diff --git a/docs/learn/tests/getting-started/plans/local/local.cue b/docs/learn/tests/getting-started/plans/local/local.cue
index a9460987..63ed78d3 100644
--- a/docs/learn/tests/getting-started/plans/local/local.cue
+++ b/docs/learn/tests/getting-started/plans/local/local.cue
@@ -3,6 +3,7 @@ package todoapp
 import (
 	"alpha.dagger.io/dagger"
 	"alpha.dagger.io/docker"
+	"alpha.dagger.io/http"
 )
 
 // docker local socket
@@ -24,10 +25,16 @@ registry: docker.#Run & {
 	socket: dockerSocket
 }
 
+// As we pushed the registry to our local docker
+// we need to wait for the container to be up
+wait: http.#Wait & {
+	url: "localhost:5042"
+}
+
 // push to our local registry
 // this concrete value satisfies the string constraint
 // we defined in the previous file
-push: target: "localhost:5042/todoapp"
+push: target: "\(wait.url)/todoapp"
 
 // Application URL
 appURL: "http://localhost:8080/" & dagger.#Output
diff --git a/docs/learn/tests/getting-started/plans/todoapp.cue b/docs/learn/tests/getting-started/plans/todoapp.cue
index 8fa8b0cd..e3812196 100644
--- a/docs/learn/tests/getting-started/plans/todoapp.cue
+++ b/docs/learn/tests/getting-started/plans/todoapp.cue
@@ -2,9 +2,9 @@ package todoapp
 
 import (
 	"alpha.dagger.io/dagger"
-	"alpha.dagger.io/os"
 	"alpha.dagger.io/docker"
 	"alpha.dagger.io/js/yarn"
+	"alpha.dagger.io/os"
 )
 
