-            [Address] string address,
+            [Required][Address] string address,
             SelectParameter select,
             SortParameter sort,
             OffsetParameter offset,
@@ -229,7 +229,7 @@ public async Task<ActionResult<IEnumerable<Contract>>> GetSame(
         /// <returns></returns>
         [HttpGet("{address}/similar")]
         public async Task<ActionResult<IEnumerable<Contract>>> GetSimilar(
-            [Address] string address,
+            [Required][Address] string address,
             SelectParameter select,
             SortParameter sort,
             OffsetParameter offset,
@@ -282,7 +282,7 @@ public async Task<ActionResult<IEnumerable<Contract>>> GetSimilar(
         /// <param name="format">Code format (`0` - micheline, `1` - michelson, `2` - bytes (base64))</param>
         /// <returns></returns>
         [HttpGet("{address}/code")]
-        public async Task<object> GetCode([Address] string address, [Range(0, 2)] int format = 0)
+        public async Task<object> GetCode([Required][Address] string address, [Range(0, 2)] int format = 0)
         {
             if (format == 0)
                 return await Accounts.GetMichelineCode(address);
@@ -300,7 +300,7 @@ public async Task<object> GetCode([Address] string address, [Range(0, 2)] int fo
         /// <param name="address">Contract address</param>
         /// <returns></returns>
         [HttpGet("{address}/interface")]
-        public Task<ContractInterface> GetInterface([Address] string address)
+        public Task<ContractInterface> GetInterface([Required][Address] string address)
         {
             return Accounts.GetContractInterface(address);
         }
@@ -321,7 +321,7 @@ public Task<ContractInterface> GetInterface([Address] string address)
         /// <param name="michelson">Include parameters schema in michelson format</param>
         /// <returns></returns>
         [HttpGet("{address}/entrypoints")]
-        public Task<IEnumerable<Entrypoint>> GetEntrypoints([Address] string address, bool all = false, bool json = true, bool micheline = false, bool michelson = false)
+        public Task<IEnumerable<Entrypoint>> GetEntrypoints([Required][Address] string address, bool all = false, bool json = true, bool micheline = false, bool michelson = false)
         {
             return Accounts.GetEntrypoints(address, all, json, micheline, michelson);
         }
@@ -339,7 +339,7 @@ public Task<IEnumerable<Entrypoint>> GetEntrypoints([Address] string address, bo
         /// <param name="michelson">Include parameters schema in michelson format</param>
         /// <returns></returns>
         [HttpGet("{address}/entrypoints/{name}")]
-        public Task<Entrypoint> GetEntrypointByName([Address] string address, string name, bool json = true, bool micheline = false, bool michelson = false)
+        public Task<Entrypoint> GetEntrypointByName([Required][Address] string address, [Required] string name, bool json = true, bool micheline = false, bool michelson = false)
         {
             return Accounts.GetEntrypoint(address, name, json, micheline, michelson);
         }
@@ -355,7 +355,7 @@ public Task<Entrypoint> GetEntrypointByName([Address] string address, string nam
         /// <param name="value">Json parameters</param>
         /// <returns></returns>
         [HttpGet("{address}/entrypoints/{name}/build")]
-        public async Task<ActionResult> BuildEntrypointParameters([Address] string address, string name, string value)
+        public async Task<ActionResult> BuildEntrypointParameters([Required][Address] string address, [Required] string name, string value)
         {
             try
             {
@@ -379,7 +379,7 @@ public async Task<ActionResult> BuildEntrypointParameters([Address] string addre
         /// <param name="value">Json parameters</param>
         /// <returns></returns>
         [HttpPost("{address}/entrypoints/{name}/build")]
-        public async Task<ActionResult> BuildEntrypointParameters([Address] string address, string name, [FromBody] object value)
