diff --git a/README.md b/README.md
index 04f6d4e..566b6ca 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,9 @@ If you have an existing `fly.toml` in your repo, this action will copy it with a
 | `path`     | Path to run the `flyctl` commands from. Useful if you have an existing `fly.toml` in a subdirectory.                                                                                                     |
 | `postgres` | Optional name of an existing Postgres cluster to `flyctl postgres attach` to.                                                                                                                            |
 | `update`   | Whether or not to update this Fly app when the PR is updated. Default `true`.                                                                                                                            |
-| `secrets`  | Secrets to be set on the app. Separate multiple secrets with a space                                                                                                                                     |
+| `secrets`  | Secrets to be set on the app at runtime. Separate multiple secrets with a space                                                                                                                                     |
+| build_args | Optional Docker --build-arg |
+| build_secrets | Optional Docker --build-secret |
 | `vmsize`   | Set app VM to a named size, eg. shared-cpu-1x, dedicated-cpu-1x, dedicated-cpu-2x etc. Takes precedence over cpu, cpu kind, and memory inputs.                                                           |
 | `cpu`      | Set app VM CPU (defaults to 1 cpu). Default 1.                                                                                                                                                           |
 | `cpukind`  | Set app VM CPU kind - shared or performance. Default shared.                                                                                                                                             |
diff --git a/action.yml b/action.yml
index 0748d75..20d1d18 100644
--- a/action.yml
+++ b/action.yml
@@ -14,6 +14,10 @@ inputs:
     description: Optional pre-existing Docker image to use
   config:
     description: Optional path to a custom Fly toml config. Config path should be relative to `path` parameter, if specified.
+  build_args:
+    description: Optional Docker --build-arg
+  build_secrets:
+    description: Optional Docker --build-secret
   region:
     description: Region to launch the app in (alternatively, set the env FLY_REGION)
   org:
@@ -23,7 +27,7 @@ inputs:
   postgres:
     description: Optionally attach the app to a pre-existing Postgres cluster on Fly
   secrets:
-    description: Secrets to be set on the app. Separate multiple secrets with a space
+    description: Secrets to be set on the app at runtime. Separate multiple secrets with a space
   vmsize:
     description: Set app VM to a named size, eg. shared-cpu-1x, dedicated-cpu-1x, dedicated-cpu-2x etc. Takes precedence over cpu, cpu kind, and memory inputs.
   cpu:
diff --git a/entrypoint.sh b/entrypoint.sh
index 1ec9f5c..2b0b3b9 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -24,6 +24,8 @@ region="${INPUT_REGION:-${FLY_REGION:-iad}}"
 org="${INPUT_ORG:-${FLY_ORG:-personal}}"
 image="$INPUT_IMAGE"
 config="${INPUT_CONFIG:-fly.toml}"
+build_args=""
+build_secrets=""
 
 if ! echo "$app" | grep "$PR_NUMBER"; then
   echo "For safety, this action requires the app's name to contain the PR number."
@@ -36,14 +38,27 @@ if [ "$EVENT_TYPE" = "closed" ]; then
   exit 0
 fi
 
+if [ -n "$INPUT_BUILD_ARGS" ]; then
+  for ARG in $(echo "$INPUT_BUILD_ARGS" | tr " " "\n"); do
+    build_args="$build_args --build-arg ${ARG}"
+  done
+fi
+
+if [ -n "$INPUT_BUILD_SECRETS" ]; then
+  for ARG in $(echo "$INPUT_BUILD_SECRETS" | tr " " "\n"); do
+    build_secrets="$build_secrets --build-secret ${ARG}"
+  done
+fi
+
 # Deploy the Fly app, creating it first if needed.
 if ! flyctl status --app "$app"; then
   # Backup the original config file since 'flyctl launch' messes up the [build.args] section
   cp "$config" "$config.bak"
-  flyctl launch --no-deploy --copy-config --name "$app" --image "$image" --region "$region" --org "$org"
+  flyctl launch --no-deploy --copy-config --name "$app" --image "$image" --region "$region" --org "$org" ${build_args} ${build_secrets}
   # Restore the original config file
   cp "$config.bak" "$config"
 fi
+
 if [ -n "$INPUT_SECRETS" ]; then
   echo $INPUT_SECRETS | tr " " "\n" | flyctl secrets import --app "$app"
 fi
@@ -56,9 +71,9 @@ fi
 # Trigger the deploy of the new version.
 echo "Contents of config $config file: " && cat "$config"
 if [ -n "$INPUT_VM" ]; then
-  flyctl deploy --config "$config" --app "$app" --region "$region" --image "$image" --strategy immediate --ha=$INPUT_HA --vm-size "$INPUT_VMSIZE"
+  flyctl deploy --config "$config" --app "$app" --region "$region" --image "$image" --strategy immediate --ha=$INPUT_HA ${build_args} ${build_secrets} --vm-size "$INPUT_VMSIZE"
 else
-  flyctl deploy --config "$config" --app "$app" --region "$region" --image "$image" --strategy immediate --ha=$INPUT_HA --vm-cpu-kind "$INPUT_CPUKIND" --vm-cpus $INPUT_CPU --vm-memory "$INPUT_MEMORY"
+  flyctl deploy --config "$config" --app "$app" --region "$region" --image "$image" --strategy immediate --ha=$INPUT_HA ${build_args} ${build_secrets} --vm-cpu-kind "$INPUT_CPUKIND" --vm-cpus $INPUT_CPU --vm-memory "$INPUT_MEMORY"
 fi
 
 # Make some info available to the GitHub workflow.