diff --git a/src/openapi/fiko/fiko-crud.yaml b/src/openapi/fiko/fiko-crud.yaml
index 59068c9..1fdd3fe 100644
--- a/src/openapi/fiko/fiko-crud.yaml
+++ b/src/openapi/fiko/fiko-crud.yaml
@@ -278,7 +278,7 @@ paths:
                 {
                   "processingFailureId": "afce35b2-1dff-4ace-98d0-4b9ac405c87d",
                 }
-  /transactionitems/{transactionItemId}/transactionaudittrail:
+  /transactionitems/{transactionItemId}/transactionaudittrails:
     parameters:
       - in: path
         name: transactionItemId
@@ -288,30 +288,6 @@ paths:
           example: 9834b346-d68c-438d-9bd5-6716422c2657
         required: true
         description: The id of the transaction item to process.
-    get:
-      summary: Get all audit trail entries for a transaction.
-      description: Get all audit trail entries for a transaction.
-      tags:
-        - Audit Trail v2
-      responses:
-        "200":
-          description: OK
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/unavailable"
-              example:
-                [
-                  {
-                    "transactionAuditTrailId": "afce35b2-1dff-4ace-98d0-4b9ac405c87d",
-                    "transactionItemId": "d667d293-aa82-4c9e-9b10-77cffc9058a1",
-                    "user": "fiko",
-                    "timestamp": "2022-01-01 00:00:00",
-                    "action": "created",
-                    "description": "Transaction created.",
-                    "correlationId": "a3891560-3084-42cb-867c-f289e7cda47d",
-                  },
-                ]
     post:
       summary: Add an audit trail entry.
       description: Add an audit trail entry.
@@ -342,6 +318,86 @@ paths:
                 {
                   "transactionAuditTrailId": "afce35b2-1dff-4ace-98d0-4b9ac405c87d",
                 }
+  /transactionaudittrails:
+    get:
+      summary: Find audit trail entries.
+      description: Find audit trail entries.
+      tags:
+        - Audit Trail v2
+      parameters:
+        - in: query
+          name: transactionAuditTrailId
+          schema:
+            type: string
+            format: uuid
+            example: 498e11fd-86c7-4e26-8ca9-c5ed9049da9e
+          required: true
+          description: The id of the audit trail.
+        - in: query
+          name: transactionItemId
+          schema:
+            type: string
+            format: uuid
+            example: 9834b346-d68c-438d-9bd5-6716422c2657
+          required: true
+          description: The id of the transaction item.
+        - in: query
+          name: user
+          schema:
+            type: string
+            example: fiko
+          description: The user who created the audit trail.
+        - in: query
+          name: timestampBefore
+          schema:
+            type: string
+            example: 2022-01-01 00:00:00
+          description: The timestamp before the event occured.
+        - in: query
+          name: timestampAfter
+          schema:
+            type: string
+            example: 2022-01-01 00:00:00
+          description: The timestamp after the event occured.
+        - in: query
+          name: action
+          schema:
+            type: array
+            items:
+              type: string
+            example: [created, succeeded, failed]
+          description: The action of the event.
+        - in: query
+          name: description
+          schema:
+            type: string
+            example: Transaction created.
+          description: The description of the event.
+        - in: query
+          name: correlationId
+          schema:
+            type: string
+            example: a3891560-3084-42cb-867c-f289e7cda47d
+          description: The correlation id of the event.
+      responses:
+        "200":
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/unavailable"
+              example:
+                [
+                  {
+                    "transactionAuditTrailId": "afce35b2-1dff-4ace-98d0-4b9ac405c87d",
+                    "transactionItemId": "d667d293-aa82-4c9e-9b10-77cffc9058a1",
+                    "user": "fiko",
+                    "timestamp": "2022-01-01 00:00:00",
+                    "action": "created",
+                    "description": "Transaction created.",
+                    "correlationId": "a3891560-3084-42cb-867c-f289e7cda47d",
+                  },
+                ]
   /processingfailures:
     get:
       summary: Find processing failures.