 // Build the source code using Yarn
diff --git a/docs/reference/http.md b/docs/reference/http.md
index 71d6e0b9..41c83cd6 100644
--- a/docs/reference/http.md
+++ b/docs/reference/http.md
@@ -72,3 +72,15 @@ _No input._
 | -------------    |:-------------:    |:-------------:     |
 |*statusCode*      | `string`          |-                   |
 |*body*            | `string`          |-                   |
+
+## http.#Wait
+
+URL listener Creates a dependency on URL
+
+### http.#Wait Inputs
+
+_No input._
+
+### http.#Wait Outputs
+
+_No output._
diff --git a/stdlib/.dagger/env/docker-pull/values.yaml b/stdlib/.dagger/env/docker-pull/values.yaml
index 75138a21..1ddc3303 100644
--- a/stdlib/.dagger/env/docker-pull/values.yaml
+++ b/stdlib/.dagger/env/docker-pull/values.yaml
@@ -3,7 +3,7 @@ plan:
 name: docker-pull
 inputs:
     ref:
-        text: docker.io/daggerio/ci-test:pncdyzkdemof@sha256:b92cbbfef6b952befc38812cd88cf5c4c1012f6df2891595c226f56cc053334e
+        text: docker.io/daggerio/ci-test:tyrgcrtlasex@sha256:3b308dec2f3d4c563b9c71ce4ddc660e476b899d06fa37f3b9fef350c1062a1f
 sops:
     kms: []
     gcp_kms: []
@@ -19,8 +19,8 @@ sops:
             SG1raUVNTzZIWDltV1pOS3hySHlJeWcKg3blmstOGcxtPww513+mAEA0MWOXwNAT
             5ngRvG6MraW3g9dhIuUYOwjuJyz1Z07/DBEocSxnjSyw45ZCkM1/9Q==
             -----END AGE ENCRYPTED FILE-----
-    lastmodified: "2021-08-31T10:10:02Z"
-    mac: ENC[AES256_GCM,data:30qNlAVLJunPEboTzeIxcsZ06LcLiDiXXJLVqHE328hcezcOYGsvhlYTiGEzxtAsv78Mwxw54oSbiFZmCKoew9bTZFUyb6FcFVk4GG8z2I8pn7FkZlcnEknWinVf9Tc/h5R/g4/BBGzsBf2dr4fx4ADewwO2z1Df/8wdup0PD4E=,iv:KJcMdpLCfSU1LvvPMXitSPzm0JPwrDWdLncdvVFngNk=,tag:X2/D+RhEnyizZHXJWYnmmg==,type:str]
+    lastmodified: "2021-11-23T18:15:32Z"
+    mac: ENC[AES256_GCM,data:+HpG1ZDND1Japu1hLgTVKF6CfEUbYp+sEBpv0WtsCHcHGYeYVkZT8ZJKajWlz8uFfikpKv76FkBw8XqKVXyPZYTQWuo9VvmPTF5HajiVE6kP5Ax3/5Sh7ecwfGdbqE3mQoj+jaQE8NBnGbCBljij/xFYW63fIaurqsyPWTQl2YI=,iv:fBPseUNueHO4ZUnlwDljfAwUvi4UyjGysXMTCmoAgYw=,tag:Pg4dGX4/05SahATlE6zrsA==,type:str]
     pgp: []
     encrypted_suffix: secret
     version: 3.7.1
diff --git a/stdlib/.dagger/env/http/values.yaml b/stdlib/.dagger/env/http/values.yaml
index 76b6c328..7ef0dfa9 100644
--- a/stdlib/.dagger/env/http/values.yaml
+++ b/stdlib/.dagger/env/http/values.yaml
@@ -1,6 +1,10 @@
 plan:
     package: ./http/tests
 name: http
+inputs:
+    TestDockersocket:
+        socket:
+            unix: /var/run/docker.sock
 sops:
     kms: []
     gcp_kms: []
@@ -16,8 +20,8 @@ sops:
             NHkxc1VXWHBwZFN5WFNxamdPaGZLM3MKaZra2gWvKl7+pXSihV70/mQYel9697z2
             eBSMuRPuZSjrg3JCBLhXTdIgUYxbMgWhILLpN5UqhTBVboUlRsURQA==
             -----END AGE ENCRYPTED FILE-----
-    lastmodified: "2021-10-19T11:50:42Z"
-    mac: ENC[AES256_GCM,data:iG/JWnCk8UpThscQBqd9l7R7k1Xae1ED7WbYqPQmK5GRXhb7hIZGENnjn1aARnFjlCtEob6WvutWaZe7q1P90ZCirwXVBGewAeHchHqFA0KmUORRdtjMkZjnlRLMDKYu6CeNkaVK1al+B87CPlCBKz5UMeL9gnvug0k298AxWLY=,iv:RZEtSdbkxwgq5xEucnC+qyD2RCMk1DuaShjCh5Ihe5M=,tag:swW4R7ni0zoxOrc9lrV9Ww==,type:str]
+    lastmodified: "2021-11-23T17:30:31Z"
+    mac: ENC[AES256_GCM,data:R82VFQG+vtFoH/H4R3TGfFzcmEBLRWv81/pfbYIoWGTH3iFmVgfiCXuqF2O4suhG6mlmiGVDCFBBGPfFvOIBPSwbAqOoNQrM+pXPk3nrm3KY6RLSiByZX3yS1G2HHzGSbQVDuxlTBGyXhpJZs1ZgysZguHUqtunbrjSpD4+iWE8=,iv:LhTwB1QKXCXz9tu03d5NHIv/Jwrgg3LXQYafXykFz/o=,tag:h0mgHTyfxflAuv/uYuRibw==,type:str]
     pgp: []
     encrypted_suffix: secret
     version: 3.7.1
diff --git a/stdlib/.dagger/env/sanity-check/plan/cue.mod/pkg/.gitignore b/stdlib/.dagger/env/sanity-check/plan/cue.mod/pkg/.gitignore
index a572e9ee..2d4dc1ae 100644
--- a/stdlib/.dagger/env/sanity-check/plan/cue.mod/pkg/.gitignore
+++ b/stdlib/.dagger/env/sanity-check/plan/cue.mod/pkg/.gitignore
@@ -1,2 +1,3 @@
-# dagger universe
+# generated by dagger
 alpha.dagger.io
+dagger.lock
diff --git a/stdlib/cue.mod/pkg/.gitignore b/stdlib/cue.mod/pkg/.gitignore
index a572e9ee..2d4dc1ae 100644
--- a/stdlib/cue.mod/pkg/.gitignore
+++ b/stdlib/cue.mod/pkg/.gitignore
@@ -1,2 +1,3 @@
-# dagger universe
+# generated by dagger
 alpha.dagger.io
+dagger.lock
diff --git a/stdlib/http/http.cue b/stdlib/http/http.cue
index d5b99145..2628324f 100644
--- a/stdlib/http/http.cue
+++ b/stdlib/http/http.cue
@@ -6,6 +6,7 @@ import (
 
 	"alpha.dagger.io/alpine"
 	"alpha.dagger.io/dagger"
+	"alpha.dagger.io/dagger/op"
 	"alpha.dagger.io/os"
 )
 
