diff --git a/proto/common/v1.proto b/proto/common/v1.proto
index 8a700ca7..5e085bef 100644
--- a/proto/common/v1.proto
+++ b/proto/common/v1.proto
@@ -14,6 +14,8 @@ message Common_1 {
   repeated Link links = 2;
   google.protobuf.Timestamp createdAt = 3 [(required) = true];
   google.protobuf.Timestamp updatedAt = 4 [(required) = true];
+  // 32-byte hash of the discovery key of a core
+  bytes createdBy = 5 [(required) = true];
 }
 /* ignored fields and differences from common.json jsonSchema
  * id is a byte buffer here and a string in jsonSchema
diff --git a/schema/common/v1.json b/schema/common/v1.json
index d86471d0..84e94e73 100644
--- a/schema/common/v1.json
+++ b/schema/common/v1.json
@@ -22,6 +22,10 @@
       "type": "string",
       "format": "date-time"
     },
+    "createdBy": {
+      "description": "id (hex-encoded 32-byte buffer) of the discovery key for the core that created the first version of this element",
+      "type": "string"
+    },
     "updatedAt": {
       "description": "RFC3339-formatted datetime of when this version of the element was created",
       "type": "string",
@@ -42,6 +46,7 @@
     "schemaName",
     "updatedAt",
     "links",
-    "versionId"
+    "versionId",
+    "createdBy"
   ]
 }
diff --git a/src/lib/decode-conversions.ts b/src/lib/decode-conversions.ts
index 9bd50e65..52583d32 100644
--- a/src/lib/decode-conversions.ts
+++ b/src/lib/decode-conversions.ts
@@ -250,5 +250,6 @@ function convertCommon(
     links: common.links.map((link) => getVersionId(link)),
     createdAt: common.createdAt,
     updatedAt: common.updatedAt,
+    createdBy: common.createdBy.toString('hex'),
   }
 }
diff --git a/src/lib/encode-converstions.ts b/src/lib/encode-converstions.ts
index 15f85ad2..5f5ef2c7 100644
--- a/src/lib/encode-converstions.ts
+++ b/src/lib/encode-converstions.ts
@@ -138,6 +138,7 @@ function convertCommon(
     docId: Buffer.from(common.docId, 'hex'),
     createdAt: common.createdAt,
     updatedAt: common.updatedAt,
+    createdBy: Buffer.from(common.createdBy, 'hex'),
     links: common.links.map((link) => parseVersionId(link)),
   }
 }
diff --git a/test/fixtures/cached.js b/test/fixtures/cached.js
index 58c5b950..bd9fecee 100644
--- a/test/fixtures/cached.js
+++ b/test/fixtures/cached.js
@@ -8,6 +8,7 @@ export const cachedValues = {
   projectId: randomBytes(32).toString('hex'),
   authorId: randomBytes(32).toString('hex'),
   coreId: randomBytes(32).toString('hex'),
+  createdBy: randomBytes(32).toString('hex'),
   createdAt: date,
   updatedAt: date,
   attachments: { driveId: randomBytes(32).toString('hex') },
diff --git a/test/fixtures/good-docs-completed.js b/test/fixtures/good-docs-completed.js
index f48f1116..81df7e44 100644
--- a/test/fixtures/good-docs-completed.js
+++ b/test/fixtures/good-docs-completed.js
@@ -16,6 +16,7 @@ export const goodDocsCompleted = [
       schemaName: 'observation',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       lat: 24.0424,
       lon: 21.0214,
@@ -74,6 +75,7 @@ export const goodDocsCompleted = [
       schemaName: 'projectSettings',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       defaultPresets: {
         point: cachedValues.defaultPresets.point,
@@ -93,6 +95,7 @@ export const goodDocsCompleted = [
       schemaName: 'field',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       tagKey: 'otherTagKey',
       type: 'number',
@@ -116,6 +119,7 @@ export const goodDocsCompleted = [
       schemaName: 'preset',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       name: 'myPreset',
       geometry: ['point', 'vertex', 'line'],
@@ -142,6 +146,7 @@ export const goodDocsCompleted = [
       schemaName: 'role',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       roleId: '6fd029a78243',
       fromIndex: 5,
@@ -155,6 +160,7 @@ export const goodDocsCompleted = [
       schemaName: 'deviceInfo',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       name: 'my device name',
     },
@@ -167,6 +173,7 @@ export const goodDocsCompleted = [
       schemaName: 'coreOwnership',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       authCoreId: Buffer.from('authCoreId').toString('hex'),
       configCoreId: Buffer.from('configCoreId').toString('hex'),
diff --git a/test/fixtures/good-docs-minimal.js b/test/fixtures/good-docs-minimal.js
index 916ae0c3..1ea78da3 100644
--- a/test/fixtures/good-docs-minimal.js
+++ b/test/fixtures/good-docs-minimal.js
@@ -18,6 +18,7 @@ export const goodDocsMinimal = [
       schemaName: 'observation',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       refs: [],
       attachments: [],
@@ -33,6 +34,7 @@ export const goodDocsMinimal = [
       schemaName: 'projectSettings',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
     },
     expected: {},
@@ -44,6 +46,7 @@ export const goodDocsMinimal = [
       schemaName: 'field',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       tagKey: 'myTagKey',
       label: 'my label',
@@ -58,6 +61,7 @@ export const goodDocsMinimal = [
       schemaName: 'preset',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       name: 'myPreset',
       geometry: ['point'],
@@ -76,6 +80,7 @@ export const goodDocsMinimal = [
       schemaName: 'role',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       roleId: '3b0104e370f9',
       fromIndex: 5,
@@ -89,6 +94,7 @@ export const goodDocsMinimal = [
       schemaName: 'deviceInfo',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       name: 'my device name',
     },
@@ -101,6 +107,7 @@ export const goodDocsMinimal = [
       schemaName: 'coreOwnership',
       createdAt: cachedValues.createdAt,
       updatedAt: cachedValues.updatedAt,
+      createdBy: cachedValues.createdBy,
       links: [],
       authCoreId: Buffer.from('authCoreId').toString('hex'),
       configCoreId: Buffer.from('configCoreId').toString('hex'),