@@ -509,8 +565,8 @@ paths:
                 { "productMetadataId": "39a87c2a-9011-4dfd-b35e-1245a98c2e61" }
   /contraaccountmetadata:
     get:
-      summary: Get contra account metadata.
-      description: Get contra account metadata.
+      summary: Find contra account metadata.
+      description: Find contra account metadata.
       tags:
         - Metadata v2
       parameters:
@@ -618,8 +674,8 @@ paths:
                 }
   /taxmetadata:
     get:
-      summary: Get tax metadata.
-      description: Get tax metadata.
+      summary: Find tax metadata.
+      description: Find tax metadata.
       tags:
         - Metadata v2
       parameters:
@@ -757,8 +813,8 @@ paths:
                 { "taxMetadataId": "37a8095b-19db-498f-9349-5f37d21c5bdf" }
   /sourcemetadata:
     get:
-      summary: Get source metadata.
-      description: Get source metadata.
+      summary: Find source metadata.
+      description: Find source metadata.
       tags:
         - Metadata v2
       parameters:
@@ -907,8 +963,8 @@ paths:
                 { "sourceMetadataId": "37a8095b-19db-498f-9349-5f37d21c5bdf" }
   /accountingperiodmetadata:
     get:
-      summary: Get accounting period metadata.
-      description: Get accounting period metadata.
+      summary: Find accounting period metadata.
+      description: Find accounting period metadata.
       tags:
         - Metadata v2
       parameters:
@@ -1004,8 +1060,8 @@ paths:
                 }
   /concessionmetadata:
     get:
-      summary: Get concession metadata.
-      description: Get concession metadata.
+      summary: Find concession metadata.
+      description: Find concession metadata.
       tags:
         - Metadata v2
       parameters:
@@ -1020,8 +1076,10 @@ paths:
         - in: query
           name: concessionId
           schema:
-            type: integer
-            example: 1
+            type: array
+            items:
+              type: integer
+            example: [1, 2]
           description: The id of the concession.
         - in: query
           name: percentage
@@ -1046,14 +1104,14 @@ paths:
                 [
                   {
                     "concessionMetadataId": "37a8095b-19db-498f-9349-5f37d21c5bdf",
-                    "concession": { "concessionId": 1, "name": "RAIL" },
+                    "concession": { "concessionId": 1, "name": "rail" },
                     "percentage": 84.021,
                     "validFrom": "2024-01-01T00:00:00.000",
                     "validUntil": null,
                   },
                   {
                     "concessionMetadataId": "5ac3a5a8-4b9b-4a6a-9b1f-86ae8d6d4a9b",
-                    "concession": { "concessionId": 2, "name": "BUS" },
+                    "concession": { "concessionId": 2, "name": "bus" },
                     "percentage": 15.979,
                     "validFrom": "2024-01-01T00:00:00.000",
                     "validUntil": null,
@@ -1127,6 +1185,60 @@ paths:
                 {
                   "concessionMetadataId": "37a8095b-19db-498f-9349-5f37d21c5bdf",
                 }
+  /concessions:
+    get:
+      summary: Get all concessions.
+      description: Get all concessions.
+      tags:
+        - References v2
+      responses:
+        "200":
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/unavailable"
+              example:
+                [
+                  {
+                    "concessionId": 1,
+                    "name": "rail",
+                  },
+                  {
+                    "concessionId": 2,
+                    "name": "bus",
+                  },
+                  {
+                    "concessionId": 3,
+                    "name": "not_applicable",
+                  },
+                ]
+  /failurereasons:
+    get:
+      summary: Get all failure reasons.
+      description: Get all failure reasons.
+      tags:
+        - References v2
+      responses:
+        "200":
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/unavailable"
+              example:
+                [
+                  {
+                    "failureReasonId": 1,
+                    "reasonCode": "002",
+                    "reasonDesc": "Contra account does not exist"
+                  },
+                  {
+                    "failureReasonId": 2,
+                    "reasonCode": "003",
+                    "reasonDesc": "Accouting period closed"
+                  },
+                ]
 components:
   securitySchemes:
     bearerToken: