diff --git a/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/cost/video/omni_gen_video_cost_handler.rs b/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/cost/video/omni_gen_video_cost_handler.rs
index 479e692b79..b9b697eb0c 100644
--- a/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/cost/video/omni_gen_video_cost_handler.rs
+++ b/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/cost/video/omni_gen_video_cost_handler.rs
@@ -8,6 +8,7 @@ use artcraft_router::api::router_provider::RouterProvider;
 use log::warn;
 use crate::http_server::common_responses::common_web_error::CommonWebError;
 use crate::http_server::endpoints::omni_gen::generate::video::helpers::hydrate_router_request::hydrate_to_router_request;
+use crate::http_server::endpoints::omni_gen::generate::video::helpers::validate_image_required::validate_image_required;
 use crate::state::server_state::ServerState;
 
 /// Estimate the cost of a video generation.
@@ -27,6 +28,8 @@ pub async fn omni_gen_video_cost_handler(
   request: Json<OmniGenVideoCostAndGenerateRequest>,
   _server_state: web::Data<Arc<ServerState>>,
 ) -> Result<Json<OmniGenVideoCostResponse>, CommonWebError> {
+  validate_image_required(&request)?;
+
   let mut builder = hydrate_to_router_request(&request)?;
 
   builder.provider = RouterProvider::Artcraft;
diff --git a/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/helpers/mod.rs b/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/helpers/mod.rs
index 7108f22a3b..2c80241f67 100644
--- a/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/helpers/mod.rs
+++ b/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/helpers/mod.rs
@@ -4,3 +4,4 @@ pub(crate) mod hydrate_router_request;
 pub mod pipeline_result;
 pub mod resolve_kinovi_character_ids;
 pub mod resolve_media_tokens_to_urls;
+pub mod validate_image_required;
diff --git a/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/helpers/validate_image_required.rs b/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/helpers/validate_image_required.rs
new file mode 100644
index 0000000000..f56e4e1d7f
--- /dev/null
+++ b/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/helpers/validate_image_required.rs
@@ -0,0 +1,156 @@
+use artcraft_api_defs::omni_gen::cost_and_generate_requests::omni_gen_video_cost_and_generate_request::OmniGenVideoCostAndGenerateRequest;
+use enums::common::generation::common_video_model::CommonVideoModel;
+
+use crate::http_server::common_responses::common_web_error::CommonWebError;
+
+/// xAI's `grok-imagine-video-1.5-preview` model rejects text-to-video at
+/// the upstream API. Reject the request at the handler layer so callers see
+/// a clean 400 with an actionable message and we don't charge their wallet
+/// for an inference job we know will fail.
+pub fn validate_image_required(
+  request: &OmniGenVideoCostAndGenerateRequest,
+) -> Result<(), CommonWebError> {
+  match request.model {
+    Some(CommonVideoModel::GrokImagineVideo1p5) => {}, // Fall-through
+    _ => return Ok(()),
+  }
+
+  let requires_image = matches!(request.model, Some(CommonVideoModel::GrokImagineVideo1p5));
+
+  if !requires_image {
+    return Ok(());
+  }
+
+  let has_start_frame = request.start_frame_image_media_token.is_some();
+  let has_reference_images = request
+    .reference_image_media_tokens
+    .as_ref()
+    .is_some_and(|v| !v.is_empty());
+
+  if has_start_frame || has_reference_images {
+    return Ok(());
+  }
+
+  Err(CommonWebError::BadInputWithSimpleMessage(
+    "Image is required".to_string(),
+  ))
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use tokens::tokens::media_files::MediaFileToken;
+
+  fn base_request() -> OmniGenVideoCostAndGenerateRequest {
+    OmniGenVideoCostAndGenerateRequest {
+      idempotency_token: Some("a1b2c3d4-e5f6-7890-abcd-ef1234567890".to_string()),
+      model: None,
+      prompt: Some("test".to_string()),
+      negative_prompt: None,
+      start_frame_image_media_token: None,
+      end_frame_image_media_token: None,
+      reference_image_media_tokens: None,
+      reference_video_media_tokens: None,
+      reference_audio_media_tokens: None,
+      reference_character_tokens: None,
+      resolution: None,
+      aspect_ratio: None,
+      quality: None,
+      duration_seconds: Some(5),
+      video_batch_count: Some(1),
+      generate_audio: None,
+    }
+  }
+
+  fn token(id: &str) -> MediaFileToken {
+    MediaFileToken::new(id.to_string())
+  }
+
+  #[test]
+  fn passes_when_model_is_none() {
+    let req = base_request();
+    assert!(validate_image_required(&req).is_ok());
