diff --git a/crates/tinydocs-bus/src/spec/presentation/mod.rs b/crates/tinydocs-bus/src/spec/presentation/mod.rs
index da1deb4..d2705d1 100644
--- a/crates/tinydocs-bus/src/spec/presentation/mod.rs
+++ b/crates/tinydocs-bus/src/spec/presentation/mod.rs
@@ -104,6 +104,27 @@ pub struct SlideSpec {
 }
 
 impl SlideSpec {
+    /// Builds a slide from its text fields and already-resolved images.
+    ///
+    /// Hosts resolve their own image sources (artifacts, workspace files)
+    /// under their own policy and hand the contract only the bytes.
+    #[must_use]
+    pub fn new(
+        title: impl Into<String>,
+        body: Option<String>,
+        bullets: Vec<String>,
+        speaker_notes: Option<String>,
+        images: Vec<SlideImage>,
+    ) -> Self {
+        Self {
+            title: title.into(),
+            body,
+            bullets,
+            speaker_notes,
+            images,
+        }
+    }
+
     /// Returns `true` when the slide carries no renderable text at all — the
     /// title, body, and every bullet are absent or blank.
     ///
diff --git a/crates/tinydocs-bus/src/spec/presentation/mod_tests.rs b/crates/tinydocs-bus/src/spec/presentation/mod_tests.rs
index 9f24add..5832ee9 100644
--- a/crates/tinydocs-bus/src/spec/presentation/mod_tests.rs
+++ b/crates/tinydocs-bus/src/spec/presentation/mod_tests.rs
@@ -316,3 +316,46 @@ fn spec_defaults_optional_fields() {
     assert_eq!(s.theme, None);
     assert_eq!(s.slides.len(), 0);
 }
+
+#[test]
+fn slide_spec_new_matches_literal_and_pins_wire_shape() {
+    let image = SlideImage {
+        bytes: vec![1, 2, 3],
+        format: ImageFormat::Png,
+        width_px: 4,
+        height_px: 5,
+        caption: Some("cap".to_string()),
+    };
+    let built = SlideSpec::new(
+        "T",
+        Some("B".to_string()),
+        vec!["x".to_string()],
+        Some("N".to_string()),
+        vec![image.clone()],
+    );
+    let literal = SlideSpec {
+        title: "T".to_string(),
+        body: Some("B".to_string()),
+        bullets: vec!["x".to_string()],
+        speaker_notes: Some("N".to_string()),
+        images: vec![image],
+    };
+    assert_eq!(built, literal);
+    let value = serde_json::to_value(&built).unwrap();
+    let obj = value.as_object().unwrap();
+    let mut keys: Vec<_> = obj.keys().map(String::as_str).collect();
+    keys.sort_unstable();
+    assert_eq!(
+        keys,
+        ["body", "bullets", "images", "speaker_notes", "title"]
+    );
+    let img = value["images"][0].as_object().unwrap();
+    let mut ikeys: Vec<_> = img.keys().map(String::as_str).collect();
+    ikeys.sort_unstable();
+    assert_eq!(
+        ikeys,
+        ["bytes", "caption", "format", "height_px", "width_px"]
+    );
+    let back: SlideSpec = serde_json::from_value(value).unwrap();
+    assert_eq!(back, built);
+}