+        public async Task<ActionResult> BuildEntrypointParameters([Required][Address] string address, [Required] string name, [FromBody] object value)
         {
             try
             {
@@ -402,7 +402,7 @@ public async Task<ActionResult> BuildEntrypointParameters([Address] string addre
         /// <param name="path">Path in the JSON value (point-separated list of field names, e.g. `path=settings.refund_time` to return</param>
         /// <returns></returns>
         [HttpGet("{address}/storage")]
-        public async Task<ActionResult> GetStorage([Address] string address, [Min(0)] int level = 0, string path = null)
+        public async Task<ActionResult> GetStorage([Required][Address] string address, [Min(0)] int level = 0, string path = null)
         {
             #region safe path
             JsonPath[] jsonPath = null;
@@ -433,7 +433,7 @@ public async Task<ActionResult> GetStorage([Address] string address, [Min(0)] in
         /// <param name="level">Level at which storage schema should be taken. If `0` or not specified, the current schema will be returned.</param>
         /// <returns></returns>
         [HttpGet("{address}/storage/schema")]
-        public async Task<ActionResult> GetStorageSchema([Address] string address, [Min(0)] int level = 0)
+        public async Task<ActionResult> GetStorageSchema([Required][Address] string address, [Min(0)] int level = 0)
         {
             if (level == 0)
                 return this.Json(await Accounts.GetStorageSchema(address));
@@ -451,7 +451,7 @@ public async Task<ActionResult> GetStorageSchema([Address] string address, [Min(
         /// <param name="limit">Maximum number of items to return</param>
         /// <returns></returns>
         [HttpGet("{address}/storage/history")]
-        public Task<IEnumerable<StorageRecord>> GetStorageHistory([Address] string address, [Min(0)] int lastId = 0, [Range(0, 1000)] int limit = 10)
+        public Task<IEnumerable<StorageRecord>> GetStorageHistory([Required][Address] string address, [Min(0)] int lastId = 0, [Range(0, 1000)] int limit = 10)
         {
             return Accounts.GetStorageHistory(address, lastId, limit);
         }
@@ -466,7 +466,7 @@ public Task<IEnumerable<StorageRecord>> GetStorageHistory([Address] string addre
         /// <param name="level">Level at which storage value should be taken. If `0` or not specified, the current value will be returned.</param>
         /// <returns></returns>
         [HttpGet("{address}/storage/raw")]
-        public Task<IMicheline> GetRawStorage([Address] string address, [Min(0)] int level = 0)
+        public Task<IMicheline> GetRawStorage([Required][Address] string address, [Min(0)] int level = 0)
         {
             if (level == 0)
                 return Accounts.GetRawStorageValue(address);
@@ -483,7 +483,7 @@ public Task<IMicheline> GetRawStorage([Address] string address, [Min(0)] int lev
         /// <param name="level">Level at which storage schema should be taken. If `0` or not specified, the current schema will be returned.</param>
         /// <returns></returns>
         [HttpGet("{address}/storage/raw/schema")]
-        public Task<IMicheline> GetRawStorageSchema([Address] string address, [Min(0)] int level = 0)
+        public Task<IMicheline> GetRawStorageSchema([Required][Address] string address, [Min(0)] int level = 0)
         {
             if (level == 0)
                 return Accounts.GetRawStorageSchema(address);
@@ -501,7 +501,7 @@ public Task<IMicheline> GetRawStorageSchema([Address] string address, [Min(0)] i
         /// <param name="limit">Maximum number of items to return</param>
         /// <returns></returns>
         [HttpGet("{address}/storage/raw/history")]
-        public Task<IEnumerable<StorageRecord>> GetRawStorageHistory([Address] string address, [Min(0)] int lastId = 0, [Range(0, 1000)] int limit = 10)
+        public Task<IEnumerable<StorageRecord>> GetRawStorageHistory([Required][Address] string address, [Min(0)] int lastId = 0, [Range(0, 1000)] int limit = 10)
