diff --git a/metexplore3-api.yml b/metexplore3-api.yml
index 76d8c03ea8096a0e2ed0170ae409d0a5bf397eb9..a780257690036507a806a18c231fe29739297ed9 100644
--- a/metexplore3-api.yml
+++ b/metexplore3-api.yml
@@ -41,21 +41,33 @@ paths:
 
   /pathways:
     $ref: "paths/pathways/pathways.yml"
+  /pathways/count:
+    $ref: "paths/pathways/count.yml"
 
   /reactions:
     $ref: "paths/reactions/reactions.yml"
+  /reactions/count:
+    $ref: "paths/reactions/count.yml"
 
   /metabolites:
     $ref: "paths/metabolites/metabolites.yml"
+  /metabolites/count:
+    $ref: "paths/metabolites/count.yml"
 
   /enzymes:
     $ref: "paths/enzymes/enzymes.yml"
+  /enzymes/count:
+    $ref: "paths/enzymes/count.yml"
 
   /proteins:
     $ref: "paths/proteins/proteins.yml"
+  /proteins/count:
+    $ref: "paths/proteins/count.yml"
 
   /genes:
     $ref: "paths/genes/genes.yml"
+  /genes/count:
+    $ref: "paths/genes/count.yml"
 
   /filter:
     $ref: "paths/filters/get.yml"
diff --git a/paths/analyses/add.yml b/paths/analyses/add.yml
index d4c06eb5d0d80c4d94f3e2f1262863c78c604af3..d7887c6e2dee9abf8fa2099a776ceb647bfc6f7c 100644
--- a/paths/analyses/add.yml
+++ b/paths/analyses/add.yml
@@ -8,9 +8,7 @@ requestBody:
   content:
     application/json:
       schema:
-        type: object
-        items:
-          $ref: ../../schemas/analyses/AnalysesResponse.yml
+        $ref: ../../schemas/analyses/Analysis.yml
 responses:
   200:
     description: successful operation
diff --git a/paths/analyses/update.yml b/paths/analyses/update.yml
index ba826263a0c53f8fa0d4fcec487672757461da20..b889d39691d79f6902699cbfda6fe6f4e1297469 100644
--- a/paths/analyses/update.yml
+++ b/paths/analyses/update.yml
@@ -8,9 +8,7 @@ requestBody:
   content:
     application/json:
       schema:
-        type: object
-        items:
-          $ref: ../../schemas/analyses/AnalysesResponse.yml
+        $ref: ../../schemas/analyses/Analysis.yml
 responses:
   200:
     description: successful operation
diff --git a/paths/enzymes/count.yml b/paths/enzymes/count.yml
new file mode 100644
index 0000000000000000000000000000000000000000..5c86c6a24d05fd1d210c5425b91b015bce0ad76d
--- /dev/null
+++ b/paths/enzymes/count.yml
@@ -0,0 +1,23 @@
+get:
+  tags:
+    - Enzymes
+  summary: count ligns Enzyme
+  description: get the number of enzymes for one biosource
+  operationId: countEnzymes
+  x-eov-operation-handler: enzymes
+  parameters:
+    - name: idBioSource
+      in: query
+      description: the idBioSource for the Enzyme
+      required: true
+      schema:
+        type: integer
+  responses:
+    200:
+      description: successful operation
+      content:
+        application/json:
+          schema:
+            $ref: ../../schemas/utils/CountResponse.yml
+    404:
+      $ref: ../../responses/notFound.yml
diff --git a/paths/genes/count.yml b/paths/genes/count.yml
new file mode 100644
index 0000000000000000000000000000000000000000..49c9d9bc4a8a7a41a7b55ff7b32f451e0f9b1ae8
--- /dev/null
+++ b/paths/genes/count.yml
@@ -0,0 +1,23 @@
+get:
+  tags:
+    - Genes
+  summary: count ligns Genes
+  description: get the number of genes for one biosource
+  operationId: countGenes
+  x-eov-operation-handler: genes
+  parameters:
+    - name: idBioSource
+      in: query
+      description: the idBioSource for the genes
+      required: true
+      schema:
+        type: integer
+  responses:
+    200:
+      description: successful operation
+      content:
+        application/json:
+          schema:
+            $ref: ../../schemas/utils/CountResponse.yml
+    404:
+      $ref: ../../responses/notFound.yml
diff --git a/paths/metabolites/count.yml b/paths/metabolites/count.yml
new file mode 100644
index 0000000000000000000000000000000000000000..393b77724d178ebb1d012574110731593326144e
--- /dev/null
+++ b/paths/metabolites/count.yml
@@ -0,0 +1,23 @@
+get:
+  tags:
+    - Metabolites
+  summary: count ligns Metabolites
+  description: get the number of metabolites for one biosource
+  operationId: countMetabolites
+  x-eov-operation-handler: metabolites
+  parameters:
+    - name: idBioSource
+      in: query
