use original request sources for endpoint conditions

apps/aether-gateway/src/ai_serving/planner/passthrough/provider/family/request.rs

@@ -129,6 +129,7 @@ pub(crate) async fn resolve_local_same_format_provider_candidate_payload_parts(
             &prepared.mapped_model,
             spec,
             prepared.transport.endpoint.body_rules.as_ref(),
+            Some(&parts.headers),
             prepared.upstream_is_stream,
             prepared.kiro_auth.as_ref(),
             prepared.is_claude_code,

apps/aether-gateway/src/ai_serving/planner/passthrough/provider/request/body.rs

@@ -12,6 +12,7 @@ pub(crate) fn build_same_format_provider_request_body(
     mapped_model: &str,
     spec: LocalSameFormatProviderSpec,
     body_rules: Option<&Value>,
+    request_headers: Option<&http::HeaderMap>,
     upstream_is_stream: bool,
     kiro_auth: Option<&crate::ai_serving::transport::kiro::KiroRequestAuth>,
     is_claude_code: bool,
@@ -25,6 +26,7 @@ pub(crate) fn build_same_format_provider_request_body(
         source_model: body_json.get("model").and_then(Value::as_str),
         family: same_format_provider_family(spec.family),
         body_rules,
+        request_headers,
         upstream_is_stream,
         kiro_auth_config: kiro_auth.map(|auth| &auth.auth_config),
         is_claude_code,

apps/aether-gateway/src/ai_serving/planner/specialized/files/request.rs

@@ -103,6 +103,7 @@ pub(super) async fn resolve_local_gemini_files_candidate_payload_parts(
         body_is_empty,
         spec_metadata.decision_kind == GEMINI_FILES_UPLOAD_PLAN_KIND,
         transport.endpoint.body_rules.as_ref(),
+        Some(&parts.headers),
     ) {
         Ok(parts) => parts,
         Err(GeminiFilesRequestBodyError::BodyRulesUnsupportedForBinaryUpload) => {

apps/aether-gateway/src/ai_serving/planner/specialized/video/request.rs

@@ -124,6 +124,7 @@ pub(super) async fn resolve_local_video_create_candidate_payload_parts(
         provider_family,
         &mapped_model,
         transport.endpoint.body_rules.as_ref(),
+        Some(&parts.headers),
     ) else {
         mark_skipped_local_video_candidate_with_failure_diagnostic(
             state,

apps/aether-gateway/src/ai_serving/planner/standard/family/request.rs

@@ -176,7 +176,7 @@ pub(crate) async fn resolve_local_standard_candidate_payload_parts(
         )
         .await;
     let mut provider_request_body =
-        match crate::ai_serving::planner::standard::build_standard_request_body_with_model_directives(
+        match crate::ai_serving::planner::standard::build_standard_request_body_with_model_directives_and_request_headers(
             body_json,
             spec_metadata.api_format,
             &prepared_candidate.mapped_model,
@@ -190,6 +190,7 @@ pub(crate) async fn resolve_local_standard_candidate_payload_parts(
                 transport.endpoint.body_rules.as_ref()
             },
             Some(input.auth_context.api_key_id.as_str()),
+            Some(&parts.headers),
             enable_model_directives,
         ) {
             Some(body) => body,
@@ -353,6 +354,7 @@ async fn build_kiro_cross_format_payload_parts(
         &mapped_model,
         &kiro_auth.auth_config,
         transport.endpoint.body_rules.as_ref(),
+        Some(&parts.headers),
     ) {
         Some(body) => body,
         None => {

apps/aether-gateway/src/ai_serving/planner/standard/mod.rs

@@ -51,6 +51,7 @@ pub(crate) use crate::ai_serving::{
 };
 pub(crate) use crate::ai_serving::{
     build_standard_request_body, build_standard_request_body_with_model_directives,
+    build_standard_request_body_with_model_directives_and_request_headers,
     convert_openai_chat_request_to_claude_request, convert_openai_chat_request_to_gemini_request,
     convert_openai_chat_request_to_openai_responses_request, extract_openai_text_content,
     normalize_openai_responses_request_to_openai_chat_request, parse_openai_tool_result_content,

apps/aether-gateway/src/ai_serving/planner/standard/normalize/chat.rs

@@ -1,6 +1,6 @@
 use serde_json::Value;
 
-use crate::ai_serving::transport::apply_standard_provider_request_body_rules;
+use crate::ai_serving::transport::apply_standard_provider_request_body_rules_with_request_headers;
 use crate::ai_serving::{
     apply_codex_openai_responses_special_body_edits,
     apply_openai_responses_compact_special_body_edits,
@@ -14,6 +14,7 @@ pub(crate) fn build_local_openai_chat_request_body(
     mapped_model: &str,
     upstream_is_stream: bool,
     body_rules: Option<&Value>,
+    request_headers: &http::HeaderMap,
     enable_model_directives: bool,
 ) -> Option<Value> {
     let provider_request_body = surface_build_local_openai_chat_request_body(
@@ -22,7 +23,12 @@ pub(crate) fn build_local_openai_chat_request_body(
         upstream_is_stream,
         enable_model_directives,
     )?;
-    apply_standard_provider_request_body_rules(provider_request_body, body_rules, body_json)
+    apply_standard_provider_request_body_rules_with_request_headers(
+        provider_request_body,
+        body_rules,
+        body_json,
+        request_headers,
+    )
 }
 
 pub(crate) fn build_local_openai_chat_upstream_url(
@@ -40,6 +46,7 @@ pub(crate) fn build_cross_format_openai_chat_request_body(
     upstream_is_stream: bool,
     body_rules: Option<&Value>,
     user_api_key_id: Option<&str>,
+    request_headers: &http::HeaderMap,
     enable_model_directives: bool,
 ) -> Option<Value> {
     let provider_request_body = surface_build_cross_format_openai_chat_request_body(
@@ -50,7 +57,12 @@ pub(crate) fn build_cross_format_openai_chat_request_body(
         enable_model_directives,
     )?;
     let mut provider_request_body =
-        apply_standard_provider_request_body_rules(provider_request_body, body_rules, body_json)?;
+        apply_standard_provider_request_body_rules_with_request_headers(
+            provider_request_body,
+            body_rules,
+            body_json,
+            request_headers,
+        )?;
     apply_codex_openai_responses_special_body_edits(
         &mut provider_request_body,
         provider_type,

apps/aether-gateway/src/ai_serving/planner/standard/normalize/responses.rs

@@ -1,6 +1,6 @@
 use serde_json::Value;
 
-use crate::ai_serving::transport::apply_standard_provider_request_body_rules;
+use crate::ai_serving::transport::apply_standard_provider_request_body_rules_with_request_headers;
 use crate::ai_serving::{
     apply_codex_openai_responses_special_body_edits,
     apply_openai_responses_compact_special_body_edits,
@@ -17,6 +17,7 @@ pub(crate) fn build_local_openai_responses_request_body(
     provider_api_format: &str,
     body_rules: Option<&Value>,
     user_api_key_id: Option<&str>,
+    request_headers: &http::HeaderMap,
     enable_model_directives: bool,
 ) -> Option<Value> {
     let provider_request_body = surface_build_local_openai_responses_request_body(
@@ -26,7 +27,12 @@ pub(crate) fn build_local_openai_responses_request_body(
         enable_model_directives,
     )?;
     let mut provider_request_body =
-        apply_standard_provider_request_body_rules(provider_request_body, body_rules, body_json)?;
+        apply_standard_provider_request_body_rules_with_request_headers(
+            provider_request_body,
+            body_rules,
+            body_json,
+            request_headers,
+        )?;
     apply_codex_openai_responses_special_body_edits(
         &mut provider_request_body,
         provider_type,
@@ -50,6 +56,7 @@ pub(crate) fn build_cross_format_openai_responses_request_body(
     provider_type: &str,
     body_rules: Option<&Value>,
     user_api_key_id: Option<&str>,
+    request_headers: &http::HeaderMap,
     enable_model_directives: bool,
 ) -> Option<Value> {
     let provider_request_body = surface_build_cross_format_openai_responses_request_body(
@@ -61,7 +68,12 @@ pub(crate) fn build_cross_format_openai_responses_request_body(
         enable_model_directives,
     )?;
     let mut provider_request_body =
-        apply_standard_provider_request_body_rules(provider_request_body, body_rules, body_json)?;
+        apply_standard_provider_request_body_rules_with_request_headers(
+            provider_request_body,
+            body_rules,
+            body_json,
+            request_headers,
+        )?;
     apply_codex_openai_responses_special_body_edits(
         &mut provider_request_body,
         provider_type,

