fix/change headername/alt

crates/common/README.md

@@ -51,8 +51,8 @@ Behavior is covered by an extensive test suite in `crates/common/src/creative.rs
 
 - `synthetic.rs` generates a deterministic synthetic identifier per user request and exposes helpers:
   - `generate_synthetic_id` — creates a fresh HMAC-based ID using request signals.
-  - `get_synthetic_id` — extracts an existing ID from the `X-Synthetic-Trusted-Server` header or `synthetic_id` cookie.
+  - `get_synthetic_id` — extracts an existing ID from the `x-psid-ts` header or `synthetic_id` cookie.
   - `get_or_generate_synthetic_id` — reuses the existing ID when present, otherwise creates one.
-- `publisher.rs::handle_publisher_request` stamps proxied origin responses with `X-Synthetic-Fresh`, `X-Synthetic-Trusted-Server`, and (when absent) issues the `synthetic_id` cookie so the browser keeps the identifier on subsequent requests.
+- `publisher.rs::handle_publisher_request` stamps proxied origin responses with `X-Synthetic-Fresh`, `x-psid-ts`, and (when absent) issues the `synthetic_id` cookie so the browser keeps the identifier on subsequent requests.
 - `proxy.rs::handle_first_party_proxy` replays the identifier to third-party creative origins by appending `synthetic_id=<value>` to the reconstructed target URL, follows redirects (301/302/303/307/308) up to four hops, and keeps downstream fetches linked to the same user scope.
 - `proxy.rs::handle_first_party_click` adds `synthetic_id=<value>` to outbound click redirect URLs so analytics endpoints can associate clicks with impressions without third-party cookies.

crates/common/build.rs

@@ -14,6 +14,7 @@ const TRUSTED_SERVER_OUTPUT_CONFIG_PATH: &str = "../../target/trusted-server-out
 
 fn main() {
     merge_toml();
+    generate_header_constants();
     rerun_if_changed();
 }
 
@@ -57,6 +58,37 @@ fn merge_toml() {
     fs::write(dest_path, merged_toml).unwrap_or_else(|_| panic!("Failed to write {:?}", dest_path));
 }
 
+fn generate_header_constants() {
+    // Read and parse the config
+    let init_config_path = Path::new(TRUSTED_SERVER_INIT_CONFIG_PATH);
+    let toml_content = fs::read_to_string(init_config_path)
+        .unwrap_or_else(|_| panic!("Failed to read {:?}", init_config_path));
+
+    let settings = settings::Settings::from_toml(&toml_content)
+        .expect("Failed to parse settings at build time");
+
+    // Generate the header name based on psid
+    let psid = &settings.publisher.psid;
+    let header_name = format!("x-{}-ts", psid);
+
+    // Generate Rust code for the constant
+    let generated_code = format!(
+        r#"// This file is auto-generated by build.rs - DO NOT EDIT
+
+pub const HEADER_SYNTHETIC_TRUSTED_SERVER: HeaderName = HeaderName::from_static("{}");
+"#,
+        header_name
+    );
+
+    // Write to OUT_DIR
+    let out_dir = std::env::var("OUT_DIR").expect("OUT_DIR not set");
+    let dest_path = Path::new(&out_dir).join("generated_header_constants.rs");
+    fs::write(&dest_path, generated_code)
+        .unwrap_or_else(|_| panic!("Failed to write {:?}", dest_path));
+
+    println!("cargo:warning=Generated header constant: {}", header_name);
+}
+
 fn collect_env_vars(value: &Value, env_vars: &mut HashSet<String>, path: Vec<String>) {
     if let Value::Object(map) = value {
         for (key, val) in map {

crates/common/src/constants.rs

@@ -3,8 +3,9 @@ use http::header::HeaderName;
 pub const HEADER_SYNTHETIC_FRESH: HeaderName = HeaderName::from_static("x-synthetic-fresh");
 pub const HEADER_SYNTHETIC_PUB_USER_ID: HeaderName = HeaderName::from_static("x-pub-user-id");
 pub const HEADER_X_PUB_USER_ID: HeaderName = HeaderName::from_static("x-pub-user-id");
-pub const HEADER_SYNTHETIC_TRUSTED_SERVER: HeaderName =
-    HeaderName::from_static("x-synthetic-trusted-server");
+
+// Generated at build time from publisher.id_prefix in trusted-server.toml
+include!(concat!(env!("OUT_DIR"), "/generated_header_constants.rs"));
 pub const HEADER_X_CONSENT_ADVERTISING: HeaderName =
     HeaderName::from_static("x-consent-advertising");
 pub const HEADER_X_FORWARDED_FOR: HeaderName = HeaderName::from_static("x-forwarded-for");

crates/common/src/gam.rs

@@ -6,6 +6,7 @@ use std::collections::HashMap;
 use std::io::Read;
 use uuid::Uuid;
 
