diff --git a/src/GameCult.Networking/Contracts/cultnet.document-mutation-contract.schema.json b/src/GameCult.Networking/Contracts/cultnet.document-mutation-contract.schema.json
new file mode 100644
index 00000000..e444fef0
--- /dev/null
+++ b/src/GameCult.Networking/Contracts/cultnet.document-mutation-contract.schema.json
@@ -0,0 +1,40 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://github.com/GameCult/cultnet-ts/contracts/cultnet.document-mutation-contract.schema.json",
+  "title": "CultNet Document Mutation Contract",
+  "type": "object",
+  "required": [
+    "documentType",
+    "operations",
+    "authority"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "documentType": { "type": "string", "minLength": 1 },
+    "payloadSchemaVersion": { "type": "string", "minLength": 1 },
+    "operations": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "string",
+        "enum": ["snapshot", "documentPut", "documentDelete", "intentSubmit", "receiptWatch"]
+      }
+    },
+    "authority": {
+      "type": "string",
+      "enum": ["readOnly", "localUser", "coordinator", "runtime", "denied"]
+    },
+    "intentDocumentTypes": {
+      "type": "array",
+      "items": { "type": "string", "minLength": 1 }
+    },
+    "receiptDocumentTypes": {
+      "type": "array",
+      "items": { "type": "string", "minLength": 1 }
+    },
+    "notes": {
+      "type": "array",
+      "items": { "type": "string", "minLength": 1 }
+    }
+  }
+}
diff --git a/src/GameCult.Networking/Contracts/cultnet.hello.schema.json b/src/GameCult.Networking/Contracts/cultnet.hello.schema.json
index f15f7452..bced7577 100644
--- a/src/GameCult.Networking/Contracts/cultnet.hello.schema.json
+++ b/src/GameCult.Networking/Contracts/cultnet.hello.schema.json
@@ -20,6 +20,12 @@
       "type": "array",
       "items": { "type": "string", "minLength": 1 }
     },
+    "supportedMutationContracts": {
+      "type": "array",
+      "items": {
+        "$ref": "./cultnet.document-mutation-contract.schema.json"
+      }
+    },
     "supportedMessageVersions": {
       "type": "array",
       "items": { "type": "string", "minLength": 1 }
diff --git a/src/GameCult.Networking/CultNetSchemaMessages.cs b/src/GameCult.Networking/CultNetSchemaMessages.cs
index 69ff8694..5281fb79 100644
--- a/src/GameCult.Networking/CultNetSchemaMessages.cs
+++ b/src/GameCult.Networking/CultNetSchemaMessages.cs
@@ -81,6 +81,69 @@ namespace GameCult.Networking
         public const string SchemaCatalogResponse = "cultnet.schema_catalog_response.v0";
     }
 
+    /// <summary>
+    /// Mutation authority owner identifiers advertised through CultNet mutation contracts.
+    /// </summary>
+    public static class CultNetMutationAuthorities
+    {
+        /// <summary>
+        /// The document is inspectable but not writable through CultNet.
+        /// </summary>
+        public const string ReadOnly = "readOnly";
+        /// <summary>
+        /// The local human operator may submit the corresponding mutation intent.
+        /// </summary>
+        public const string LocalUser = "localUser";
+        /// <summary>
+        /// A coordinator-owned Epiphany control surface owns the mutation path.
+        /// </summary>
+        public const string Coordinator = "coordinator";
+        /// <summary>
+        /// The runtime itself may write this document directly.
+        /// </summary>
+        public const string Runtime = "runtime";
+        /// <summary>
+        /// The document should not be mutated through CultNet.
+        /// </summary>
+        public const string Denied = "denied";
+    }
+
+    /// <summary>
+    /// Declares how a document or surface may be inspected and mutated over CultNet.
+    /// </summary>
+    [MessagePackObject]
+    public class CultNetDocumentMutationContract
+    {
+        /// <summary>
+        /// Gets or sets the stable document type governed by this contract.
+        /// </summary>
+        [Key("documentType")] public string DocumentType { get; set; } = string.Empty;
+        /// <summary>
+        /// Gets or sets the payload schema version when the contract governs a versioned document payload.
+        /// </summary>
+        [Key("payloadSchemaVersion")] public string? PayloadSchemaVersion { get; set; }
+        /// <summary>
+        /// Gets or sets the CultNet operations this document accepts.
+        /// </summary>
+        [Key("operations")] public string[] Operations { get; set; } = Array.Empty<string>();
+        /// <summary>
+        /// Gets or sets which actor is allowed to drive those operations.
+        /// </summary>
+        [Key("authority")] public string Authority { get; set; } = CultNetMutationAuthorities.ReadOnly;
+        /// <summary>
+        /// Gets or sets the intent document types a client may submit to request mutation.
+        /// </summary>
+        [Key("intentDocumentTypes")] public string[]? IntentDocumentTypes { get; set; }
+        /// <summary>
+        /// Gets or sets the receipt document types emitted after a successful mutation path.
+        /// </summary>
+        [Key("receiptDocumentTypes")] public string[]? ReceiptDocumentTypes { get; set; }
+        /// <summary>
+        /// Gets or sets freeform notes that explain local mutation guardrails or posture.
+        /// </summary>
+        [Key("notes")] public string[]? Notes { get; set; }
+    }
+
     /// <summary>
     /// Marker interface for the explicit modern CultNet schema-v0 message family.
     /// </summary>
@@ -127,6 +190,10 @@ namespace GameCult.Networking
         /// </summary>
         [Key("supportedDocumentTypes")] public string[]? SupportedDocumentTypes { get; set; }
         /// <summary>
+        /// Gets or sets the supported mutation contracts.
+        /// </summary>
+        [Key("supportedMutationContracts")] public CultNetDocumentMutationContract[]? SupportedMutationContracts { get; set; }
+        /// <summary>
         /// Gets or sets the supported message versions.
         /// </summary>
         [Key("supportedMessageVersions")] public string[]? SupportedMessageVersions { get; set; }
diff --git a/src/GameCult.Networking/CultNetSchemaRegistry.cs b/src/GameCult.Networking/CultNetSchemaRegistry.cs
index 90c2a273..025afa3f 100644
--- a/src/GameCult.Networking/CultNetSchemaRegistry.cs
+++ b/src/GameCult.Networking/CultNetSchemaRegistry.cs
@@ -260,6 +260,12 @@ namespace GameCult.Networking
                 WireContracts = new[] { CultNetWireContracts.SchemaV0 }
             },
             new SchemaResourceSpec
+            {
+                FileName = "cultnet.document-mutation-contract.schema.json",
+                Kind = "shared_contract",
+                WireContracts = new[] { CultNetWireContracts.SchemaV0 }
+            },
+            new SchemaResourceSpec
             {
                 FileName = "cultnet.login.schema.json",
                 Kind = "wire_message",