         {
             return Accounts.GetRawStorageHistory(address, lastId, limit);
         }
@@ -523,7 +523,7 @@ public Task<IEnumerable<StorageRecord>> GetRawStorageHistory([Address] string ad
         /// <returns></returns>
         [HttpGet("{address}/bigmaps")]
         public async Task<ActionResult<IEnumerable<BigMap>>> GetBigMaps(
-            [Address] string address,
+            [Required][Address] string address,
             BigMapTagsParameter tags,
             SelectParameter select,
             SortParameter sort,
@@ -581,8 +581,8 @@ public async Task<ActionResult<IEnumerable<BigMap>>> GetBigMaps(
         /// <returns></returns>
         [HttpGet("{address}/bigmaps/{name}")]
         public async Task<ActionResult<BigMap>> GetBigMapByName(
-            [Address] string address,
-            string name,
+            [Required][Address] string address,
+            [Required] string name,
             MichelineFormat micheline = MichelineFormat.Json)
         {
             var acc = await Accounts.GetRawAsync(address);
@@ -616,8 +616,8 @@ public async Task<ActionResult<BigMap>> GetBigMapByName(
         /// <returns></returns>
         [HttpGet("{address}/bigmaps/{name}/keys")]
         public async Task<ActionResult<IEnumerable<BigMapKey>>> GetBigMapByNameKeys(
-            [Address] string address,
-            string name,
+            [Required][Address] string address,
+            [Required] string name,
             bool? active,
             JsonParameter key,
             JsonParameter value,
@@ -682,9 +682,9 @@ public async Task<ActionResult<IEnumerable<BigMapKey>>> GetBigMapByNameKeys(
         /// <returns></returns>
         [HttpGet("{address}/bigmaps/{name}/keys/{key}")]
         public async Task<ActionResult<BigMapKey>> GetKey(
-            [Address] string address,
-            string name,
-            string key,
+            [Required][Address] string address,
+            [Required] string name,
+            [Required] string key,
             MichelineFormat micheline = MichelineFormat.Json)
         {
             var acc = await Accounts.GetRawAsync(address);
@@ -732,9 +732,9 @@ public async Task<ActionResult<BigMapKey>> GetKey(
         /// <returns></returns>
         [HttpGet("{address}/bigmaps/{name}/keys/{key}/updates")]
         public async Task<ActionResult<IEnumerable<BigMapKeyUpdate>>> GetKeyUpdates(
-            [Address] string address,
-            string name,
-            string key,
+            [Required][Address] string address,
+            [Required] string name,
+            [Required] string key,
             SortParameter sort,
             OffsetParameter offset,
             [Range(0, 10000)] int limit = 100,
@@ -795,8 +795,8 @@ public async Task<ActionResult<IEnumerable<BigMapKeyUpdate>>> GetKeyUpdates(
         /// <returns></returns>
         [HttpGet("{address}/bigmaps/{name}/historical_keys/{level:int}")]
         public async Task<ActionResult<IEnumerable<BigMapKeyHistorical>>> GetHistoricalKeys(
-            [Address] string address,
-            string name,
+            [Required][Address] string address,
+            [Required] string name,
             [Min(0)] int level,
             bool? active,
             JsonParameter key,
@@ -862,10 +862,10 @@ public async Task<ActionResult<IEnumerable<BigMapKeyHistorical>>> GetHistoricalK
         /// <returns></returns>
         [HttpGet("{address}/bigmaps/{name}/historical_keys/{level:int}/{key}")]
         public async Task<ActionResult<BigMapKeyHistorical>> GetKey(
-            [Address] string address,
-            string name,
+            [Required][Address] string address,
+            [Required] string name,
             [Min(0)] int level,
-            string key,
+            [Required] string key,
             MichelineFormat micheline = MichelineFormat.Json)
         {
             var acc = await Accounts.GetRawAsync(address);
diff --git a/Tzkt.Api/Controllers/CyclesController.cs b/Tzkt.Api/Controllers/CyclesController.cs