apps/aether-gateway/src/ai_serving/planner/standard/normalize/tests.rs

@@ -90,6 +90,7 @@ fn builds_openai_chat_cross_format_request_body_from_openai_responses_source() {
         "openai",
         None,
         None,
+        &http::HeaderMap::new(),
         false,
     )
     .expect("openai responses to openai chat body should build");
@@ -124,6 +125,7 @@ fn local_openai_responses_wrapper_preserves_body_order_after_edits() {
         "openai:responses",
         None,
         Some("key-123"),
+        &http::HeaderMap::new(),
         false,
     )
     .expect("local openai responses body should build");
@@ -162,6 +164,7 @@ fn local_openai_responses_compact_wrapper_strips_store_for_same_format_requests(
         "openai:responses:compact",
         None,
         None,
+        &http::HeaderMap::new(),
         false,
     )
     .expect("local openai compact body should build");
@@ -188,6 +191,7 @@ fn local_openai_responses_wrapper_applies_model_directive_before_body_rules() {
         "openai:responses",
         Some(&body_rules),
         None,
+        &http::HeaderMap::new(),
         true,
     )
     .expect("local openai responses body should build");
@@ -236,6 +240,7 @@ fn strips_metadata_for_codex_openai_responses_requests() {
         "codex",
         None,
         None,
+        &http::HeaderMap::new(),
         false,
     )
     .expect("claude cli to codex request should build");
@@ -269,6 +274,7 @@ fn applies_codex_defaults_unless_body_rules_handle_the_field() {
         "codex",
         Some(&body_rules),
         None,
+        &http::HeaderMap::new(),
         false,
     )
     .expect("claude cli to codex request should build");
@@ -297,6 +303,7 @@ fn injects_codex_prompt_cache_key_for_openai_responses_cross_format_requests() {
         "codex",
         None,
         Some("key-123"),
+        &http::HeaderMap::new(),
         false,
     )
     .expect("claude cli to codex request should build");
@@ -325,6 +332,7 @@ fn injects_codex_prompt_cache_key_for_openai_chat_cross_format_requests() {
         false,
         None,
         Some("key-123"),
+        &http::HeaderMap::new(),
         false,
     )
     .expect("openai chat to codex request should build");

apps/aether-gateway/src/ai_serving/planner/standard/openai/chat/decision/request.rs

@@ -129,6 +129,7 @@ pub(crate) async fn resolve_local_openai_chat_candidate_payload_parts(
             &prepared_candidate.mapped_model,
             upstream_is_stream,
             transport.endpoint.body_rules.as_ref(),
+            &parts.headers,
             enable_model_directives,
         ) else {
             mark_skipped_local_openai_chat_candidate_with_extra_data(
@@ -354,6 +355,7 @@ pub(crate) async fn resolve_local_openai_chat_candidate_payload_parts(
             transport.endpoint.body_rules.as_ref()
         },
         Some(input.auth_context.api_key_id.as_str()),
+        &parts.headers,
         enable_model_directives,
     ) else {
         mark_skipped_local_openai_chat_candidate_with_extra_data(
@@ -527,6 +529,7 @@ async fn build_kiro_openai_chat_cross_format_payload_parts(
         &mapped_model,
         &kiro_auth.auth_config,
         transport.endpoint.body_rules.as_ref(),
+        Some(&parts.headers),
     ) {
         Some(body) => body,
         None => {

apps/aether-gateway/src/ai_serving/planner/standard/openai/responses/decision/request.rs

@@ -244,6 +244,7 @@ pub(crate) async fn resolve_local_openai_responses_candidate_payload_parts(
                 transport.endpoint.body_rules.as_ref()
             },
             Some(input.auth_context.api_key_id.as_str()),
+            &parts.headers,
             enable_model_directives,
         )
     } else {
@@ -259,6 +260,7 @@ pub(crate) async fn resolve_local_openai_responses_candidate_payload_parts(
                 transport.endpoint.body_rules.as_ref()
             },
             Some(input.auth_context.api_key_id.as_str()),
+            &parts.headers,
             enable_model_directives,
         )
     }) else {
@@ -532,6 +534,7 @@ async fn build_kiro_openai_responses_payload_parts(
         &mapped_model,
         &kiro_auth.auth_config,
         transport.endpoint.body_rules.as_ref(),
+        Some(&parts.headers),
     ) {
         Some(body) => body,
         None => {

apps/aether-gateway/src/ai_serving/pure/mod.rs

@@ -20,11 +20,12 @@ pub(crate) use aether_ai_formats::api::{
     build_openai_image_provider_request_body, build_openai_responses_response,
     build_standard_request_body, build_standard_request_body_from_canonical,
     build_standard_request_body_from_canonical_with_model_directives,
-    build_standard_request_body_with_model_directives, calculate_kiro_context_input_tokens,
+    build_standard_request_body_with_model_directives,
-    canonicalize_tool_arguments, convert_claude_chat_response_to_openai_chat,
+    build_standard_request_body_with_model_directives_and_request_headers,
-    convert_claude_response_to_openai_responses, convert_gemini_chat_response_to_openai_chat,
+    calculate_kiro_context_input_tokens, canonicalize_tool_arguments,
-    convert_gemini_response_to_openai_responses, convert_openai_chat_request_to_claude_request,
+    convert_claude_chat_response_to_openai_chat, convert_claude_response_to_openai_responses,
-    convert_openai_chat_request_to_gemini_request,
+    convert_gemini_chat_response_to_openai_chat, convert_gemini_response_to_openai_responses,
+    convert_openai_chat_request_to_claude_request, convert_openai_chat_request_to_gemini_request,
     convert_openai_chat_request_to_openai_responses_request,
     convert_openai_chat_response_to_claude_chat, convert_openai_chat_response_to_gemini_chat,
     convert_openai_chat_response_to_openai_responses,

apps/aether-gateway/src/ai_serving/transport.rs

@@ -47,11 +47,13 @@ pub(crate) mod vertex {
 }
 
 pub(crate) use aether_provider_transport::{
-    append_transport_diagnostics_to_value, apply_local_body_rules, apply_local_header_rules,
+    append_transport_diagnostics_to_value, apply_local_body_rules,
-    apply_standard_provider_request_body_rules, body_rules_are_locally_supported,
+    apply_local_body_rules_with_request_headers, apply_local_header_rules,
-    body_rules_handle_path, build_cross_format_openai_chat_upstream_url,
+    apply_local_header_rules_with_request_headers, apply_standard_provider_request_body_rules,
-    build_cross_format_openai_responses_upstream_url, build_gemini_files_headers,
+    apply_standard_provider_request_body_rules_with_request_headers,
-    build_gemini_files_request_body, build_gemini_files_upstream_url,
+    body_rules_are_locally_supported, body_rules_handle_path,
+    build_cross_format_openai_chat_upstream_url, build_cross_format_openai_responses_upstream_url,
+    build_gemini_files_headers, build_gemini_files_request_body, build_gemini_files_upstream_url,
     build_kiro_cross_format_upstream_url, build_local_openai_chat_upstream_url,
     build_local_openai_responses_upstream_url, build_openai_image_headers,
     build_openai_image_upstream_url, build_passthrough_headers, build_request_trace_proxy_value,