+      description: the idBioSource for the metabolites
+      required: true
+      schema:
+        type: integer
+  responses:
+    200:
+      description: successful operation
+      content:
+        application/json:
+          schema:
+            $ref: ../../schemas/utils/CountResponse.yml
+    404:
+      $ref: ../../responses/notFound.yml
diff --git a/paths/pathways/count.yml b/paths/pathways/count.yml
new file mode 100644
index 0000000000000000000000000000000000000000..1fcd3e15c655d99e07a4d0b8ec7980e036062fc7
--- /dev/null
+++ b/paths/pathways/count.yml
@@ -0,0 +1,23 @@
+get:
+  tags:
+    - Pathways
+  summary: count ligns Pathways
+  description: get the number of pathways for one biosource
+  operationId: countPathways
+  x-eov-operation-handler: pathways
+  parameters:
+    - name: idBioSource
+      in: query
+      description: the idBioSource for the pathways
+      required: true
+      schema:
+        type: integer
+  responses:
+    200:
+      description: successful operation
+      content:
+        application/json:
+          schema:
+            $ref: ../../schemas/utils/CountResponse.yml
+    404:
+      $ref: ../../responses/notFound.yml
diff --git a/paths/proteins/count.yml b/paths/proteins/count.yml
new file mode 100644
index 0000000000000000000000000000000000000000..afff9f6f96b57494e7ba9af3788185f066afccf5
--- /dev/null
+++ b/paths/proteins/count.yml
@@ -0,0 +1,23 @@
+get:
+  tags:
+    - Proteins
+  summary: count ligns Proteins
+  description: get the number of proteins for one biosource
+  operationId: countProteins
+  x-eov-operation-handler: proteins
+  parameters:
+    - name: idBioSource
+      in: query
+      description: the idBioSource for the proteins
+      required: true
+      schema:
+        type: integer
+  responses:
+    200:
+      description: successful operation
+      content:
+        application/json:
+          schema:
+            $ref: ../../schemas/utils/CountResponse.yml
+    404:
+      $ref: ../../responses/notFound.yml
diff --git a/paths/reactions/count.yml b/paths/reactions/count.yml
new file mode 100644
index 0000000000000000000000000000000000000000..d3d15486b50b677ed79399affa6327ad2b9c6611
--- /dev/null
+++ b/paths/reactions/count.yml
@@ -0,0 +1,23 @@
+get:
+  tags:
+    - Reactions
+  summary: count ligns Reactions
+  description: get the number of reactions for one biosource
+  operationId: countReactions
+  x-eov-operation-handler: reactions
+  parameters:
+    - name: idBioSource
+      in: query
+      description: the idBioSource for the reactions
+      required: true
+      schema:
+        type: integer
+  responses:
+    200:
+      description: successful operation
+      content:
+        application/json:
+          schema:
+            $ref: ../../schemas/utils/CountResponse.yml
+    404:
+      $ref: ../../responses/notFound.yml
diff --git a/paths/steps/add.yml b/paths/steps/add.yml
index 0237d4262a9832c171d08a0e9f682a48c432a61a..b8306531284a5680a0e94edff5369c44d2d799c4 100644
--- a/paths/steps/add.yml
+++ b/paths/steps/add.yml
@@ -17,4 +17,6 @@ responses:
     content:
       application/json:
         schema:
-          $ref: ../../schemas/steps/StepResponse.yml
\ No newline at end of file
+          $ref: ../../schemas/steps/StepResponse.yml
+  404:
+    $ref: ../../responses/notFound.yml
\ No newline at end of file
diff --git a/paths/steps/get.yml b/paths/steps/get.yml
index ad66a0fc5b8e5e4c3ac263dc5da3ef7b8e11182e..086ff157a68871ab9f0fd00a65ef8259f937968a 100644
--- a/paths/steps/get.yml
+++ b/paths/steps/get.yml
@@ -24,3 +24,5 @@ responses:
       application/json:
         schema:
           $ref: "../../schemas/steps/StepResponse.yml"
+  404:
+    $ref: ../../responses/notFound.yml
diff --git a/schemas/utils/CountResponse.yml b/schemas/utils/CountResponse.yml
new file mode 100644
index 0000000000000000000000000000000000000000..390800bfbe3b2a7cb0b2a18eb5527bd0dcc3148a
--- /dev/null
+++ b/schemas/utils/CountResponse.yml
@@ -0,0 +1,6 @@
+allOf:
+  - $ref: '../utils/BaseResponse.yml'
+  - type: object
+  - properties:
+      count:
+        type: integer