index 070a03d64..8c3051f27 100644
--- a/Tzkt.Api/Controllers/CyclesController.cs
+++ b/Tzkt.Api/Controllers/CyclesController.cs
@@ -99,7 +99,7 @@ public async Task<ActionResult<IEnumerable<Cycle>>> Get(
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("{index:int}")]
-        public Task<Cycle> GetByIndex(int index, Symbols quote = Symbols.None)
+        public Task<Cycle> GetByIndex([Min(0)] int index, Symbols quote = Symbols.None)
         {
             return Cycles.Get(index, quote);
         }
diff --git a/Tzkt.Api/Controllers/DelegatesController.cs b/Tzkt.Api/Controllers/DelegatesController.cs
index 5daa7ec8c..82d91205c 100644
--- a/Tzkt.Api/Controllers/DelegatesController.cs
+++ b/Tzkt.Api/Controllers/DelegatesController.cs
@@ -95,7 +95,7 @@ public Task<int> GetCount(BoolParameter active)
         /// <param name="address">Delegate address (starting with tz)</param>
         /// <returns></returns>
         [HttpGet("{address}")]
-        public Task<Models.Delegate> GetByAddress([Address] string address)
+        public Task<Models.Delegate> GetByAddress([Required][Address] string address)
         {
             return Accounts.GetDelegate(address);
         }
diff --git a/Tzkt.Api/Controllers/OperationsController.cs b/Tzkt.Api/Controllers/OperationsController.cs
index d01303046..eff197ee6 100644
--- a/Tzkt.Api/Controllers/OperationsController.cs
+++ b/Tzkt.Api/Controllers/OperationsController.cs
@@ -37,7 +37,7 @@ public OperationsController(OperationRepository operations, StateCache state)
         /// <returns></returns>
         [HttpGet("{hash}")]
         public Task<IEnumerable<Operation>> GetByHash(
-            [OpHash] string hash,
+            [Required][OpHash] string hash,
             MichelineFormat micheline = MichelineFormat.Json,
             Symbols quote = Symbols.None)
         {
@@ -57,7 +57,7 @@ public Task<IEnumerable<Operation>> GetByHash(
         /// <returns></returns>
         [HttpGet("{hash}/{counter}")]
         public Task<IEnumerable<Operation>> GetByHashCounter(
-            [OpHash] string hash,
+            [Required][OpHash] string hash,
             [Min(0)] int counter,
             MichelineFormat micheline = MichelineFormat.Json,
             Symbols quote = Symbols.None)
@@ -79,7 +79,7 @@ public Task<IEnumerable<Operation>> GetByHashCounter(
         /// <returns></returns>
         [HttpGet("{hash}/{counter}/{nonce}")]
         public Task<IEnumerable<Operation>> GetByHashCounterNonce(
-            [OpHash] string hash,
+            [Required][OpHash] string hash,
             [Min(0)] int counter,
             [Min(0)] int nonce,
             MichelineFormat micheline = MichelineFormat.Json,
@@ -168,7 +168,7 @@ public async Task<ActionResult<IEnumerable<EndorsementOperation>>> GetEndorsemen
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("endorsements/{hash}")]
-        public Task<IEnumerable<EndorsementOperation>> GetEndorsementByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<EndorsementOperation>> GetEndorsementByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetEndorsements(hash, quote);
         }
@@ -279,7 +279,7 @@ public async Task<ActionResult<IEnumerable<BallotOperation>>> GetBallots(
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("ballots/{hash}")]
-        public Task<IEnumerable<BallotOperation>> GetBallotByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<BallotOperation>> GetBallotByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetBallots(hash, quote);
         }
@@ -392,7 +392,7 @@ public async Task<ActionResult<IEnumerable<ProposalOperation>>> GetProposals(
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("proposals/{hash}")]
-        public Task<IEnumerable<ProposalOperation>> GetProposalByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<ProposalOperation>> GetProposalByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetProposals(hash, quote);
         }