+use crate::constants::HEADER_SYNTHETIC_TRUSTED_SERVER;
 use crate::error::TrustedServerError;
 use crate::gdpr::get_consent_from_request;
 use crate::settings::Settings;
@@ -35,7 +36,7 @@ impl GamRequest {
 
         // Get synthetic ID from request headers
         let synthetic_id = req
-            .get_header("X-Synthetic-Trusted-Server")
+            .get_header(HEADER_SYNTHETIC_TRUSTED_SERVER)
             .and_then(|h| h.to_str().ok())
             .unwrap_or("unknown")
             .to_string();
@@ -1077,12 +1078,14 @@ mod tests {
     use super::*;
     use serde_json::json;
 
-    use crate::test_support::tests::create_test_settings;
+    use crate::{
+        constants::HEADER_SYNTHETIC_TRUSTED_SERVER, test_support::tests::create_test_settings,
+    };
 
     fn create_test_request() -> Request {
         let mut req = Request::new(Method::GET, "https://example.com/test");
         req.set_header(header::USER_AGENT, "Mozilla/5.0 Test Browser");
-        req.set_header("X-Synthetic-Trusted-Server", "test-synthetic-id-123");
+        req.set_header(HEADER_SYNTHETIC_TRUSTED_SERVER, "test-synthetic-id-123");
         req
     }
 
@@ -1171,7 +1174,7 @@ mod tests {
             Method::GET,
             "https://example.com/test?param=value&special=test%20space",
         );
-        req.set_header("X-Synthetic-Trusted-Server", "test-id");
+        req.set_header(HEADER_SYNTHETIC_TRUSTED_SERVER, "test-id");
 
         let gam_req = GamRequest::new(&settings, &req).unwrap();
         let url = gam_req.build_golden_url();
@@ -1215,7 +1218,7 @@ mod tests {
         let settings = create_test_settings();
         let mut req = Request::new(Method::GET, "https://example.com/gam-test");
         req.set_header("X-Consent-Advertising", "true");
-        req.set_header("X-Synthetic-Trusted-Server", "test-synthetic-id");
+        req.set_header(HEADER_SYNTHETIC_TRUSTED_SERVER, "test-synthetic-id");
 
         // Note: This test will fail when actually sending to GAM backend
         // In a real test environment, we'd mock the backend response

crates/common/src/publisher.rs

@@ -126,7 +126,7 @@ pub fn handle_main_page(
     let fresh_id = generate_synthetic_id(settings, &req)?;
 
     // Check for existing Trusted Server ID in this specific order:
-    // 1. X-Synthetic-Trusted-Server header
+    // 1. x-psid-ts header
     // 2. Cookie
     // 3. Fall back to fresh ID
     let synthetic_id = get_or_generate_synthetic_id(settings, &req)?;

crates/common/src/settings.rs

@@ -25,6 +25,14 @@
     /// Secret used to encrypt/decrypt proxied URLs in `/first-party/proxy`.
     /// Keep this secret stable to allow existing links to decode.
     pub proxy_secret: String,
+    /// Prefix for the publisher-specific ID header (x-{psid}-ts).
+    /// Defaults to "psid" if not specified.
+    #[serde(default = "default_psid")]
+    pub psid: String,
+}
+
+fn default_psid() -> String {
+    "psid".to_string()
 }
 
 impl Publisher {
@@ -35,7 +43,7 @@
     /// ```
     /// # use trusted_server_common::settings::Publisher;
     /// let publisher = Publisher {
     ///     domain: "example.com".to_string(),
     ///     cookie_domain: ".example.com".to_string(),
     ///     origin_url: "https://origin.example.com:8080".to_string(),
     ///     proxy_secret: "proxy-secret".to_string(),
@@ -530,6 +538,7 @@
             cookie_domain: ".example.com".to_string(),
             origin_url: "https://origin.example.com:8080".to_string(),
             proxy_secret: "test-secret".to_string(),
+            psid: "psid".to_string(),
         };
         assert_eq!(publisher.origin_host(), "origin.example.com:8080");
 
@@ -539,6 +548,7 @@
             cookie_domain: ".example.com".to_string(),
             origin_url: "https://origin.example.com".to_string(),
             proxy_secret: "test-secret".to_string(),
+            psid: "psid".to_string(),
         };
         assert_eq!(publisher.origin_host(), "origin.example.com");
 
