Pass user agent to auction telemetry

crates/trusted-server-adapter-fastly/src/tinybird.rs

@@ -238,6 +238,9 @@ mod tests {
 
     use super::*;
 
+    const TEST_USER_AGENT: &str =
+        "FictionalBrowser/123.4 (FictionalOS 10.2; FictionalDevice) ExampleRenderer/567.8";
+
     struct NoopConfigStore;
 
     impl PlatformConfigStore for NoopConfigStore {
@@ -399,6 +402,7 @@ mod tests {
             region: None,
             is_mobile: 0,
             is_known_browser: 1,
+            user_agent: Some(TEST_USER_AGENT.to_owned()),
             gdpr_applies: 0,
             consent_present: 0,
             terminal_status: Some("completed".to_owned()),
@@ -523,11 +527,11 @@ mod tests {
             header_value(&requests[0].headers, header::AUTHORIZATION.as_str()),
             Some("Bearer append-token")
         );
+        let body = std::str::from_utf8(&requests[0].body).expect("should record utf8 ndjson body");
+        assert!(body.ends_with('\n'), "should send newline-delimited JSON");
         assert!(
-            std::str::from_utf8(&requests[0].body)
-                .expect("should record utf8 ndjson body")
-                .ends_with('\n'),
-            "should send newline-delimited JSON"
+            body.contains(TEST_USER_AGENT),
+            "should send the complete user agent to Tinybird"
         );
         assert_eq!(
             *http_client

crates/trusted-server-core/src/auction/telemetry.rs

@@ -1,7 +1,7 @@
 //! Auction telemetry row construction and sink abstraction.
 //!
-//! Core owns the privacy-preserving auction observation model and pure row
-//! builder. Platform adapters provide the concrete sink implementation.
+//! Core owns the auction observation model and pure row builder. Platform
+//! adapters provide the concrete sink implementation.
 
 use std::collections::HashSet;
 use std::time::Instant;
@@ -19,6 +19,9 @@ use crate::platform::RuntimeServices;
 
 const MAX_PAGE_PATH_BYTES: usize = 256;
 const DYNAMIC_SEGMENT_REPLACEMENT: &str = ":id";
+#[cfg(test)]
+const TEST_USER_AGENT: &str =
+    "FictionalBrowser/123.4 (FictionalOS 10.2; FictionalDevice) ExampleRenderer/567.8";
 
 /// Source path that initiated an auction candidate.
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
@@ -91,7 +94,7 @@ impl AbandonedProviderCall {
     }
 }
 