@@ -497,7 +497,7 @@ public async Task<ActionResult<IEnumerable<ActivationOperation>>> GetActivations
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("activations/{hash}")]
-        public Task<IEnumerable<ActivationOperation>> GetActivationByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<ActivationOperation>> GetActivationByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetActivations(hash, quote);
         }
@@ -627,7 +627,7 @@ public async Task<ActionResult<IEnumerable<DoubleBakingOperation>>> GetDoubleBak
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("double_baking/{hash}")]
-        public Task<IEnumerable<DoubleBakingOperation>> GetDoubleBakingByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<DoubleBakingOperation>> GetDoubleBakingByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetDoubleBakings(hash, quote);
         }
@@ -757,7 +757,7 @@ public async Task<ActionResult<IEnumerable<DoubleEndorsingOperation>>> GetDouble
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("double_endorsing/{hash}")]
-        public Task<IEnumerable<DoubleEndorsingOperation>> GetDoubleEndorsingByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<DoubleEndorsingOperation>> GetDoubleEndorsingByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetDoubleEndorsings(hash, quote);
         }
@@ -887,7 +887,7 @@ public async Task<ActionResult<IEnumerable<NonceRevelationOperation>>> GetNonceR
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("nonce_revelations/{hash}")]
-        public Task<IEnumerable<NonceRevelationOperation>> GetNonceRevelationByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<NonceRevelationOperation>> GetNonceRevelationByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetNonceRevelations(hash, quote);
         }
@@ -1047,7 +1047,7 @@ public async Task<ActionResult<IEnumerable<DelegationOperation>>> GetDelegations
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("delegations/{hash}")]
-        public Task<IEnumerable<DelegationOperation>> GetDelegationByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<DelegationOperation>> GetDelegationByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetDelegations(hash, quote);
         }
@@ -1229,7 +1229,7 @@ public async Task<ActionResult<IEnumerable<OriginationOperation>>> GetOriginatio
         /// <returns></returns>
         [HttpGet("originations/{hash}")]
         public Task<IEnumerable<OriginationOperation>> GetOriginationByHash(
-            [OpHash] string hash,
+            [Required][OpHash] string hash,
             MichelineFormat micheline,
             Symbols quote = Symbols.None)
         {
@@ -1392,7 +1392,7 @@ public async Task<ActionResult<IEnumerable<TransactionOperation>>> GetTransactio
         /// <returns></returns>
         [HttpGet("transactions/{hash}")]
         public Task<IEnumerable<TransactionOperation>> GetTransactionByHash(
-            [OpHash] string hash,
+            [Required][OpHash] string hash,
             MichelineFormat micheline = MichelineFormat.Json,
             Symbols quote = Symbols.None)
         {
@@ -1412,7 +1412,7 @@ public Task<IEnumerable<TransactionOperation>> GetTransactionByHash(
         /// <returns></returns>
         [HttpGet("transactions/{hash}/{counter}")]
         public Task<IEnumerable<TransactionOperation>> GetTransactionByHashCounter(
-            [OpHash] string hash,
+            [Required][OpHash] string hash,
             [Min(0)] int counter,
             MichelineFormat micheline = MichelineFormat.Json,
             Symbols quote = Symbols.None)
@@ -1434,7 +1434,7 @@ public Task<IEnumerable<TransactionOperation>> GetTransactionByHashCounter(
         /// <returns></returns>
         [HttpGet("transactions/{hash}/{counter}/{nonce}")]
         public Task<IEnumerable<TransactionOperation>> GetTransactionByHashCounterNonce(
-            [OpHash] string hash,
+            [Required][OpHash] string hash,
             [Min(0)] int counter,
             [Min(0)] int nonce,
             MichelineFormat micheline = MichelineFormat.Json,