@@ -84,3 +85,70 @@ import (
 		"statusCode": strconv.Atoi(statusCode)
 	}
 }
+
+// URL listener
+// Creates a dependency on URL
+#Wait: {
+	// URL to listen
+	url: string
+
+	// Waiting time between checks (sec.)
+	interval: int | *30
+
+	// Max amount of retries
+	retries: int | *3
+
+	// Max initialization time (sec.)
+	startPeriod: int | *0
+
+	// Time until timeout (sec.)
+	timeout: int | *30
+
+	#up: [
+		op.#Load & {
+			from: alpine.#Image & {
+				package: bash: "=~5.1"
+				package: curl: true
+			}
+		},
+		op.#Exec & {
+			args: ["/bin/bash", "-c",
+				#"""
+					# (f: str -> int)
+					nb_retries=$(($NB_RETRIES+0))
+					starting_period=$(($START_PERIOD+0))
+
+					status="0"
+					SECONDS=0
+					# START_PERIOD implementation
+					while [ $SECONDS -lt $starting_period ]; do
+						status="$(curl --connect-timeout 1 -s -o /dev/null -w ''%{http_code}'' $HEALTH_URL)"
+						if [ "$status" == "200" ]; then
+							exit 0;
+						fi
+						sleep 1;
+					done
+
+					# TIMEOUT, INTERVAL, INTERVAL implementation
+					for ((i=0;i<NB_RETRIES;i++)); do
+						status="$(curl --connect-timeout $TIMEOUT -s -o /dev/null -w ''%{http_code}'' $HEALTH_URL)"
+						if [ "$status" == "200" ]; then
+							exit 0;
+						fi
+						sleep "$INTERVAL";
+					done
+
+					exit 1;
+					"""#,
+			]
+			always: true
+			env: {
+				HEALTH_URL:   url
+				INTERVAL:     "\(interval)"
+				NB_RETRIES:   "\(retries)"
+				START_PERIOD: "\(startPeriod)"
+				TIMEOUT:      "\(timeout)"
+			}
+		},
+	]
+}
diff --git a/stdlib/http/tests/http.cue b/stdlib/http/tests/http.cue
index ed7b6945..a512b633 100644
--- a/stdlib/http/tests/http.cue
+++ b/stdlib/http/tests/http.cue
@@ -2,13 +2,44 @@ package http
 
 import (
 	"alpha.dagger.io/alpine"
+	"alpha.dagger.io/dagger"
+	"alpha.dagger.io/docker"
 	"alpha.dagger.io/os"
+	"alpha.dagger.io/random"
 )
 
+TestDockersocket: dagger.#Stream & dagger.#Input
+
+TestSuffix: random.#String & {
+	seed: ""
+}
+
+TestRun: docker.#Run & {
+	name:   "daggerci-test-wait-\(TestSuffix.out)"
+	ref:    "nginx"
+	socket: TestDockersocket
+	ports: ["8088:80"]
+}
+
+// Waits for TestRun to finish initializing
+Testhealth: #Wait & {
+	url: "http://localhost:8088/"
+}
+
+TestWait: query: os.#Container & {
+	image: alpine.#Image & {
+		package: bash: "=~5.1"
+		package: curl: true
+	}
+	command: #"""
+		test "$(curl -L --fail --silent --show-error --write-out "%{http_code}" "$URL" -o /dev/null)" = "200"
+		"""#
+	env: URL: Testhealth.url
+}
+
 TestRequest: {
 	req: #Get & {
-		url: "https://api.github.com/"
-		request: header: Accept: "application/json"
+		url: Testhealth.url
 	}
 
 	testRaw: os.#Container & {
@@ -24,9 +55,8 @@ TestRequest: {
 		shell: args: ["--noprofile", "--norc", "-eo", "pipefail", "-c"]
 		command: #Command
 	}
+	#Command: #"""
+		cat /content.json | grep -q nginx >/dev/null
+		test "$STATUS" = "200"
+		"""#
 }
-
-#Command: #"""
-	test "$(cat /content.json | jq -r .current_user_url)" = 'https://api.github.com/user'
-	test "$STATUS" = "200"
-	"""#
diff --git a/stdlib/universe.bats b/stdlib/universe.bats
index 86dbeec2..485ab84c 100644
--- a/stdlib/universe.bats
+++ b/stdlib/universe.bats
@@ -24,7 +24,9 @@ setup() {
 }
 
 @test "http" {
-  dagger -e http up 
+  dagger -e http up
+  CONTAINER=$(docker container ls -q --filter "name=daggerci-test-wait-*")
+  docker stop "$CONTAINER" && docker rm "$CONTAINER"
 }
 
 @test "js/yarn" {
@@ -86,7 +88,8 @@ setup() {
 @test "docker run: ports" {
   dagger -e docker-run-ports up
   CONTAINER=$(docker container ls -q --filter "name=daggerci-test-ports-*")
-  until docker inspect --format "{{json .State.Status }}" "$CONTAINER" | grep -m 1 "running"; do sleep 1 ; done
+  SECONDS=0 
+  while [[ "$(docker inspect --format '{{json .State.Status }}' todoapp | grep -m 1 'running')" != "running" && $SECONDS -lt 45 ]]; do sleep 1 ; done
   run curl -f -LI http://localhost:8080
   assert_output --partial '200 OK'
   docker stop "$CONTAINER" && docker rm "$CONTAINER"