diff --git a/workflow/Snakefile b/workflow/Snakefile
index 7a9c16f..1a99611 100644
--- a/workflow/Snakefile
+++ b/workflow/Snakefile
@@ -79,8 +79,7 @@ rule run_ecg:
   input:
     "flake.nix",
     "flake.lock",
-    ecg="ecg.py",
-    ecg_wrapper="workflow/scripts/ecg_wrapper.sh",
+    ecg="ecg/app/ecg.py",
     execo_wrapper="workflow/scripts/submission_g5k.py",
     oar_wrapper="workflow/scripts/ecg_oar_wrapper.oar.bash",
     artifact=f"{ARTIFACTS_FOLDER_JSON}/{{artifact}}.{EXTENSION}"
@@ -90,7 +89,20 @@ rule run_ecg:
     build_status  = f"{PREFIX}/build_status/{{artifact}}/{{date}}.csv",
     artifact_hash = f"{PREFIX}/artifact_hash/{{artifact}}/{{date}}.csv",
   shell:
-    (SHELLS_ECG["g5k"] if SYSTEM == "g5k" else "") + SHELLS_ECG["local"] + ("'" if SYSTEM == "g5k" else "")
+    (f"python3 {{input.execo_wrapper}} --path {os.getcwd()} \
+                                       --script {{input.oar_wrapper}} \
+                                       --site {config['site']} \
+                                       --cluster {config['cluster']} \
+                                       --max-duration {config['max_duration']} \
+                                       --checkpoint {config['checkpoint']} \
+                                     {'--besteffort' if config['besteffort'] else ''} \
+                                       --sleep_time {config['sleep_time']} \
+                                       --build_status_file {{output.build_status}} \
+                                       --artifact {{wildcards.artifact}} -- '" if SYSTEM == "g5k" else "") + \
+    """
+    nix develop .#ecg-shell --command ecg -p {output.pkg} -b {output.build_status} -a {output.artifact_hash} {output.artifact} &> {output.log} || echo "{input.artifact}, `date +%s.%N`, script_crash" > {output.build_status}
+    """ + \
+    ("'" if SYSTEM == "g5k" else "")
 
 rule update_blacklist:
   input:
diff --git a/workflow/scripts/ecg_oar_wrapper.oar.bash b/workflow/scripts/ecg_oar_wrapper.oar.bash
index 6d5238e..bef502f 100755
--- a/workflow/scripts/ecg_oar_wrapper.oar.bash
+++ b/workflow/scripts/ecg_oar_wrapper.oar.bash
@@ -17,7 +17,7 @@ export PATH=~/.local/bin:$PATH
 g5k-setup-docker -t
 
 handler() {
-    echo "${ARTIFACT_FILE}, `date +%s.%N`, job_time_exceeded" >> ${BUILD_STATUS_FILE}; exit 0;
+    echo "${ARTIFACT_FILE}, `date +%s.%N`, job_time_exceeded" > ${BUILD_STATUS_FILE}; exit 0;
 }
 trap handler SIGUSR2
 
diff --git a/workflow/scripts/ecg_wrapper.sh b/workflow/scripts/ecg_wrapper.sh
deleted file mode 100755
index 4195316..0000000
--- a/workflow/scripts/ecg_wrapper.sh
+++ /dev/null
@@ -1,14 +0,0 @@
-#!/bin/bash
-
-ECG=$1
-CONFIG=$2
-PKGLIST=$3
-BUILD_STATUS=$4
-ARTHASH_LOG=$5
-OUTPUT_LOG=$6
-
-python3 $ECG -p $PKGLIST -b $BUILD_STATUS -a $ARTHASH_LOG $CONFIG > $OUTPUT_LOG 2> $OUTPUT_LOG
-if [ $? -ne 0 ]
-then
-    echo "${CONFIG}, `date +%s.%N`, script_crash" >> ${BUILD_STATUS}; exit 0;
-fi