@@ -548,6 +558,7 @@
             cookie_domain: ".example.com".to_string(),
             origin_url: "http://localhost:9090".to_string(),
             proxy_secret: "test-secret".to_string(),
+            psid: "psid".to_string(),
         };
         assert_eq!(publisher.origin_host(), "localhost:9090");
 
@@ -557,6 +568,7 @@
             cookie_domain: ".example.com".to_string(),
             origin_url: "localhost:9090".to_string(),
             proxy_secret: "test-secret".to_string(),
+            psid: "psid".to_string(),
         };
         assert_eq!(publisher.origin_host(), "localhost:9090");
 
@@ -566,6 +578,7 @@
             cookie_domain: ".example.com".to_string(),
             origin_url: "http://192.168.1.1:8080".to_string(),
             proxy_secret: "test-secret".to_string(),
+            psid: "psid".to_string(),
         };
         assert_eq!(publisher.origin_host(), "192.168.1.1:8080");
 
@@ -575,6 +588,7 @@
             cookie_domain: ".example.com".to_string(),
             origin_url: "http://[::1]:8080".to_string(),
             proxy_secret: "test-secret".to_string(),
+            psid: "psid".to_string(),
         };
         assert_eq!(publisher.origin_host(), "[::1]:8080");
     }

crates/common/src/synthetic.rs

@@ -83,7 +83,7 @@ pub fn generate_synthetic_id(
 /// Gets or creates a synthetic ID from the request.
 ///
 /// Attempts to retrieve an existing synthetic ID from:
-/// 1. The `X-Synthetic-Trusted-Server` header
+/// 1. The `x-psid-ts` header
 /// 2. The `synthetic_id` cookie
 ///
 /// If neither exists, generates a new synthetic ID.

crates/common/src/templates.rs

@@ -1208,7 +1208,7 @@ pub const GAM_TEST_TEMPLATE: &str = r#"
             try {
                 const response = await fetch('/');
                 const freshId = response.headers.get('X-Synthetic-Fresh');
-                const trustedServerId = response.headers.get('X-Synthetic-Trusted-Server');
+                const trustedServerId = response.headers.get('x-psid-ts');
 
                 const statusDiv = document.getElementById('syntheticStatus');
                 statusDiv.className = 'status success';
@@ -1280,14 +1280,14 @@ pub const GAM_TEST_TEMPLATE: &str = r#"
                 // First get the main page to ensure we have synthetic IDs
                 const mainResponse = await fetch('/');
                 const freshId = mainResponse.headers.get('X-Synthetic-Fresh');
-                const trustedServerId = mainResponse.headers.get('X-Synthetic-Trusted-Server');
+                const trustedServerId = mainResponse.headers.get('x-psid-ts');
 
                 // Now test the GAM request
                 const response = await fetch('/gam-test', {
                     headers: {
                         'X-Consent-Advertising': 'true',
                         'X-Synthetic-Fresh': freshId || '',
-                        'X-Synthetic-Trusted-Server': trustedServerId || ''
+                        'x-psid-ts': trustedServerId || ''
                     }
                 });
 

crates/js/README.md

@@ -111,7 +111,7 @@ The Rust services (`trusted-server-common`) expose several proxy entry points th
 
 - Endpoint: `handle_publisher_request` (`crates/common/src/publisher.rs`).
 - Retrieves or generates the trusted synthetic identifier before Fastly consumes the request body.
-- Always stamps the proxied response with `X-Synthetic-Fresh` and `X-Synthetic-Trusted-Server` headers and, when the browser does not already present one, sets the `synthetic_id=<value>` cookie (Secure + SameSite=Lax) bound to the configured publisher domain.
+- Always stamps the proxied response with `X-Synthetic-Fresh` and `x-psid-ts` headers and, when the browser does not already present one, sets the `synthetic_id=<value>` cookie (Secure + SameSite=Lax) bound to the configured publisher domain.
 - Result: downstream assets fetched through the same first-party origin automatically include the synthetic ID header/cookie so subsequent proxy layers can read it.
 
 ### Creative Asset Proxy

trusted-server.toml

@@ -7,6 +7,7 @@ domain = "test-publisher.com"
 cookie_domain = ".test-publisher.com"
 origin_url = "https://origin.test-publisher.com"
 proxy_secret = "change-me-proxy-secret"
+psid = "psid"
 
 [prebid]
 server_url = "http://68.183.113.79:8000"