apps/aether-gateway/src/handlers/admin/provider/query/models.rs

@@ -245,11 +245,35 @@ fn provider_query_extract_request_headers(payload: &Value) -> HeaderMap {
 }
 
 fn provider_query_build_test_request_body(payload: &Value, model: &str) -> Value {
+    provider_query_build_test_request_body_with_model_policy(payload, model, false)
+}
+
+fn provider_query_build_test_request_body_for_route(
+    payload: &Value,
+    model: &str,
+    route_path: &str,
+) -> Value {
+    provider_query_build_test_request_body_with_model_policy(
+        payload,
+        model,
+        route_path.ends_with("/test-model-failover"),
+    )
+}
+
+fn provider_query_build_test_request_body_with_model_policy(
+    payload: &Value,
+    model: &str,
+    override_custom_model: bool,
+) -> Value {
     if let Some(mut body) = provider_query_extract_request_body(payload) {
         if let Some(object) = body.as_object_mut() {
-            object
+            if override_custom_model {
-                .entry("model".to_string())
+                object.insert("model".to_string(), Value::String(model.to_string()));
-                .or_insert_with(|| Value::String(model.to_string()));
+            } else {
+                object
+                    .entry("model".to_string())
+                    .or_insert_with(|| Value::String(model.to_string()));
+            }
         }
         return body;
     }
@@ -791,7 +815,12 @@ async fn provider_query_execute_kiro_test_candidate(
         });
     };
 
-    let request_body = provider_query_build_test_request_body(payload, &candidate.effective_model);
+    let request_body = provider_query_build_test_request_body_for_route(
+        payload,
+        &candidate.effective_model,
+        route_path,
+    );
+    let incoming_request_headers = provider_query_extract_request_headers(payload);
     let request_model =
         provider_query_request_body_model(&request_body, &candidate.effective_model);
     let provider_request_body = match build_kiro_provider_request_body(
@@ -799,6 +828,7 @@ async fn provider_query_execute_kiro_test_candidate(
         request_model,
         &kiro_auth.auth_config,
         transport.endpoint.body_rules.as_ref(),
+        Some(&incoming_request_headers),
     ) {
         Some(body) => body,
         None => {
@@ -821,7 +851,7 @@ async fn provider_query_execute_kiro_test_candidate(
         .uri(route_path)
         .body(())
         .map_err(|err| GatewayError::Internal(err.to_string()))?;
-    *synthetic_request.headers_mut() = provider_query_extract_request_headers(payload);
+    *synthetic_request.headers_mut() = incoming_request_headers;
     let (parts, _) = synthetic_request.into_parts();
 
     let request_url = build_kiro_generate_assistant_response_url(
@@ -949,8 +979,12 @@ async fn provider_query_execute_standard_test_candidate(
         });
     }
 
-    let original_request_body =
+    let original_request_body = provider_query_build_test_request_body_for_route(
-        provider_query_build_test_request_body(payload, &candidate.effective_model);
+        payload,
+        &candidate.effective_model,
+        route_path,
+    );
+    let incoming_request_headers = provider_query_extract_request_headers(payload);
     let mut request_body = original_request_body.clone();
     if let Some(object) = request_body.as_object_mut() {
         object.insert("stream".to_string(), Value::Bool(false));
@@ -975,10 +1009,11 @@ async fn provider_query_execute_standard_test_candidate(
                     format!("Provider request body could not be built for {provider_api_format}"),
                 ));
             };
-            if !crate::provider_transport::apply_local_body_rules(
+            if !crate::provider_transport::apply_local_body_rules_with_request_headers(
                 &mut provider_request_body,
                 transport.endpoint.body_rules.as_ref(),
                 Some(&request_body),
+                Some(&incoming_request_headers),
             ) {
                 return Ok(provider_query_skipped_execution_outcome(
                     request_body.clone(),
@@ -1001,10 +1036,11 @@ async fn provider_query_execute_standard_test_candidate(
                     format!("Provider request body could not be built for {provider_api_format}"),
                 ));
             };
-            if !crate::provider_transport::apply_local_body_rules(
+            if !crate::provider_transport::apply_local_body_rules_with_request_headers(
                 &mut provider_request_body,
                 transport.endpoint.body_rules.as_ref(),
                 Some(&request_body),
+                Some(&incoming_request_headers),
             ) {
                 return Ok(provider_query_skipped_execution_outcome(
                     request_body.clone(),
@@ -1027,10 +1063,11 @@ async fn provider_query_execute_standard_test_candidate(
                     format!("Provider request body could not be built for {provider_api_format}"),
                 ));
             };
-            if !crate::provider_transport::apply_local_body_rules(
+            if !crate::provider_transport::apply_local_body_rules_with_request_headers(
                 &mut provider_request_body,
                 transport.endpoint.body_rules.as_ref(),
                 Some(&request_body),
+                Some(&incoming_request_headers),
             ) {
                 return Ok(provider_query_skipped_execution_outcome(
                     request_body.clone(),
@@ -1104,7 +1141,7 @@ async fn provider_query_execute_standard_test_candidate(
         .uri(route_path)
         .body(())
         .map_err(|err| GatewayError::Internal(err.to_string()))?;
-    *synthetic_request.headers_mut() = provider_query_extract_request_headers(payload);
+    *synthetic_request.headers_mut() = incoming_request_headers;
     let (parts, _) = synthetic_request.into_parts();
 
     let request_url = crate::provider_transport::build_transport_request_url(
@@ -1166,12 +1203,13 @@ async fn provider_query_execute_standard_test_candidate(
     } else {
         vec![auth_header.as_deref().unwrap_or_default(), "content-type"]
     };
-    if !state.apply_local_header_rules(
+    if !crate::provider_transport::apply_local_header_rules_with_request_headers(
         &mut request_headers,
         transport.endpoint.header_rules.as_ref(),
         &protected_headers,
         &provider_request_body,
         Some(&request_body),
+        Some(&parts.headers),
     ) {
         return Ok(ProviderQueryExecutionOutcome {
             status: "failed",
@@ -1983,6 +2021,24 @@ mod tests {
         assert_eq!(body["model"], json!("fallback-model"));
     }
 
+    #[test]
+    fn provider_query_failover_request_body_overrides_custom_model() {
+        let payload = json!({
+            "request_body": {
+                "model": "custom-upstream-model",
+                "messages": []
+            }
+        });
+
+        let body = provider_query_build_test_request_body_for_route(
+            &payload,
+            "failover-model",
+            "/api/admin/provider-query/test-model-failover",
+        );
+
+        assert_eq!(body["model"], json!("failover-model"));
+    }
+
     #[test]
     fn provider_query_request_body_model_uses_non_empty_string_only() {
         let custom = json!({ "model": " custom-model " });

apps/aether-gateway/src/tests/architecture/ai_serving.rs

@@ -2632,7 +2632,7 @@ fn ai_serving_standard_attempts_consume_eligible_local_candidates_without_transp
         "build_complete_passthrough_headers_with_auth(",
         "build_claude_passthrough_headers(",
         "build_openai_passthrough_headers(",
-        "apply_local_header_rules(",
+        "apply_local_header_rules_with_request_headers(",
         "uses_vertex_api_key_query_auth(",
     ] {
         assert!(

crates/aether-ai-formats/src/api.rs

@@ -119,6 +119,7 @@ pub use crate::request::standard::{
     build_local_openai_responses_request_body,
     build_local_openai_responses_request_body_with_model_directives, build_standard_request_body,
     build_standard_request_body_with_model_directives,
+    build_standard_request_body_with_model_directives_and_request_headers,
     claude::{
         resolve_stream_spec as resolve_claude_stream_spec,
         resolve_sync_spec as resolve_claude_sync_spec,

crates/aether-ai-formats/src/provider_compat/proxy/rules.rs

@@ -9,11 +9,17 @@ use serde_json::{Map, Value};
 const ORIGINAL_PLACEHOLDER: &str = "{{$original}}";
 const ITEM_PREFIX: &str = "$item.";
 const ITEM_EXACT: &str = "$item";
-const CONDITION_SOURCES: &[&str] = &["current", "original"];
+const CONDITION_SOURCES: &[&str] = &["body", "request_headers", "headers", "original", "current"];
 const CONDITION_TYPE_VALUES: &[&str] = &["string", "number", "boolean", "array", "object", "null"];
 
 static RANGE_RE: OnceLock<Regex> = OnceLock::new();
 
