diff --git a/env/client/rest.http b/env/client/rest.http
index 18dfc13..dd0aa3f 100644
--- a/env/client/rest.http
+++ b/env/client/rest.http
@@ -1,33 +1,37 @@
 ### API v1
 
 GET http://localhost:8080/api/v1/10000000-2000-4000-8000-160000000004
-Accept: text/html
+Accept:        text/html
 Authorization: Bearer 10000000-2000-4000-8000-160000000003
+X-Request-ID:  10000000-2000-4000-8000-160000000000
 
 ###
 
 GET http://localhost:8080/api/v1/10000000-2000-4000-8000-160000000004
-Accept: application/json
+Accept:        application/json
 Authorization: Bearer 10000000-2000-4000-8000-160000000003
+X-Request-ID:  10000000-2000-4000-8000-160000000000
 
 ###
 
 GET http://localhost:8080/api/v1/10000000-2000-4000-8000-160000000004
-Accept: application/xml
+Accept:        application/xml
 Authorization: Bearer 10000000-2000-4000-8000-160000000003
+X-Request-ID:  10000000-2000-4000-8000-160000000000
 
 ###
 
 GET http://localhost:8080/api/v1/10000000-2000-4000-8000-160000000004
-Accept: text/plain
+Accept:        text/plain
 Authorization: Bearer 10000000-2000-4000-8000-160000000003
+X-Request-ID:  10000000-2000-4000-8000-160000000000
 
 ###
 
 POST http://localhost:8080/api/v1/10000000-2000-4000-8000-160000000004
-Content-Type: application/x-www-form-urlencoded
-Cookie: identifier=10000000-2000-4000-8000-160000000000
-X-Request-ID: 10000000-2000-4000-8000-160000000011
+Content-Type:  application/x-www-form-urlencoded
+X-Passport-ID: 10000000-2000-4000-8000-160000000000
+X-Request-ID:  10000000-2000-4000-8000-160000000000
 
 email=test@my.email
 
diff --git a/env/docker/compose/docker-compose.base.yml b/env/docker/compose/docker-compose.base.yml
index 0caabd4..11e89ef 100644
--- a/env/docker/compose/docker-compose.base.yml
+++ b/env/docker/compose/docker-compose.base.yml
@@ -4,14 +4,14 @@ services:
 
   db:
     image: postgres:10-alpine # https://hub.docker.com/_/postgres/
-    env_file: .env
+    env_file: ../../.env
 
   migration:
     image: kamilsk/form-api:3.x # https://hub.docker.com/r/kamilsk/form-api/
     command: [ "migrate" ]
     depends_on:
     - db
-    env_file: .env
+    env_file: ../../.env
     restart: on-failure
 
   service:
@@ -19,14 +19,13 @@ services:
     command: [ "run", "--with-profiling", "--with-monitoring" ]
     depends_on:
     - migration
-    env_file: .env
+    env_file: ../../.env
 
   server:
     image: kamilsk/nginx:alpine # https://hub.docker.com/r/kamilsk/nginx/
     depends_on:
     - service
-    env_file: .env
-    restart: on-failure
+    env_file: ../../.env
     volumes:
     - ./etc/nginx.conf:/etc/nginx/nginx.conf:ro
     - ./etc/service.conf:/etc/nginx/conf.d/default.conf:ro
diff --git a/pkg/domain/event_http.go b/pkg/domain/event_http.go
index 7db0f3d..5bcdeac 100644
--- a/pkg/domain/event_http.go
+++ b/pkg/domain/event_http.go
@@ -6,10 +6,12 @@ import (
 )
 
 const (
-	cookieHeader    = "Cookie"
-	optionsHeader   = "X-Forma-Options"
-	refererHeader   = "Referer"
-	userAgentHeader = "User-Agent"
+	cookieHeader     = "Cookie"
+	identifierHeader = "X-Passport-ID"
+	optionsHeader    = "X-Forma-Options"
+	refererHeader    = "Referer"
+	requestHeader    = "X-Request-ID"
+	userAgentHeader  = "User-Agent"
 )
 
 // FromCookies returns converted value from request's cookies.
@@ -44,6 +46,16 @@ func (context InputContext) Header(key string) string {
 	return http.Header(context.Headers).Get(key)
 }
 
+// Identifier TODO issue#173
+func (context InputContext) Identifier() *ID {
+	header := context.Header(identifierHeader)
+	if header != "" {
+		id := ID(header)
+		return &id
+	}
+	return nil
+}
+
 // Option TODO issue#173
 func (context InputContext) Option() Option {
 	split := func(str string) []string {
@@ -74,6 +86,16 @@ func (context InputContext) Referer() string {
 	return context.Header(refererHeader)
 }
 
+// Request TODO issue#173
+func (context InputContext) Request() *ID {
+	header := context.Header(requestHeader)
+	if header != "" {
+		id := ID(header)
+		return &id
+	}
+	return nil
+}
+
 // UserAgent TODO issue#173
 func (context InputContext) UserAgent() string {
 	return context.Header(userAgentHeader)
diff --git a/pkg/service/service.go b/pkg/service/service.go
index b7d5636..fdc3204 100644
--- a/pkg/service/service.go
+++ b/pkg/service/service.go
@@ -94,7 +94,7 @@ func (service *Forma) HandleInput(ctx context.Context, req v1.PostRequest) (resp
 			SchemaID:   req.ID,
 			InputID:    input.ID,
 			TemplateID: req.InputData.Template(),
-			Identifier: nil, // TODO issue#171
+			Identifier: req.Context.Identifier(),
 			Context:    req.Context,
 			Code:       http.StatusFound, // TODO issue#design
 			URL:        resp.URL,