+  }
+
+  #[test]
+  fn passes_for_other_models_without_image() {
+    // Only v1.5 needs the gate; other models can do text-to-video.
+    let req = OmniGenVideoCostAndGenerateRequest {
+      model: Some(CommonVideoModel::Seedance2p0),
+      ..base_request()
+    };
+    assert!(validate_image_required(&req).is_ok());
+  }
+
+  #[test]
+  fn rejects_v1p5_with_no_image_inputs() {
+    let req = OmniGenVideoCostAndGenerateRequest {
+      model: Some(CommonVideoModel::GrokImagineVideo1p5),
+      ..base_request()
+    };
+    let err = validate_image_required(&req).expect_err("should reject");
+    match err {
+      CommonWebError::BadInputWithSimpleMessage(msg) => {
+        assert_eq!(msg, "Image is required");
+      }
+      other => panic!("expected BadInputWithSimpleMessage, got {:?}", other),
+    }
+  }
+
+  #[test]
+  fn rejects_v1p5_with_empty_reference_list_and_no_start_frame() {
+    let req = OmniGenVideoCostAndGenerateRequest {
+      model: Some(CommonVideoModel::GrokImagineVideo1p5),
+      reference_image_media_tokens: Some(vec![]),
+      ..base_request()
+    };
+    assert!(matches!(
+      validate_image_required(&req),
+      Err(CommonWebError::BadInputWithSimpleMessage(_))
+    ));
+  }
+
+  #[test]
+  fn accepts_v1p5_with_start_frame_only() {
+    let req = OmniGenVideoCostAndGenerateRequest {
+      model: Some(CommonVideoModel::GrokImagineVideo1p5),
+      start_frame_image_media_token: Some(token("mf_start")),
+      ..base_request()
+    };
+    assert!(validate_image_required(&req).is_ok());
+  }
+
+  #[test]
+  fn accepts_v1p5_with_reference_images_only() {
+    let req = OmniGenVideoCostAndGenerateRequest {
+      model: Some(CommonVideoModel::GrokImagineVideo1p5),
+      reference_image_media_tokens: Some(vec![token("mf_a"), token("mf_b")]),
+      ..base_request()
+    };
+    assert!(validate_image_required(&req).is_ok());
+  }
+
+  #[test]
+  fn accepts_v1p5_with_both_start_frame_and_reference_images() {
+    let req = OmniGenVideoCostAndGenerateRequest {
+      model: Some(CommonVideoModel::GrokImagineVideo1p5),
+      start_frame_image_media_token: Some(token("mf_start")),
+      reference_image_media_tokens: Some(vec![token("mf_a")]),
+      ..base_request()
+    };
+    assert!(validate_image_required(&req).is_ok());
+  }
+
+  #[test]
+  fn end_frame_alone_does_not_count_as_image_input() {
+    // end_frame_image_media_token is technically an image, but xAI's v1.5
+    // wire shape only uses start_frame / reference_images. end_frame
+    // shouldn't satisfy the gate.
+    let req = OmniGenVideoCostAndGenerateRequest {
+      model: Some(CommonVideoModel::GrokImagineVideo1p5),
+      end_frame_image_media_token: Some(token("mf_end")),
+      ..base_request()
+    };
+    assert!(validate_image_required(&req).is_err());
+  }
+}
diff --git a/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/omni_gen_video_generate_handler.rs b/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/omni_gen_video_generate_handler.rs
index feab9a3dd8..96a6b6535b 100644
--- a/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/omni_gen_video_generate_handler.rs
+++ b/crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/omni_gen_video_generate_handler.rs
@@ -32,6 +32,7 @@ use tokens::tokens::non_unique::debug_logs_event_token::DebugLogEventToken;
 use crate::http_server::common_responses::common_web_error::CommonWebError;
 use crate::http_server::endpoints::generate::common::payments_error_test::payments_error_test;
 use crate::http_server::endpoints::omni_gen::generate::video::helpers::hydrate_router_request::hydrate_to_router_request;
+use crate::http_server::endpoints::omni_gen::generate::video::helpers::validate_image_required::validate_image_required;
 use crate::http_server::endpoints::omni_gen::generate::video::insert_db_job::insert_fal_job::{insert_fal_job, InsertFalJobArgs};
 use crate::http_server::endpoints::omni_gen::generate::video::insert_db_job::insert_gmicloud_job::{insert_gmicloud_job, InsertGmiCloudJobArgs};
 use crate::http_server::endpoints::omni_gen::generate::video::insert_db_job::insert_grok_api_job::{insert_grok_api_job, InsertGrokApiJobArgs};
@@ -67,6 +68,10 @@ pub async fn omni_gen_video_generate_handler(
 
   info!("request: {:?}", request);
 
+  // Reject doomed combos (e.g. grok_imagine_video_1p5 without an image)
+  // before any billable or DB-mutating work — see helper for the rules.
+  validate_image_required(&request)?;
+
   payments_error_test(&request.prompt.as_deref().unwrap_or(""))?;
 
   let debug_log_event_token = DebugLogEventToken::generate();