diff --git a/src/chipster.nf b/src/chipster.nf
index 525d66a8e1e97b721db651bada67a8d7700358db..d753bffb4f707e74c70afdd0f237fd92be9c0bd5 100755
--- a/src/chipster.nf
+++ b/src/chipster.nf
@@ -51,7 +51,7 @@ params.project = ""
 
 /* Params from config file yaml: */
 
-data = params.config.collect {k , v -> "${params.fastq_folder}/${v.fastq.gz}"}
+data = params.input.collect {k , v -> "${params.fastq}/${v.fastq.gz}"}
 
 /* Params out */
 params.fastp_out = "$params.project/fastp/"
diff --git a/src/config.yml b/src/config.yml
index 1b3b999ece0cae4aad3bb797170721a0ea090901..2135abcdd0b58757e9df19aa98aa0807ff3a2d28 100644
--- a/src/config.yml
+++ b/src/config.yml
@@ -1,8 +1,24 @@
 input:
+  # A row defines some features to describe a sample to analyse.
+  # You can add as many row as you want below each other. Be sure that
+  # the name of the row is the same as the file name witout extension.
+
+  # project name, 
+
+  # boolean value to setup sequencing type (paired-end or single-end)
+  paired-end: FALSE
+
+  # directory containing fastq files (rawdata)
+  fastq_folder: ""
+
   row1:
-    sample: 5Y_siDDX_CTCF
+    # sample must be a string. It corresponds to the name of the sample
+    sample: "5Y_siDDX_CTCF"
+    # fastq is the corresponding fastq file, can be compressed as gz file.
     fastq: "5Y_siDDX_CTCF.fastq.gz"
+    # condition
     condition: "siDDX"
+    # type is related to ChIP type: Input or IP
     type: "IP"
     
   row2:
@@ -10,3 +26,8 @@ input:
     fastq: "5Y_siDDX_input.fastq.gz"
     condition: "siDDX"
     type: "Input"
+
+
+  # Under construction:
+  # Organism (hg19, GRCH38, HBV...) default hg19 for FasterDB compatibility
+  # organism: ""
\ No newline at end of file