-/// Privacy-preserving context shared by all rows in one auction observation.
+/// Context shared by all rows in one auction observation.
 #[derive(Debug, Clone)]
 pub struct AuctionObservationContext {
     /// Fresh telemetry UUID, independent of EC and internal auction IDs.
@@ -110,6 +113,8 @@ pub struct AuctionObservationContext {
     pub is_mobile: u8,
     /// `0` = bot, `1` = browser, `2` = unknown.
     pub is_known_browser: u8,
+    /// Complete User-Agent supplied by the auction request, when present.
+    pub user_agent: Option<String>,
     /// Whether GDPR applies.
     pub gdpr_applies: bool,
     /// Whether any consent signal was present.
@@ -134,11 +139,16 @@ impl AuctionObservationContext {
             .and_then(|page_url| url::Url::parse(page_url).ok())
             .map(|url| url.path().to_owned())
             .unwrap_or_else(|| "/".to_owned());
+        let user_agent = request
+            .device
+            .as_ref()
+            .and_then(|device| device.user_agent.as_deref());
         Self::from_parts(
             auction_source,
             &request.publisher.domain,
             &raw_path,
             request.slots.len(),
+            user_agent,
             ec_context,
         )
     }
@@ -150,6 +160,7 @@ impl AuctionObservationContext {
         publisher_domain: &str,
         raw_page_path: &str,
         slot_count: usize,
+        user_agent: Option<&str>,
         ec_context: &EcContext,
     ) -> Self {
         let device = ec_context.device_signals();
@@ -172,6 +183,7 @@ impl AuctionObservationContext {
                 Some(false) => 0,
                 None => 2,
             },
+            user_agent: user_agent.map(str::to_owned),
             gdpr_applies: consent.gdpr_applies,
             consent_present: !consent.is_empty(),
             slot_count,
@@ -196,6 +208,7 @@ impl AuctionObservationContext {
             region: Some("CA".to_owned()),
             is_mobile: 0,
             is_known_browser: 1,
+            user_agent: Some(TEST_USER_AGENT.to_owned()),
             gdpr_applies: false,
             consent_present: false,
             slot_count,
@@ -282,6 +295,8 @@ pub struct AuctionEventRow {
     pub is_mobile: u8,
     /// `0` = bot, `1` = browser, `2` = unknown.
     pub is_known_browser: u8,
+    /// Complete User-Agent supplied by the auction request, when present.
+    pub user_agent: Option<String>,
     /// `0` or `1`.
     pub gdpr_applies: u8,
     /// `0` or `1`.
@@ -341,6 +356,7 @@ impl AuctionEventRow {
             region: observation.region.clone(),
             is_mobile: observation.is_mobile,
             is_known_browser: observation.is_known_browser,
+            user_agent: observation.user_agent.clone(),
             gdpr_applies: u8::from(observation.gdpr_applies),
             consent_present: u8::from(observation.consent_present),
             terminal_status: None,
@@ -933,7 +949,7 @@ mod tests {
 
     use serde_json::json;
 
-    use crate::auction::types::{AdFormat, AdSlot, PublisherInfo, UserInfo};
+    use crate::auction::types::{AdFormat, AdSlot, DeviceInfo, PublisherInfo, UserInfo};
 
     use super::*;
 
@@ -1005,6 +1021,52 @@ mod tests {
         );
     }
 
+    #[test]
+    fn observation_sources_preserve_complete_user_agent() {
+        let ec_context =
+            EcContext::new_for_test(None, crate::consent::types::ConsentContext::default());
+        let mut request = test_request("request-id");
+        request.device = Some(DeviceInfo {
+            user_agent: Some(TEST_USER_AGENT.to_owned()),
+            ip: None,
+            geo: None,
+        });
+
+        let from_request = AuctionObservationContext::from_auction_request(
+            AuctionSource::AuctionApi,
+            &request,
+            &ec_context,
+        );
+        let from_parts = AuctionObservationContext::from_parts(
+            AuctionSource::InitialNavigation,
+            "test-publisher.example",
+            "/article",
+            1,
+            Some(TEST_USER_AGENT),
+            &ec_context,
+        );
+        let without_user_agent = AuctionObservationContext::from_auction_request(
+            AuctionSource::AuctionApi,
+            &test_request("request-without-user-agent"),
+            &ec_context,
+        );
+
+        assert_eq!(
+            from_request.user_agent.as_deref(),
+            Some(TEST_USER_AGENT),
+            "should preserve the complete user agent from an auction request"
+        );
+        assert_eq!(
+            from_parts.user_agent.as_deref(),
+            Some(TEST_USER_AGENT),
+            "should preserve the complete user agent from publisher request parts"
+        );
+        assert_eq!(
+            without_user_agent.user_agent, None,
+            "should omit a missing user agent"
+        );
+    }
+
     #[test]
     fn normalize_page_path_strips_query_and_redacts_dynamic_segments() {
         assert_eq!(
@@ -1065,6 +1127,11 @@ mod tests {
         );
 
         let rows = batch.rows();
+        assert!(
+            rows.iter()
+                .all(|row| row.user_agent.as_deref() == Some(TEST_USER_AGENT)),
+            "should copy the complete user agent to every row kind"
+        );
         assert_eq!(
             rows.iter()
                 .filter(|row| row.event_kind == "summary")
@@ -1249,6 +1316,10 @@ mod tests {
         .expect("should serialize ndjson");
 