+#[derive(Clone, Copy)]
+enum ConditionHeaders<'a> {
+    Request(&'a http::HeaderMap),
+    Map(&'a BTreeMap<String, String>),
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 enum BodyPathSegment {
     Key(String),
@@ -34,6 +40,35 @@ pub fn apply_local_header_rules(
     protected_keys: &[&str],
     body: &Value,
     original_body: Option<&Value>,
+) -> bool {
+    apply_local_header_rules_inner(headers, rules, protected_keys, body, original_body, None)
+}
+
+pub fn apply_local_header_rules_with_request_headers(
+    headers: &mut BTreeMap<String, String>,
+    rules: Option<&Value>,
+    protected_keys: &[&str],
+    body: &Value,
+    original_body: Option<&Value>,
+    request_headers: Option<&http::HeaderMap>,
+) -> bool {
+    apply_local_header_rules_inner(
+        headers,
+        rules,
+        protected_keys,
+        body,
+        original_body,
+        request_headers.map(ConditionHeaders::Request),
+    )
+}
+
+fn apply_local_header_rules_inner(
+    headers: &mut BTreeMap<String, String>,
+    rules: Option<&Value>,
+    protected_keys: &[&str],
+    body: &Value,
+    original_body: Option<&Value>,
+    request_headers: Option<ConditionHeaders<'_>>,
 ) -> bool {
     let Some(rules) = rules else {
         return true;
@@ -54,7 +89,8 @@ pub fn apply_local_header_rules(
             if !condition_is_locally_supported(condition) {
                 continue;
             }
-            if !evaluate_local_condition(body, condition, original_body) {
+            let condition_headers = request_headers.or(Some(ConditionHeaders::Map(&*headers)));
+            if !evaluate_local_condition(body, condition, original_body, condition_headers) {
                 continue;
             }
         }
@@ -178,6 +214,29 @@ pub fn apply_local_body_rules(
     body: &mut Value,
     rules: Option<&Value>,
     original_body: Option<&Value>,
+) -> bool {
+    apply_local_body_rules_inner(body, rules, original_body, None)
+}
+
+pub fn apply_local_body_rules_with_request_headers(
+    body: &mut Value,
+    rules: Option<&Value>,
+    original_body: Option<&Value>,
+    request_headers: Option<&http::HeaderMap>,
+) -> bool {
+    apply_local_body_rules_inner(
+        body,
+        rules,
+        original_body,
+        request_headers.map(ConditionHeaders::Request),
+    )
+}
+
+fn apply_local_body_rules_inner(
+    body: &mut Value,
+    rules: Option<&Value>,
+    original_body: Option<&Value>,
+    request_headers: Option<ConditionHeaders<'_>>,
 ) -> bool {
     let Some(rules) = rules else {
         return true;
@@ -197,7 +256,9 @@ pub fn apply_local_body_rules(
             if !condition_is_locally_supported(condition) {
                 continue;
             }
-            if !item_condition && !evaluate_local_condition(body, condition, original_body) {
+            if !item_condition
+                && !evaluate_local_condition(body, condition, original_body, request_headers)
+            {
                 continue;
             }
         }
@@ -220,11 +281,14 @@ pub fn apply_local_body_rules(
                 let targets = iter_wildcard_targets(
                     body,
                     &path,
-                    condition,
+                    WildcardTargetOptions {
-                    item_condition,
+                        condition,
-                    original_body,
+                        item_condition,
-                    false,
+                        original_body,
-                    false,
+                        request_headers,
+                        require_leaf: false,
+                        reverse: false,
+                    },
                 );
                 let value_template = rule.get("value").cloned().unwrap_or(Value::Null);
                 for target_path in targets {
@@ -248,11 +312,14 @@ pub fn apply_local_body_rules(
                 for target_path in iter_wildcard_targets(
                     body,
                     &path,
-                    condition,
+                    WildcardTargetOptions {
-                    item_condition,
+                        condition,
-                    original_body,
+                        item_condition,
-                    true,
+                        original_body,
-                    true,
+                        request_headers,
+                        require_leaf: true,
+                        reverse: true,
+                    },
                 ) {
                     let _ = delete_nested_value(body, &target_path);
                 }
@@ -289,11 +356,14 @@ pub fn apply_local_body_rules(
                 for target_path in iter_wildcard_targets(
                     body,
                     &path,
-                    condition,
+                    WildcardTargetOptions {
-                    item_condition,
+                        condition,
-                    original_body,
+                        item_condition,
-                    true,
+                        original_body,
-                    false,
+                        request_headers,
+                        require_leaf: true,
+                        reverse: false,
+                    },
                 ) {
                     if let Some(target) = get_nested_value_mut(body, &target_path) {
                         if let Some(values) = target.as_array_mut() {
@@ -352,11 +422,14 @@ pub fn apply_local_body_rules(
                 for target_path in iter_wildcard_targets(
                     body,
                     &path,
-                    condition,
+                    WildcardTargetOptions {
-                    item_condition,
+                        condition,
-                    original_body,
+                        item_condition,
-                    true,
+                        original_body,
-                    false,
+                        request_headers,
+                        require_leaf: true,
+                        reverse: false,
+                    },
                 ) {
                     if let Some(target) = get_nested_value_mut(body, &target_path) {
                         let Some(current) = target.as_str().map(str::to_owned) else {
@@ -394,7 +467,7 @@ fn condition_is_locally_supported(condition: &Value) -> bool {
         .get("source")
         .and_then(Value::as_str)
         .map(str::trim)
-        .unwrap_or("current");
+        .unwrap_or("body");
     if !CONDITION_SOURCES.contains(&source) {
         return false;
     }
@@ -402,15 +475,13 @@ fn condition_is_locally_supported(condition: &Value) -> bool {
     let Some(op) = condition.get("op").and_then(Value::as_str).map(str::trim) else {
         return false;
     };
-    let Some(path) = condition
+    let Some(path) = condition.get("path").and_then(Value::as_str) else {
-        .get("path")
-        .and_then(Value::as_str)
-        .map(str::trim)
-        .and_then(parse_body_path)
-    else {
         return false;
     };
-    if path.is_empty() {
+    if path.trim().is_empty() {
+        return false;
+    }
+    if !condition_source_is_headers(source) && parse_body_path(path).is_none() {
         return false;
     }
 
@@ -443,6 +514,7 @@ fn evaluate_local_condition(
     body: &Value,
     condition: &Value,
     original_body: Option<&Value>,
+    request_headers: Option<ConditionHeaders<'_>>,
 ) -> bool {
     let Some(condition) = condition.as_object() else {
         return false;
@@ -450,41 +522,40 @@ fn evaluate_local_condition(
 
     if let Some(children) = condition.get("all").and_then(Value::as_array) {
         return !children.is_empty()
-            && children
+            && children.iter().all(|child| {
-                .iter()
+                evaluate_local_condition(body, child, original_body, request_headers)
-                .all(|child| evaluate_local_condition(body, child, original_body));
+            });
     }
     if let Some(children) = condition.get("any").and_then(Value::as_array) {
         return !children.is_empty()
-            && children
+            && children.iter().any(|child| {
-                .iter()
+                evaluate_local_condition(body, child, original_body, request_headers)
-                .any(|child| evaluate_local_condition(body, child, original_body));
+            });
     }
 
     let source = condition
         .get("source")
         .and_then(Value::as_str)
         .map(str::trim)
-        .unwrap_or("current");
+        .unwrap_or("body");
-    let target = if source.eq_ignore_ascii_case("original") {
-        original_body.unwrap_or(body)
-    } else {
-        body
-    };
 
     let Some(op) = condition.get("op").and_then(Value::as_str).map(str::trim) else {
         return false;
     };
-    let Some(path) = condition
+    let Some(path) = condition.get("path").and_then(Value::as_str).map(str::trim) else {
-        .get("path")
-        .and_then(Value::as_str)
-        .map(str::trim)
-        .and_then(parse_body_path)
-    else {
         return false;
     };
 
