Change x-synthetic-trusted-server header to x-psid-ts

Author: ChristianPavilonis

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/src/constants.rs

@@ -4,7 +4,7 @@ pub const HEADER_SYNTHETIC_FRESH: HeaderName = HeaderName::from_static("x-synthe
 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");
+    HeaderName::from_static("x-psid-ts");
 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 +1078,12 @@ 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 +1172,7 @@ 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 +1216,7 @@ 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/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