diff --git a/README.md b/README.md
index d4f6d95..e7fd985 100644
--- a/README.md
+++ b/README.md
@@ -47,8 +47,9 @@ EPSILON = "0.1" # Privacy budget parameter for obfuscating the counts in the str
 ROUNDING_STEP = "10" # The granularity of the rounding of the obfuscated values, has no effect if OBFUSCATE = "no", default value: 10
 PROJECTS_NO_OBFUSCATION = "exliquid;dktk_supervisors" # Projects for which the results are not to be obfuscated, separated by ;, default value: "exliquid; dktk_supervisors"
 QUERIES_TO_CACHE_FILE_PATH = "resources/bbmri" # The path to the file containing BASE64 encoded queries whose results are to be cached, if not set, no results are cached
-PROVIDER = "" #OMOP provider name
-PROVIDER_ICON = "" #Base64 encoded OMOP provider icon
+PROVIDER = "name" #OMOP provider name
+PROVIDER_ICON = "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEUAAACnej3aAAAAAXRSTlMAQObYZgAAAApJREFUCNdjYAAAAAIAAeIhvDMAAAAASUVORK5CYII=" #Base64 encoded OMOP provider icon
+AUTH_HEADER = "ApiKey XXXX" #Authorization header
 ```
 
 Obfuscating zero counts is by default switched off. To enable obfuscating zero counts, set the env. variable `OBFUSCATE_ZERO`. 
diff --git a/src/config.rs b/src/config.rs
index f2c1458..b02cfe7 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -130,13 +130,17 @@ struct CliArgs {
     tls_ca_certificates_dir: Option<PathBuf>,
 
     /// OMOP provider name
-    #[clap(long, env, value_parser, default_value = "")]
+    #[clap(long, env, value_parser)]
     provider: Option<String>,
   
     /// Base64 encoded OMOP provider icon
-    #[clap(long, env, value_parser, default_value = "")]
+    #[clap(long, env, value_parser)]
     provider_icon: Option<String>,
 
+    /// Authorization header
+    #[clap(long, env, value_parser)]
+    auth_header: Option<String>,
+
 }
 
 pub(crate) struct Config {
@@ -162,6 +166,7 @@ pub(crate) struct Config {
     pub client: Client,
     pub provider: Option<String>,
     pub provider_icon: Option<String>,
+    pub auth_header: Option<String>,
 }
 
 impl Config {
@@ -199,6 +204,7 @@ impl Config {
             tls_ca_certificates,
             provider: cli_args.provider,
             provider_icon: cli_args.provider_icon,
+            auth_header: cli_args.auth_header,
             client,
         };
         Ok(config)
diff --git a/src/errors.rs b/src/errors.rs
index a11f00d..6888210 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -46,4 +46,7 @@ pub enum FocusError {
     AstOperatorValueMismatch(),
     #[error("Invalid date format: {0}")]
     AstInvalidDateFormat(String),
+    #[error("Invalid Header Value: {0}")]
+    InvalidHeaderValue(http::header::InvalidHeaderValue),
+
 }
diff --git a/src/omop.rs b/src/omop.rs
index e87a579..283f9a3 100644
--- a/src/omop.rs
+++ b/src/omop.rs
@@ -1,4 +1,7 @@
+use http::HeaderMap;
+use http::HeaderValue;
 use http::StatusCode;
+use http::header;
 use serde::Deserialize;
 use serde::Serialize;
 use tracing::{debug, warn};
@@ -24,10 +27,26 @@ pub async fn post_ast(ast: ast::Ast) -> Result<String, FocusError> {
 
     debug!("{}", ast_string.clone());
 
+    let mut headers = HeaderMap::new();
+
+    headers.insert(header::CONTENT_TYPE, 
+        HeaderValue::from_str("application/json")
+        .map_err(|e| FocusError::InvalidHeaderValue(e))?);
+   
+    match CONFIG.auth_header.clone() {
+        Some(auth_header_value) => {
+            headers.insert(header::AUTHORIZATION, 
+                HeaderValue::from_str(auth_header_value.as_str())
+                .map_err(|e| FocusError::InvalidHeaderValue(e))?);
+        },
+
+        None => {}
+    }
+        
     let resp = CONFIG
         .client
         .post(format!("{}", CONFIG.endpoint_url))
-        .header("Content-Type", "application/json")
+        .headers(headers)
         .body(ast_string.clone())
         .send()
         .await