         assert!(body.ends_with('\n'), "should end each row with newline");
+        assert!(
+            body.contains(TEST_USER_AGENT),
+            "should preserve the complete user agent in serialized rows"
+        );
         for line in body.lines() {
             let parsed: serde_json::Value = serde_json::from_str(line).expect("should parse row");
             assert_eq!(parsed["event_kind"], "summary");

crates/trusted-server-core/src/publisher.rs

@@ -4214,11 +4214,16 @@ pub async fn handle_publisher_request(
         // trusted-server edge host, so using it here would attribute navigation
         // rows to the edge/staging domain while `/auction` rows (built from
         // `AuctionRequest::publisher.domain`) use the configured domain.
+        let user_agent = req
+            .headers()
+            .get("user-agent")
+            .and_then(|value| value.to_str().ok());
         let observation = AuctionObservationContext::from_parts(
             AuctionSource::InitialNavigation,
             &settings.publisher.domain,
             &request_path,
             matched_slots.len(),
+            user_agent,
             ec_context,
         );
 
@@ -4233,9 +4238,7 @@ pub async fn handle_publisher_request(
                 &consent_context,
                 &request_info,
                 &settings.publisher.domain,
-                req.headers()
-                    .get("user-agent")
-                    .and_then(|v| v.to_str().ok()),
+                user_agent,
             );
             apply_auction_eids_and_device(
                 &mut auction_request,
@@ -6453,11 +6456,16 @@ pub async fn handle_page_bids(
     } else {
         // Same publisher identity as the outbound bid request — see the
         // matching note on the initial-navigation observation above.
+        let user_agent = req
+            .headers()
+            .get("user-agent")
+            .and_then(|value| value.to_str().ok());
         let observation = AuctionObservationContext::from_parts(
             AuctionSource::SpaNavigation,
             &settings.publisher.domain,
             &path_param,
             matched_slots.len(),
+            user_agent,
             ec_context,
         );
         if ad_stack_enabled && !is_bot && !is_prefetch {
@@ -6471,9 +6479,7 @@ pub async fn handle_page_bids(
                 consent_context,
                 &request_info,
                 &settings.publisher.domain,
-                req.headers()
-                    .get("user-agent")
-                    .and_then(|v| v.to_str().ok()),
+                user_agent,
             );
             apply_auction_eids_and_device(
                 &mut auction_request,
@@ -17031,6 +17037,7 @@ mod tests {
                     "proxy.example.com",
                     "/article",
                     1,
+                    Some("FictionalBrowser/123.4"),
                     &ec_context,
                 )),
                 auction_request: Some(test_auction_request()),

docs/superpowers/plans/2026-06-23-auction-telemetry-direct-tinybird.md

@@ -34,7 +34,8 @@ The implementation must:
 - cover `POST /auction`, `GET /__ts/page-bids`, and initial-navigation SSAT dispatch/collect;
 - emit exactly one summary row per auction candidate per successful Compute execution path;
 - batch all rows for one auction observation into one Tinybird Events API POST;
-- omit EC ID, internal `AuctionRequest.id`, IP, raw user agent, full URL, query strings, and fragments;
+- omit EC ID, internal `AuctionRequest.id`, IP, full URL, query strings, and fragments;
+- preserve the complete User-Agent for downstream data-sync classification;
 - generate a fresh random telemetry UUID unrelated to EC or request IDs;
 - emit provider-call rows for provider launch, parse, transport, timeout/no-response, no-bid, success, and abandoned outcomes where observable;
 - avoid invented seat-level no-bids;
@@ -573,12 +574,12 @@ Do this only if requested for a future implementation PR; auction telemetry alon
 - Launch, parse, transport, timeout, no-bid, success, abandoned statuses map correctly.
 - Mediated winners produce exactly one canonical winning bid row per slot.
 - Telemetry UUID is fresh and independent of `AuctionRequest.id`/EC.
-- Privacy fields are absent from serialized rows:
+- Sensitive identity fields are absent from serialized rows:
   - no EC ID;
   - no internal request ID;
   - no IP;
-  - no raw UA;
   - no full URL/query/fragment.
+- The complete User-Agent is preserved without edge-side classification.
 - Page path normalization is bounded and redacts dynamic segments.
 - NDJSON serialization emits valid single-line JSON rows and a trailing newline.
 