@@ -1547,7 +1547,7 @@ public async Task<ActionResult<IEnumerable<RevealOperation>>> GetReveals(
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("reveals/{hash}")]
-        public Task<IEnumerable<RevealOperation>> GetRevealByHash([OpHash] string hash, Symbols quote = Symbols.None)
+        public Task<IEnumerable<RevealOperation>> GetRevealByHash([Required][OpHash] string hash, Symbols quote = Symbols.None)
         {
             return Operations.GetReveals(hash, quote);
         }
diff --git a/Tzkt.Api/Controllers/ProtocolsController.cs b/Tzkt.Api/Controllers/ProtocolsController.cs
index 3f1b0c527..c9062e1f1 100644
--- a/Tzkt.Api/Controllers/ProtocolsController.cs
+++ b/Tzkt.Api/Controllers/ProtocolsController.cs
@@ -96,7 +96,7 @@ public Task<Protocol> GetByCode([Min(0)] int code)
         /// <param name="hash">Protocol hash</param>
         /// <returns></returns>
         [HttpGet("{hash}")]
-        public Task<Protocol> GetByHash([ProtocolHash] string hash)
+        public Task<Protocol> GetByHash([Required][ProtocolHash] string hash)
         {
             return Protocols.Get(hash);
         }
diff --git a/Tzkt.Api/Controllers/RewardsController.cs b/Tzkt.Api/Controllers/RewardsController.cs
index af15592d0..1c7d829ed 100644
--- a/Tzkt.Api/Controllers/RewardsController.cs
+++ b/Tzkt.Api/Controllers/RewardsController.cs
@@ -30,7 +30,7 @@ public RewardsController(RewardsRepository rewards)
         /// <param name="address">Baker address</param>
         /// <returns></returns>
         [HttpGet("bakers/{address}/count")]
-        public Task<int> GetBakerRewardsCount([Address] string address)
+        public Task<int> GetBakerRewardsCount([Required][Address] string address)
         {
             return Rewards.GetBakerRewardsCount(address);
         }
@@ -51,7 +51,7 @@ public Task<int> GetBakerRewardsCount([Address] string address)
         /// <returns></returns>
         [HttpGet("bakers/{address}")]
         public async Task<ActionResult<IEnumerable<BakerRewards>>> GetBakerRewards(
-            [Address] string address,
+            [Required][Address] string address,
             Int32Parameter cycle,
             SelectParameter select,
             SortParameter sort,
@@ -100,7 +100,7 @@ public async Task<ActionResult<IEnumerable<BakerRewards>>> GetBakerRewards(
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("bakers/{address}/{cycle:int}")]
-        public Task<BakerRewards> GetBakerRewardsByCycle([Address] string address, int cycle, Symbols quote = Symbols.None)
+        public Task<BakerRewards> GetBakerRewardsByCycle([Required][Address] string address, [Min(0)] int cycle, Symbols quote = Symbols.None)
         {
             return Rewards.GetBakerRewards(address, cycle, quote);
         }
@@ -114,7 +114,7 @@ public Task<BakerRewards> GetBakerRewardsByCycle([Address] string address, int c
         /// <param name="address">Delegator address</param>
         /// <returns></returns>
         [HttpGet("delegators/{address}/count")]
-        public Task<int> GetDelegatorRewardsCount([Address] string address)
+        public Task<int> GetDelegatorRewardsCount([Required][Address] string address)
         {
             return Rewards.GetDelegatorRewardsCount(address);
         }
@@ -135,7 +135,7 @@ public Task<int> GetDelegatorRewardsCount([Address] string address)
         /// <returns></returns>
         [HttpGet("delegators/{address}")]
         public async Task<ActionResult<IEnumerable<DelegatorRewards>>> GetDelegatorRewards(
-            [Address] string address,
+            [Required][Address] string address,
             Int32Parameter cycle,
             SelectParameter select,
             SortParameter sort,
@@ -184,7 +184,7 @@ public async Task<ActionResult<IEnumerable<DelegatorRewards>>> GetDelegatorRewar
         /// <param name="quote">Comma-separated list of ticker symbols to inject historical prices into response</param>
         /// <returns></returns>
         [HttpGet("delegators/{address}/{cycle:int}")]