-    let current_value = get_nested_value(target, &path);
+    let current_value = if condition_source_is_headers(source) {
+        request_headers.and_then(|headers| get_header_condition_value(headers, path))
+    } else {
+        let target = if source.eq_ignore_ascii_case("current") {
+            body
+        } else {
+            original_body.unwrap_or(body)
+        };
+        parse_body_path(path).and_then(|path| get_nested_value(target, &path))
+    };
     if op == "exists" {
         return current_value.is_some();
     }
@@ -556,6 +627,24 @@ fn evaluate_local_condition(
     }
 }
 
+fn condition_source_is_headers(source: &str) -> bool {
+    source.eq_ignore_ascii_case("request_headers") || source.eq_ignore_ascii_case("headers")
+}
+
+fn get_header_condition_value(headers: ConditionHeaders<'_>, path: &str) -> Option<Value> {
+    let key = path.trim().to_ascii_lowercase();
+    if key.is_empty() {
+        return None;
+    }
+    match headers {
+        ConditionHeaders::Request(headers) => headers
+            .get(key.as_str())
+            .and_then(|value| value.to_str().ok())
+            .map(|value| Value::String(value.trim().to_string())),
+        ConditionHeaders::Map(headers) => headers.get(&key).cloned().map(Value::String),
+    }
+}
+
 fn json_number(value: &Value) -> Option<f64> {
     value.as_f64().filter(|_| !value.is_boolean())
 }
@@ -887,29 +976,34 @@ fn expand_wildcard_paths_recursive(
     }
 }
 
+struct WildcardTargetOptions<'a> {
+    condition: Option<&'a Value>,
+    item_condition: bool,
+    original_body: Option<&'a Value>,
+    request_headers: Option<ConditionHeaders<'a>>,
+    require_leaf: bool,
+    reverse: bool,
+}
+
 fn iter_wildcard_targets(
     body: &Value,
     path: &[BodyPathSegment],
-    condition: Option<&Value>,
+    options: WildcardTargetOptions<'_>,
-    item_condition: bool,
-    original_body: Option<&Value>,
-    require_leaf: bool,
-    reverse: bool,
 ) -> Vec<Vec<BodyPathSegment>> {
     if !has_wildcard(path) {
         return vec![path.to_vec()];
     }
 
-    let mut expanded = expand_wildcard_paths(body, path, require_leaf);
+    let mut expanded = expand_wildcard_paths(body, path, options.require_leaf);
-    if reverse {
+    if options.reverse {
         expanded.reverse();
     }
 
-    if !item_condition {
+    if !options.item_condition {
         return expanded;
     }
 
-    let Some(condition) = condition else {
+    let Some(condition) = options.condition else {
         return expanded;
     };
 
@@ -918,7 +1012,12 @@ fn iter_wildcard_targets(
         .filter(|concrete_path| {
             let prefix = get_item_prefix_from_concrete(concrete_path, path);
             let resolved = resolve_item_condition(condition, &prefix);
-            evaluate_local_condition(body, &resolved, original_body)
+            evaluate_local_condition(
+                body,
+                &resolved,
+                options.original_body,
+                options.request_headers,
+            )
         })
         .collect()
 }
@@ -1194,8 +1293,10 @@ fn rename_nested_value(
 #[cfg(test)]
 mod tests {
     use super::{
-        apply_local_body_rules, apply_local_header_rules, body_rules_are_locally_supported,
+        apply_local_body_rules, apply_local_body_rules_with_request_headers,
-        body_rules_handle_path, header_rules_are_locally_supported,
+        apply_local_header_rules, apply_local_header_rules_with_request_headers,
+        body_rules_are_locally_supported, body_rules_handle_path,
+        header_rules_are_locally_supported,
     };
 
     #[test]
@@ -1242,7 +1343,7 @@ mod tests {
             Some(&rules),
             &[],
             &serde_json::json!({"metadata":{"mode":"safe"}}),
-            Some(&serde_json::json!({"metadata":{"client":"desktop"}})),
+            Some(&serde_json::json!({"metadata":{"mode":"safe","client":"desktop"}})),
         ));
         assert_eq!(headers.get("x-added").map(String::as_str), Some("1"));
         assert_eq!(
@@ -1251,6 +1352,32 @@ mod tests {
         );
     }
 
+    #[test]
+    fn header_rules_can_read_original_request_header_conditions() {
+        let rules = serde_json::json!([
+            {"action":"set","key":"x-applied","value":"yes","condition":{"source":"request_headers","path":"X-Mode","op":"eq","value":"debug"}},
+            {"action":"set","key":"x-skipped","value":"yes","condition":{"source":"request_headers","path":"x-missing","op":"exists"}}
+        ]);
+        let mut request_headers = http::HeaderMap::new();
+        request_headers.insert("x-mode", "debug".parse().unwrap());
+
+        let mut headers = std::collections::BTreeMap::from([(
+            "x-mode".to_string(),
+            "provider-value".to_string(),
+        )]);
+        assert!(apply_local_header_rules_with_request_headers(
+            &mut headers,
+            Some(&rules),
+            &[],
+            &serde_json::json!({}),
+            None,
+            Some(&request_headers),
+        ));
+
+        assert_eq!(headers.get("x-applied").map(String::as_str), Some("yes"));
+        assert!(!headers.contains_key("x-skipped"));
+    }
+
     #[test]
     fn body_rules_support_all_runtime_actions() {
         let rules = serde_json::json!([
@@ -1333,6 +1460,15 @@ mod tests {
         assert!(body_rules_are_locally_supported(Some(&rules)));
 
         let original = serde_json::json!({
+            "num": 10,
+            "text": "alpha-beta",
+            "tags": ["red", "green"],
+            "choice": "b",
+            "flag": true,
+            "maybe_null": null,
+            "profile": {
+                "name": "Ada"
+            },
             "legacy": {
                 "present": 1
             }
@@ -1378,6 +1514,53 @@ mod tests {
         assert_eq!(body["results"], expected);
     }
 