docs/superpowers/specs/2026-06-22-auction-prebid-metrics-tinybird-grafana-design.md

@@ -307,7 +307,8 @@ winner row. Never mark both an original and mediator copy as the same win.
 Emission is not gated by consent. `gdpr_applies` comes from
 `ConsentContext.gdpr_applies`; `consent_present` is `!ConsentContext::is_empty()`
 because an `EcContext` always contains a consent context, even when no signal was
-supplied.
+supplied. The complete request User-Agent is emitted for downstream data-sync
+classification, including on consent-denied observations.
 
 #### `auction_events_raw` row schema
 
@@ -325,6 +326,7 @@ All row kinds share these columns:
 | `region`           | Nullable(String)       | coarse geo                                        |
 | `is_mobile`        | UInt8                  | 0=desktop, 1=mobile, 2=unknown                    |
 | `is_known_browser` | UInt8                  | 0=bot, 1=browser, 2=unknown                       |
+| `user_agent`       | Nullable(String)       | complete request User-Agent for data syncs        |
 | `gdpr_applies`     | UInt8                  | 0/1                                               |
 | `consent_present`  | UInt8                  | 0/1                                               |
 
@@ -364,11 +366,13 @@ Bid fields:
 | `ad_domain`  | Nullable(String)                 | advertiser domain, optional                              |
 | `ad_id`      | Nullable(String)                 | creative ID, optional                                    |
 
-Privacy note: `auction_id` is generated independently for telemetry. No EC ID,
-internal auction request ID, full URL, IP, or raw user-agent string is emitted.
-Page paths use the same bounded route-normalization principle as access logs so
-a dynamic path segment cannot become a per-user identifier. Geo remains at
-country/region granularity.
+Data contract note: `auction_id` is generated independently for telemetry. No
+EC ID, internal auction request ID, full URL, or IP is emitted. The complete
+User-Agent is intentionally retained in the raw datasource so downstream data
+syncs, rather than edge code, own browser classification. Page paths use the
+same bounded route-normalization principle as access logs so a dynamic path
+segment cannot become a per-user identifier. Geo remains at country/region
+granularity.
 
 Device signals note: both `is_mobile` (0/1/2) and the bot-vs-browser bit come
 from the adapter's already-derived device signals. Phase 1 snapshots that struct
@@ -605,7 +609,8 @@ the direct-ingest architecture.
 - Provider launch, parse, transport, timeout, no-bid, and success outcomes are
   represented consistently on synchronous and split-phase paths.
 - Telemetry auction IDs are fresh random UUIDs unrelated to internal request IDs
-  and EC values. No EC ID, full URL, IP, or raw user-agent string is emitted.
+  and EC values. No EC ID, full URL, or IP is emitted. The complete User-Agent
+  is retained for downstream data-sync classification.
 - The Fastly adapter sends auction rows to Tinybird through a direct asynchronous
   backend POST using a Secret Store token scoped to APPEND on
   `auction_events_raw`; it does not configure or require Fastly real-time

tinybird/datasources/auction_events_raw.datasource

@@ -12,6 +12,7 @@ SCHEMA >
   `region` Nullable(String),
   `is_mobile` UInt8,
   `is_known_browser` UInt8,
+  `user_agent` Nullable(String),
   `gdpr_applies` UInt8,
   `consent_present` UInt8,
   `terminal_status` LowCardinality(Nullable(String)),