-        public Task<DelegatorRewards> GetDelegatorRewardsByCycle([Address] string address, int cycle, Symbols quote = Symbols.None)
+        public Task<DelegatorRewards> GetDelegatorRewardsByCycle([Required][Address] string address, [Min(0)] int cycle, Symbols quote = Symbols.None)
         {
             return Rewards.GetDelegatorRewards(address, cycle, quote);
         }
@@ -201,7 +201,7 @@ public Task<DelegatorRewards> GetDelegatorRewardsByCycle([Address] string addres
         /// <param name="limit">Maximum number of delegators to return</param>
         /// <returns></returns>
         [HttpGet("split/{address}/{cycle:int}")]
-        public Task<RewardSplit> GetRewardSplit([Address] string address, int cycle, int offset = 0, [Range(0, 10000)] int limit = 100)
+        public Task<RewardSplit> GetRewardSplit([Required][Address] string address, [Min(0)] int cycle, int offset = 0, [Range(0, 10000)] int limit = 100)
         {
             return Rewards.GetRewardSplit(address, cycle, offset, limit);
         }
@@ -217,7 +217,7 @@ public Task<RewardSplit> GetRewardSplit([Address] string address, int cycle, int
         /// <param name="delegator">Delegator address</param>
         /// <returns></returns>
         [HttpGet("split/{baker}/{cycle:int}/{delegator}")]
-        public Task<SplitDelegator> GetRewardSplitDelegator([Address] string baker, int cycle, [Address] string delegator)
+        public Task<SplitDelegator> GetRewardSplitDelegator([Required][Address] string baker, [Min(0)] int cycle, [Required][Address] string delegator)
         {
             return Rewards.GetRewardSplitDelegator(baker, cycle, delegator);
         }
diff --git a/Tzkt.Api/Controllers/RightsController.cs b/Tzkt.Api/Controllers/RightsController.cs
index dc20ace93..559a9d063 100644
--- a/Tzkt.Api/Controllers/RightsController.cs
+++ b/Tzkt.Api/Controllers/RightsController.cs
@@ -113,7 +113,7 @@ public async Task<ActionResult<IEnumerable<BakingRight>>> Get(
         [OpenApiIgnore]
         [HttpGet("schedule")]
         public async Task<ActionResult<IEnumerable<BakingRight>>> GetSchedule(
-            [Address] [Required] string baker,
+            [Required][Address] string baker,
             [Required] DateTimeOffset from,
             [Required] DateTimeOffset to,
             [Min(0)] int maxPriority = 0)
diff --git a/Tzkt.Api/Controllers/VotingController.cs b/Tzkt.Api/Controllers/VotingController.cs
index 6a2d28b39..dbfab6caa 100644
--- a/Tzkt.Api/Controllers/VotingController.cs
+++ b/Tzkt.Api/Controllers/VotingController.cs
@@ -97,7 +97,7 @@ public async Task<ActionResult<IEnumerable<Proposal>>> GetProposals(
         /// <param name="hash">Proposal hash</param>
         /// <returns></returns>
         [HttpGet("proposals/{hash}")]
-        public Task<Proposal> GetProposalByHash([ProtocolHash] string hash)
+        public Task<Proposal> GetProposalByHash([Required][ProtocolHash] string hash)
         {
             return Voting.GetProposal(hash);
         }
@@ -217,7 +217,7 @@ public async Task<ActionResult<IEnumerable<VoterSnapshot>>> GetPeriodVoters(
         /// <param name="address">Voter address</param>
         /// <returns></returns>
         [HttpGet("periods/{index:int}/voters/{address}")]
-        public Task<VoterSnapshot> GetPeriodVoter([Min(0)] int index, [Address] string address)
+        public Task<VoterSnapshot> GetPeriodVoter([Min(0)] int index, [Required][Address] string address)
         {
             return Voting.GetVoter(index, address);
         }
@@ -257,7 +257,7 @@ public async Task<ActionResult<IEnumerable<VoterSnapshot>>> GetPeriodVoters(
         /// <param name="address">Voter address</param>
         /// <returns></returns>
         [HttpGet("periods/current/voters/{address}")]
-        public Task<VoterSnapshot> GetPeriodVoter([Address] string address)
+        public Task<VoterSnapshot> GetPeriodVoter([Required][Address] string address)
         {
             return Voting.GetVoter(State.Current.VotingPeriod, address);
         }