+    #[test]
+    fn body_conditions_default_to_original_request_body() {
+        let rules = serde_json::json!([
+            {"action":"set","path":"model","value":"provider-model"},
+            {"action":"set","path":"metadata.original_hit","value":true,"condition":{"path":"model","op":"eq","value":"client-model"}},
+            {"action":"set","path":"metadata.current_hit","value":true,"condition":{"path":"model","op":"eq","value":"provider-model"}}
+        ]);
+        let original = serde_json::json!({
+            "model": "client-model"
+        });
+        let mut body = original.clone();
+
+        assert!(apply_local_body_rules(
+            &mut body,
+            Some(&rules),
+            Some(&original)
+        ));
+
+        assert_eq!(body["model"], "provider-model");
+        assert_eq!(body["metadata"]["original_hit"], true);
+        assert!(body["metadata"].get("current_hit").is_none());
+    }
+
+    #[test]
+    fn body_rules_can_read_original_request_header_conditions() {
+        let rules = serde_json::json!([
+            {"action":"set","path":"metadata.from_header","value":true,"condition":{"source":"request_headers","path":"X-Mode","op":"eq","value":"debug"}},
+            {"action":"set","path":"metadata.contains","value":true,"condition":{"source":"headers","path":"x-feature","op":"contains","value":"beta"}},
+            {"action":"set","path":"metadata.skipped","value":true,"condition":{"source":"request_headers","path":"x-mode","op":"eq","value":"prod"}}
+        ]);
+        let mut request_headers = http::HeaderMap::new();
+        request_headers.insert("x-mode", "debug".parse().unwrap());
+        request_headers.insert("x-feature", "alpha,beta".parse().unwrap());
+        let mut body = serde_json::json!({});
+
+        assert!(apply_local_body_rules_with_request_headers(
+            &mut body,
+            Some(&rules),
+            None,
+            Some(&request_headers),
+        ));
+
+        assert_eq!(body["metadata"]["from_header"], true);
+        assert_eq!(body["metadata"]["contains"], true);
+        assert!(body["metadata"].get("skipped").is_none());
+    }
+
     #[test]
     fn body_rules_tolerate_invalid_regex_flags_and_negative_count() {
         let invalid_flags = serde_json::json!([

crates/aether-ai-formats/src/request/standard/matrix.rs

@@ -8,7 +8,7 @@ use aether_ai_formats::protocol::conversion::request::{
     normalize_openai_responses_request_to_openai_chat_request,
 };
 use aether_ai_formats::protocol::registry::{convert_request, FormatContext};
-use aether_ai_formats::provider_compat::proxy::rules::apply_local_body_rules;
+use aether_ai_formats::provider_compat::proxy::rules::apply_local_body_rules_with_request_headers;
 use serde_json::Value;
 
 use crate::request::model_directives::apply_model_directive_overrides_from_request;
@@ -57,6 +57,35 @@ pub fn build_standard_request_body_with_model_directives(
     body_rules: Option<&Value>,
     user_api_key_id: Option<&str>,
     enable_model_directives: bool,
+) -> Option<Value> {
+    build_standard_request_body_with_model_directives_and_request_headers(
+        body_json,
+        client_api_format,
+        mapped_model,
+        provider_type,
+        provider_api_format,
+        request_path,
+        upstream_is_stream,
+        body_rules,
+        user_api_key_id,
+        None,
+        enable_model_directives,
+    )
+}
+
+#[allow(clippy::too_many_arguments)]
+pub fn build_standard_request_body_with_model_directives_and_request_headers(
+    body_json: &Value,
+    client_api_format: &str,
+    mapped_model: &str,
+    provider_type: &str,
+    provider_api_format: &str,
+    request_path: &str,
+    upstream_is_stream: bool,
+    body_rules: Option<&Value>,
+    user_api_key_id: Option<&str>,
+    request_headers: Option<&http::HeaderMap>,
+    enable_model_directives: bool,
 ) -> Option<Value> {
     let format_context = FormatContext::default()
         .with_mapped_model(mapped_model)
@@ -80,7 +109,12 @@ pub fn build_standard_request_body_with_model_directives(
         );
     }
 
-    if !apply_local_body_rules(&mut provider_request_body, body_rules, Some(body_json)) {
+    if !apply_local_body_rules_with_request_headers(
+        &mut provider_request_body,
+        body_rules,
+        Some(body_json),
+        request_headers,
+    ) {
         return None;
     }
     apply_codex_openai_responses_special_body_edits(

crates/aether-ai-formats/src/request/standard/mod.rs

@@ -16,6 +16,7 @@ pub use family::{LocalStandardSourceFamily, LocalStandardSourceMode, LocalStanda
 pub use matrix::{
     build_standard_request_body, build_standard_request_body_from_canonical_with_model_directives,
     build_standard_request_body_with_model_directives,
+    build_standard_request_body_with_model_directives_and_request_headers,
     normalize_standard_request_to_openai_chat_request,
 };
 pub use normalize::{

crates/aether-provider-transport/src/gemini_files.rs

@@ -4,7 +4,9 @@ use serde_json::{json, Value};
 
 use crate::auth::{build_passthrough_headers_with_auth, resolve_local_gemini_auth};
 use crate::policy::local_gemini_transport_unsupported_reason_with_network;
-use crate::rules::{apply_local_body_rules, apply_local_header_rules};
+use crate::rules::{
+    apply_local_body_rules_with_request_headers, apply_local_header_rules_with_request_headers,
+};
 use crate::snapshot::GatewayProviderTransportSnapshot;
 use crate::url::build_gemini_files_passthrough_url;
 
@@ -70,6 +72,7 @@ pub fn build_gemini_files_request_body(
     body_is_empty: bool,
     is_upload: bool,
     body_rules: Option<&Value>,
+    request_headers: Option<&http::HeaderMap>,
 ) -> Result<GeminiFilesRequestBodyParts, GeminiFilesRequestBodyError> {
     let mut provider_request_body = if is_upload && !body_is_empty && body_base64.is_none() {
         Some(body_json.clone())
@@ -88,7 +91,12 @@ pub fn build_gemini_files_request_body(
         return Err(GeminiFilesRequestBodyError::BodyRulesUnsupportedForBinaryUpload);
     }
     if let Some(body) = provider_request_body.as_mut() {
-        if !apply_local_body_rules(body, body_rules, Some(body_json)) {
+        if !apply_local_body_rules_with_request_headers(
+            body,
+            body_rules,
+            Some(body_json),
+            request_headers,
+        ) {
             return Err(GeminiFilesRequestBodyError::BodyRulesApplyFailed);
         }
     }
@@ -116,12 +124,13 @@ pub fn build_gemini_files_headers(
         .as_ref()
         .or_else(|| (!input.original_body_is_empty).then_some(input.original_request_body_json))
         .unwrap_or(&null_original_request_body);
-    if !apply_local_header_rules(
+    if !apply_local_header_rules_with_request_headers(
         &mut provider_request_headers,
         input.header_rules,
         &[input.auth_header, "content-type"],
         input.provider_request_body.unwrap_or(original_request_body),
         Some(original_request_body),
+        Some(input.headers),
     ) {
         return None;
     }
@@ -216,6 +225,7 @@ mod tests {
             Some(&json!([
                 {"action":"set","path":"metadata.source","value":"local"}
             ])),
+            None,
         )
         .expect("body should build");
 
@@ -236,7 +246,8 @@ mod tests {
                 Some("YWJj"),
                 false,
                 true,
-                Some(&json!([{"action":"set","path":"x","value":1}]))
+                Some(&json!([{"action":"set","path":"x","value":1}])),
+                None,
             ),
             Err(GeminiFilesRequestBodyError::BodyRulesUnsupportedForBinaryUpload)
         );

crates/aether-provider-transport/src/kiro.rs

@@ -25,10 +25,10 @@ pub use policy::{
 };
 pub use refresh::KiroOAuthRefreshAdapter;
 pub use request::{
-    apply_local_body_rules, apply_local_header_rules, body_rules_are_locally_supported,
+    apply_local_body_rules_with_request_headers, apply_local_header_rules_with_request_headers,
-    build_kiro_provider_headers, build_kiro_provider_request_body,
+    body_rules_are_locally_supported, build_kiro_provider_headers,
-    header_rules_are_locally_supported, supports_local_kiro_request_shape,
+    build_kiro_provider_request_body, header_rules_are_locally_supported,
-    KiroProviderHeadersInput,
+    supports_local_kiro_request_shape, KiroProviderHeadersInput,
 };
 pub use url::{
     build_kiro_generate_assistant_response_url, build_kiro_mcp_url,

crates/aether-provider-transport/src/kiro/request.rs

@@ -3,8 +3,8 @@ use std::collections::BTreeMap;
 use serde_json::{json, Value};
 
 pub use super::super::rules::{
-    apply_local_body_rules, apply_local_header_rules, body_rules_are_locally_supported,
+    apply_local_body_rules_with_request_headers, apply_local_header_rules_with_request_headers,
-    header_rules_are_locally_supported,
+    body_rules_are_locally_supported, header_rules_are_locally_supported,
 };
 use super::super::should_skip_upstream_passthrough_header;
 use super::converter::convert_claude_messages_to_conversation_state;
@@ -23,6 +23,7 @@ pub fn build_kiro_provider_request_body(
     mapped_model: &str,
     auth_config: &KiroAuthConfig,
     body_rules: Option<&Value>,
+    request_headers: Option<&http::HeaderMap>,
 ) -> Option<Value> {
     let conversation_state =
         convert_claude_messages_to_conversation_state(body_json, mapped_model)?;
@@ -70,7 +71,12 @@ pub fn build_kiro_provider_request_body(
         );
     }
 
