diff --git a/Dockerfile b/Dockerfile
index fd53295..3bb0e96 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,6 @@
-FROM concourse/buildroot:git
+FROM alpine/git
+
+RUN apk add --no-cache curl curl-dev bash jq
 
 COPY scripts/ /opt/resource/
 RUN chmod +x /opt/resource/*
diff --git a/README.md b/README.md
index a24e01c..b79eb6e 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,10 @@ Updates the merge request's `merge_status` which displays nicely in the GitLab U
 * `repository`: The path of the repository of the merge request's source branch (required)
 * `status`: The new status of the merge request (required, can be either `pending`, `running`, `success`, `failed`, or `canceled`)
 * `build_label`: The label of the build in GitLab (optional, defaults to `"Concourse"`)
+* `comment`: Add a comment to the MRs open on the branch that is being target by concourse. Could be an object with `text/file(s)` fields.
+If just the `file(s)` or `text` is specified it is used to populate the field, if both file and text are specified then the file(s) is substituted in to the text comment.
+If only one file is specified (field `file`) then it replace `$FILE_CONTENT` in the text.
+If multiple files are specified (field `files`) then it replace a variable with the key of the file (look the example for a better clarification)
 
 ## Example
 
@@ -88,4 +92,14 @@ jobs:
     params:
       repository: repo
       status: success
+      comment:
+        files: 
+          original: in/comment.txt
+          updated: out/comment.txt
+        text: |
+          Original comment:
+          $original
+          
+          new comment:
+          $updated
 ```
diff --git a/scripts/in b/scripts/in
index 8fe0fd6..4744f06 100755
--- a/scripts/in
+++ b/scripts/in
@@ -12,7 +12,7 @@ source "$(dirname "$0")/common.sh"
 
 destination="$1"
 
-if [ -z "${destination}" ]; then
+if [[ -z "${destination}" ]]; then
     echo "Usage: $0 <path/to/destination>" >&2
     exit 1
 fi
diff --git a/scripts/out b/scripts/out
index 227ec5f..2e74f1c 100755
--- a/scripts/out
+++ b/scripts/out
@@ -12,7 +12,7 @@ source "$(dirname "$0")/common.sh"
 
 destination="$1"
 
-if [ -z "${destination}" ]; then
+if [[ -z "${destination}" ]]; then
     echo "Usage: $0 <path/to/destination>" >&2
     exit 1
 fi
@@ -27,16 +27,19 @@ uri="$(jq -r '.source.uri // ""' < "${payload}")"
 private_token="$(jq -r '.source.private_token // ""' < "${payload}")"
 private_key="$(jq -r '.source.private_key // ""' < "${payload}")"
 no_ssl="$(jq -r '.source.no_ssl // ""' < "${payload}")"
-params="$(jq -r '.params // ""' < "${payload}")"
-path_to_repo="$(echo "${params}" | jq -r '.repository // ""')"
-new_status="$(echo "${params}" | jq -r '.status // ""')"
-build_label="$(echo "${params}" | jq -r '.build_label // "Concourse"')"
-
-if [ -z "${path_to_repo}" ]; then
+path_to_repo="$(jq -c -r '.params.repository // ""' < "${payload}")"
+new_status="$(jq -c -r '.params.status // ""' < "${payload}")"
+build_label="$(jq -c -r '.params.build_label // "Concourse"' < "${payload}")"
+comment_text="$(jq -c -r '.params.comment.text // ""' < "${payload}")"
+comment_file="$(jq -c -r '.params.comment.file // ""' < "${payload}")"
+comment_files="$(jq -c -r '.params.comment.files // ""' < "${payload}")"
+comment=""
+
+if [[ -z "${path_to_repo}" ]]; then
     echo "please specify a repository" >&2
     exit 1
 fi
-if [ -z "${new_status}" ]; then
+if [[ -z "${new_status}" ]]; then
     echo "please specify a status" >&2
     exit 1
 fi
@@ -54,13 +57,39 @@ else
     project_path="$(echo "${uri}" | sed -rn 's/(https?):\/\/([^\/]*)\/(.*)\.git/\3/p')"
     protocol="$(echo "${uri}" | sed -rn 's/(https?):\/\/([^\/]*)\/(.*)\.git/\1/p')"
 fi
-if [ "${no_ssl}" == 'true' ]; then
+if [[ "${no_ssl}" == 'true' ]]; then
     protocol='http'
 fi
 
 target_url="${ATC_EXTERNAL_URL}/teams/$(urlencode "${BUILD_TEAM_NAME}")/pipelines/$(urlencode "${BUILD_PIPELINE_NAME}")/jobs/$(urlencode "${BUILD_JOB_NAME}")/builds/$(urlencode "${BUILD_NAME}")"
 
 cd "${destination}"
+
+if [[ (-z "${comment_files}") && (! -z "${comment_file}") ]]; then
+    comment_files=$(echo "${comment_file}" | jq -c --raw-input '{ "FILE_CONTENT": . }')
+fi
+
+if [[ (! -z "${comment_text}") ]]; then
+    comment=$(echo "${comment_text}" | sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/<br\/>/g')
+
+    if [[ ! -z "${comment_files}" ]]; then
+        for row in $(echo "${comment_files}" | jq -c -r 'to_entries[] | @base64'); do
+            _jq() {
+                 echo ${row} | base64 -d | jq -r ${1}
+            }
+
+            file_key=$(echo "\$$(_jq '.key')" | sed -e 's/[]\/$*.^[]/\\&/g')
+            file_name=$(_jq '.value')
+            if [ -f "${file_name}" ]; then
+              file_content=$(cat  | sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/<br\/>/g' -e 's/[\/&]/\\&/g' "${file_name}")
+              comment=$(echo "${comment}" | sed "s/${file_key}/${file_content}/g")
+            fi
+        done
+    fi
+elif [[ (! -z "${comment_file}") ]]; then
+    comment=$(cat "${comment_file}")
+fi
+
 cd "${path_to_repo}"
 
 commit_sha="$(git rev-parse HEAD)"
@@ -72,6 +101,24 @@ curl \
     --data "{\"state\":\"${new_status}\",\"name\":\"${build_label}\",\"target_url\":\"${target_url}\"}" \
     "${protocol}://${gitlab_host}/api/v4/projects/$(urlencode "${project_path}")/statuses/${commit_sha}"
 
+if [[ (! -z "${private_key}") && (! -z "${comment}") ]]; then
+    git_branch=$(git show-ref --heads | sed -n "s/^$(git rev-parse HEAD) refs\/heads\/\(.*\)/\1/p")
+    merge_requests=$(curl \
+        --request GET \
+        --header "PRIVATE-TOKEN: ${private_token}" \
+        "${protocol}://${gitlab_host}/api/v4/projects/$(urlencode "${project_path}")/merge_requests?source_branch=${git_branch}")
+
+    for merge_request_id in $(echo "${merge_requests}" | jq -r '.[].iid'); do
+        # Post comment to each merge request
+        curl \
+            --request POST \
+            --data "$(echo "${comment}" | jq -c -R '{ "body": . }')" \
+            --header "Content-Type: application/json" \
+            --header "PRIVATE-TOKEN: ${private_token}" \
+            "${protocol}://${gitlab_host}/api/v4/projects/$(urlencode "${project_path}")/merge_requests/$(urlencode "${merge_request_id}")/notes"
+    done
+fi
+
 version="{\"sha\":\"${commit_sha}\"}"
 
 jq -n "{