-    if !apply_local_body_rules(&mut provider_request_body, body_rules, Some(body_json)) {
+    if !apply_local_body_rules_with_request_headers(
+        &mut provider_request_body,
+        body_rules,
+        Some(body_json),
+        request_headers,
+    ) {
         return None;
     }
 
@@ -119,12 +125,13 @@ pub fn build_kiro_provider_headers(
         out.insert(key, value.to_string());
     }
 
-    if !apply_local_header_rules(
+    if !apply_local_header_rules_with_request_headers(
         &mut out,
         header_rules,
         &[auth_header, "content-type"],
         provider_request_body,
         Some(original_request_body),
+        Some(headers),
     ) {
         return None;
     }
@@ -202,6 +209,7 @@ mod tests {
             Some(&json!([
                 {"action":"set","path":"debugTag","value":"kiro-local"}
             ])),
+            None,
         )
         .expect("payload should build");
 
@@ -292,6 +300,7 @@ mod tests {
             "claude-sonnet-4-upstream",
             &auth_config,
             None,
+            None,
         )
         .expect("payload should build");
 

crates/aether-provider-transport/src/lib.rs

@@ -75,7 +75,8 @@ pub use request_url::{
     TransportRequestUrlParams,
 };
 pub use rules::{
-    apply_local_body_rules, apply_local_header_rules, body_rules_are_locally_supported,
+    apply_local_body_rules, apply_local_body_rules_with_request_headers, apply_local_header_rules,
+    apply_local_header_rules_with_request_headers, body_rules_are_locally_supported,
     body_rules_handle_path, header_rules_are_locally_supported,
 };
 pub use same_format_provider::{
@@ -94,8 +95,9 @@ pub use snapshot::{
     ProviderTransportSnapshotSource,
 };
 pub use standard::{
-    apply_standard_provider_request_body_rules, build_standard_plan_fallback_headers,
+    apply_standard_provider_request_body_rules,
-    build_standard_plan_fallback_openai_chat_url,
+    apply_standard_provider_request_body_rules_with_request_headers,
+    build_standard_plan_fallback_headers, build_standard_plan_fallback_openai_chat_url,
     build_standard_plan_fallback_openai_responses_url, build_standard_provider_request_headers,
     StandardPlanFallbackAcceptPolicy, StandardPlanFallbackHeadersInput,
     StandardProviderRequestHeaders, StandardProviderRequestHeadersInput,

crates/aether-provider-transport/src/openai_image.rs

@@ -4,7 +4,7 @@ use serde_json::Value;
 
 use crate::auth::{build_passthrough_headers_with_auth, resolve_local_openai_bearer_auth};
 use crate::policy::local_standard_transport_unsupported_reason_with_network;
-use crate::rules::apply_local_header_rules;
+use crate::rules::apply_local_header_rules_with_request_headers;
 use crate::snapshot::GatewayProviderTransportSnapshot;
 use crate::url::build_openai_responses_url;
 
@@ -59,12 +59,13 @@ pub fn build_openai_image_headers(
     );
     provider_request_headers.insert("content-type".to_string(), "application/json".to_string());
     provider_request_headers.insert("accept".to_string(), "text/event-stream".to_string());
-    if !apply_local_header_rules(
+    if !apply_local_header_rules_with_request_headers(
         &mut provider_request_headers,
         input.header_rules,
         &[input.auth_header, "content-type", "accept"],
         input.provider_request_body,
         Some(input.original_request_body),
+        Some(input.headers),
     ) {
         return None;
     }

crates/aether-provider-transport/src/same_format_provider.rs

@@ -18,7 +18,9 @@ use crate::policy::{
     local_gemini_transport_unsupported_reason_with_network,
     local_standard_transport_unsupported_reason_with_network,
 };
-use crate::rules::{apply_local_body_rules, apply_local_header_rules};
+use crate::rules::{
+    apply_local_body_rules_with_request_headers, apply_local_header_rules_with_request_headers,
+};
 use crate::snapshot::GatewayProviderTransportSnapshot;
 use crate::vertex::{
     is_vertex_api_key_transport_context,
@@ -57,6 +59,7 @@ pub struct SameFormatProviderRequestBodyInput<'a> {
     pub source_model: Option<&'a str>,
     pub family: SameFormatProviderFamily,
     pub body_rules: Option<&'a Value>,
+    pub request_headers: Option<&'a http::HeaderMap>,
     pub upstream_is_stream: bool,
     pub kiro_auth_config: Option<&'a KiroAuthConfig>,
     pub is_claude_code: bool,
@@ -131,6 +134,7 @@ pub fn build_same_format_provider_request_body(
             input.mapped_model,
             kiro_auth_config,
             input.body_rules,
+            input.request_headers,
         );
     }
 
@@ -183,10 +187,11 @@ pub fn build_same_format_provider_request_body(
             );
         }
     }
-    if !apply_local_body_rules(
+    if !apply_local_body_rules_with_request_headers(
         &mut provider_request_body,
         input.body_rules,
         Some(input.body_json),
+        input.request_headers,
     ) {
         return None;
     }
@@ -257,12 +262,13 @@ pub fn build_same_format_provider_headers(
         .filter(|value| !value.trim().is_empty())
         .map(|value| vec![value, "content-type"])
         .unwrap_or_else(|| vec!["content-type"]);
-    if !apply_local_header_rules(
+    if !apply_local_header_rules_with_request_headers(
         &mut provider_request_headers,
         input.header_rules,
         &protected_headers,
         input.provider_request_body,
         Some(input.original_request_body),
+        Some(input.headers),
     ) {
         return None;
     }
@@ -509,6 +515,7 @@ mod tests {
             source_model: Some("client-model"),
             family: SameFormatProviderFamily::Standard,
             body_rules: None,
+            request_headers: None,
             upstream_is_stream: true,
             kiro_auth_config: None,
             is_claude_code: false,
@@ -536,6 +543,7 @@ mod tests {
             body_rules: Some(&json!([
                 {"action":"set","path":"metadata.body_rule_seen","value":true}
             ])),
+            request_headers: None,
             upstream_is_stream: false,
             kiro_auth_config: None,
             is_claude_code: false,

crates/aether-provider-transport/src/standard.rs

@@ -6,7 +6,10 @@ use crate::auth::{
     build_claude_passthrough_headers, build_complete_passthrough_headers_with_auth,
     build_openai_passthrough_headers, build_passthrough_headers, ensure_upstream_auth_header,
 };
-use crate::rules::{apply_local_body_rules, apply_local_header_rules};
+use crate::rules::{
+    apply_local_body_rules, apply_local_body_rules_with_request_headers,
+    apply_local_header_rules_with_request_headers,
+};
 use crate::snapshot::GatewayProviderTransportSnapshot;
 use crate::url::{build_openai_chat_url, build_openai_responses_url};
 use crate::vertex::uses_vertex_api_key_query_auth;
@@ -157,6 +160,23 @@ pub fn apply_standard_provider_request_body_rules(
     Some(provider_request_body)
 }
 
+pub fn apply_standard_provider_request_body_rules_with_request_headers(
+    mut provider_request_body: Value,
+    body_rules: Option<&Value>,
+    original_request_body: &Value,
+    request_headers: &http::HeaderMap,
+) -> Option<Value> {
+    if !apply_local_body_rules_with_request_headers(
+        &mut provider_request_body,
+        body_rules,
+        Some(original_request_body),
+        Some(request_headers),
+    ) {
+        return None;
+    }
+    Some(provider_request_body)
+}
+
 pub fn build_standard_provider_request_headers(
     input: StandardProviderRequestHeadersInput<'_>,
 ) -> Option<StandardProviderRequestHeaders> {
@@ -193,12 +213,13 @@ pub fn build_standard_provider_request_headers(
     } else {
         &[input.auth_header, "content-type"][..]
     };
-    if !apply_local_header_rules(
+    if !apply_local_header_rules_with_request_headers(
         &mut headers,
         input.header_rules,
         protected_headers,
         input.provider_request_body,
         Some(input.original_request_body),
+        Some(input.headers),
     ) {
         return None;
     }

crates/aether-provider-transport/src/video.rs

@@ -17,7 +17,9 @@ use super::policy::{
     local_standard_transport_unsupported_reason_with_network, supports_local_gemini_transport,
     supports_local_standard_transport,
 };
-use super::rules::{apply_local_body_rules, apply_local_header_rules};
+use super::rules::{
+    apply_local_body_rules_with_request_headers, apply_local_header_rules_with_request_headers,
+};
 use super::snapshot::GatewayProviderTransportSnapshot;
 use super::url::{build_gemini_video_predict_long_running_url, build_passthrough_path_url};
 
@@ -117,6 +119,7 @@ pub fn build_video_create_request_body(
     family: ProviderVideoCreateFamily,
     mapped_model: &str,
     body_rules: Option<&Value>,
+    request_headers: Option<&http::HeaderMap>,
 ) -> Option<Value> {
     let mut provider_request_body = match family {
         ProviderVideoCreateFamily::OpenAi => {
@@ -127,7 +130,12 @@ pub fn build_video_create_request_body(
         }
         ProviderVideoCreateFamily::Gemini => body_json.clone(),
     };
-    if !apply_local_body_rules(&mut provider_request_body, body_rules, Some(body_json)) {
+    if !apply_local_body_rules_with_request_headers(
+        &mut provider_request_body,
+        body_rules,
+        Some(body_json),
+        request_headers,
+    ) {
         return None;
     }
     Some(provider_request_body)
@@ -184,12 +192,13 @@ pub fn build_video_create_headers(
         input.auth_value,
         &BTreeMap::new(),
     );
-    if !apply_local_header_rules(
+    if !apply_local_header_rules_with_request_headers(
         &mut provider_request_headers,
         input.header_rules,
         &[input.auth_header, "content-type"],
         input.provider_request_body,
         Some(input.original_request_body),
+        Some(input.headers),
     ) {
         return None;
     }
@@ -409,6 +418,7 @@ mod tests {
             ProviderVideoCreateFamily::OpenAi,
             "upstream-video-model",
             None,
+            None,
         )
         .expect("body should build");
 

frontend/src/api/endpoints/types/provider.ts

@@ -140,7 +140,7 @@ export interface BodyRuleConditionLeaf {
   path: string
   op: BodyRuleConditionOp
   value?: unknown  // exists / not_exists 不需要 value
-  source?: 'original' | 'current'
+  source?: 'request_headers'  // 不填表示请求体；填 request_headers 表示请求头
 }
 
 export interface BodyRuleConditionAll {

frontend/src/features/providers/components/EndpointConditionEditor.vue

@@ -127,17 +127,17 @@
           <SelectValue />
         </SelectTrigger>
         <SelectContent>
-          <SelectItem value="current">
+          <SelectItem value="body">
-            Current
+            请求体
           </SelectItem>
-          <SelectItem value="original">
+          <SelectItem value="request_headers">
-            Original
+            请求头
           </SelectItem>
         </SelectContent>
       </Select>
       <Input
         :model-value="modelValue.path"
-        :placeholder="pathHint || '字段路径'"
+        :placeholder="modelValue.source === 'request_headers' ? 'Header 名称' : (pathHint || '字段路径')"
         size="sm"
         class="flex-1 min-w-[120px] h-7 text-xs"
         @update:model-value="(value) => updateLeafField('path', value)"

frontend/src/features/providers/components/EndpointFormDialog.vue

@@ -635,14 +635,14 @@
                                 <code>in</code> 在列表中（值填 <code>["a","b"]</code>）<br>
                                 <code>type_is</code> 类型判断（string/number/boolean/array/object/null）<br>
                                 条件路径支持 <code>$item.xxx</code> 引用通配符当前元素<br>
-                                可切换 <code>Current</code>/<code>Original</code> 数据源，并支持 <code>ALL</code>/<code>ANY</code> 组合条件
+                                可切换 <code>请求体</code>/<code>请求头</code> 数据源，并支持 <code>ALL</code>/<code>ANY</code> 组合条件
                               </div>
                             </div>
                             <div class="text-muted-foreground">
-                              规则按顺序执行，前面的修改对后续规则可见。
+                              规则按顺序执行；条件判断使用客户端原始请求体或原始请求头，不受前面规则修改影响。
                             </div>
                             <div class="text-muted-foreground">
-                              规则默认在格式转换后按目标提供商结构匹配；条件切到 <code>Original</code> 时则按客户端原始请求体匹配。
+                              条件默认按客户端原始请求体匹配；切到 <code>请求头</code> 时按客户端原始请求头匹配。
                             </div>
                           </div>
                         </PopoverContent>
@@ -1484,8 +1484,8 @@ function validateJsonConditionShape(condition: Record<string, unknown>, label: s
   if (typeof condition.op !== 'string' || !CONDITION_JSON_OPS.has(condition.op)) {
     return `${label}.op 无效`
   }
-  if (condition.source !== undefined && condition.source !== 'original' && condition.source !== 'current') {
+  if (condition.source !== undefined && condition.source !== 'request_headers') {
-    return `${label}.source 只能是 original/current`
+    return `${label}.source 只能是 request_headers；请求体条件不要填写 source`
   }
   return null
 }

frontend/src/features/providers/components/endpoint-rule-condition.ts

@@ -1,6 +1,6 @@
 import type { BodyRuleCondition, BodyRuleConditionOp } from '@/api/endpoints'
 
-export type ConditionSource = 'current' | 'original'
+export type ConditionSource = 'body' | 'request_headers'
 export type ConditionGroupMode = 'all' | 'any'
 
 export interface EditableConditionLeaf {
@@ -46,7 +46,7 @@ export function createEmptyConditionLeaf(): EditableConditionLeaf {
     path: '',
     op: 'eq',
     value: '',
-    source: 'current',
+    source: 'body',
   }
 }
 
@@ -86,6 +86,7 @@ export function conditionToEditable(condition?: BodyRuleCondition | null): Edita
       condition.any.map(child => conditionToEditable(child) || createEmptyConditionLeaf()),
     )
   }
+  const source = (condition as { source?: unknown }).source
   return {
     kind: 'leaf',
     path: condition.path || '',
@@ -93,7 +94,9 @@ export function conditionToEditable(condition?: BodyRuleCondition | null): Edita
     value: condition.value !== undefined
       ? (typeof condition.value === 'string' ? condition.value : JSON.stringify(condition.value))
       : '',
-    source: condition.source === 'original' ? 'original' : 'current',
+    source: source === 'request_headers' || source === 'headers'
+        ? 'request_headers'
+        : 'body',
   }
 }
 
@@ -114,7 +117,7 @@ export function editableConditionToApi(node: EditableConditionNode | null): Body
   const base = {
     path,
     op: node.op,
-    ...(node.source === 'original' ? { source: 'original' as const } : {}),
+    ...(node.source === 'request_headers' ? { source: 'request_headers' as const } : {}),
   }
 
   if (node.op === 'exists' || node.op === 'not_exists') {