diff --git a/core/crates/solstone-core-convey-http/Cargo.toml b/core/crates/solstone-core-convey-http/Cargo.toml
index ea26de9d6..386797e56 100644
--- a/core/crates/solstone-core-convey-http/Cargo.toml
+++ b/core/crates/solstone-core-convey-http/Cargo.toml
@@ -14,5 +14,6 @@ axum.workspace = true
 hyper.workspace = true
 hyper-util.workspace = true
 serde.workspace = true
+serde_json.workspace = true
 tokio = { workspace = true, features = ["net", "io-util", "rt", "rt-multi-thread", "macros"] }
 tower-http.workspace = true
diff --git a/core/crates/solstone-core-convey-http/src/lib.rs b/core/crates/solstone-core-convey-http/src/lib.rs
index 700d8a40d..33ad28594 100644
--- a/core/crates/solstone-core-convey-http/src/lib.rs
+++ b/core/crates/solstone-core-convey-http/src/lib.rs
@@ -146,4 +146,5 @@ pub mod envelope;
 pub mod gate;
 pub mod identity;
 pub mod listener;
+pub mod refusal;
 pub mod serve;
diff --git a/core/crates/solstone-core-convey-http/src/refusal.rs b/core/crates/solstone-core-convey-http/src/refusal.rs
new file mode 100644
index 000000000..7cad81b98
--- /dev/null
+++ b/core/crates/solstone-core-convey-http/src/refusal.rs
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright (c) 2026 sol pbc
+
+//! Repair-required refusal payloads shared with the Python entity operations.
+
+use serde::Serialize;
+use serde_json::Value;
+
+use crate::envelope::ErrorEnvelope;
+
+/// A merge refusal that leaves durable state requiring manual repair.
+#[derive(Debug, Serialize)]
+pub struct MergeRepairRequired {
+    #[serde(flatten)]
+    pub envelope: ErrorEnvelope,
+    pub failed_phase: String,
+    pub source_id: String,
+    pub target_id: String,
+    pub operation_state: String,
+    pub mutation_applied: bool,
+    pub source_state: Value,
+    pub target_state: Value,
+    pub safe_remediation: String,
+}
+
+/// An undo refusal that leaves durable state requiring manual repair.
+#[derive(Debug, Serialize)]
+pub struct UndoRepairRequired {
+    #[serde(flatten)]
+    pub envelope: ErrorEnvelope,
+    pub merge_id: String,
+    pub source_id: String,
+    pub target_id: String,
+    pub operation_state: String,
+    pub mutation_applied: bool,
+    pub source_state: Value,
+    pub target_state: Value,
+    pub safe_remediation: String,
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::BTreeSet;
+
+    use serde_json::{Value, json, to_value};
+
+    use super::{MergeRepairRequired, UndoRepairRequired};
+    use crate::envelope::ErrorEnvelope;
+
+    fn envelope() -> ErrorEnvelope {
+        ErrorEnvelope {
+            error: "Conflict".to_owned(),
+            reason_code: "repair_required".to_owned(),
+            detail: "repair needed".to_owned(),
+        }
+    }
+
+    fn merge() -> MergeRepairRequired {
+        MergeRepairRequired {
+            envelope: envelope(),
+            failed_phase: "commit".to_owned(),
+            source_id: "source".to_owned(),
+            target_id: "target".to_owned(),
+            operation_state: "partially_applied".to_owned(),
+            mutation_applied: true,
+            source_state: json!({"id": "source"}),
+            target_state: json!({"id": "target"}),
+            safe_remediation: "repair manually".to_owned(),
+        }
+    }
+
+    fn undo() -> UndoRepairRequired {
+        UndoRepairRequired {
+            envelope: envelope(),
+            merge_id: "merge-1".to_owned(),
+            source_id: "source".to_owned(),
+            target_id: "target".to_owned(),
+            operation_state: "partially_undone".to_owned(),
+            mutation_applied: true,
+            source_state: json!({"id": "source"}),
+            target_state: json!({"id": "target"}),
+            safe_remediation: "repair manually".to_owned(),
+        }
+    }
+
+    fn keys(value: &Value) -> BTreeSet<String> {
+        value
+            .as_object()
+            .expect("repair refusal serializes as an object")
+            .keys()
+            .cloned()
+            .collect()
+    }
+
+    #[test]
+    fn repair_refusals_flatten_exactly_eleven_top_level_keys() {
+        let merge_keys = keys(&to_value(merge()).unwrap());
+        let undo_keys = keys(&to_value(undo()).unwrap());
+
+        assert_eq!(
+            merge_keys,
+            BTreeSet::from([
+                "detail".to_owned(),
+                "error".to_owned(),
+                "failed_phase".to_owned(),
+                "mutation_applied".to_owned(),
+                "operation_state".to_owned(),
+                "reason_code".to_owned(),
+                "safe_remediation".to_owned(),
+                "source_id".to_owned(),
+                "source_state".to_owned(),
+                "target_id".to_owned(),
+                "target_state".to_owned(),
+            ])
+        );
+        assert_eq!(
+            undo_keys,
+            BTreeSet::from([
+                "detail".to_owned(),
+                "error".to_owned(),
+                "merge_id".to_owned(),
+                "mutation_applied".to_owned(),
+                "operation_state".to_owned(),
+                "reason_code".to_owned(),
+                "safe_remediation".to_owned(),
+                "source_id".to_owned(),
+                "source_state".to_owned(),
+                "target_id".to_owned(),
+                "target_state".to_owned(),
+            ])
+        );
+    }
+
+    #[test]
+    fn repair_refusal_variants_cannot_carry_both_variant_keys() {
+        let merge_keys = keys(&to_value(merge()).unwrap());
+        let undo_keys = keys(&to_value(undo()).unwrap());
+        let differing: BTreeSet<_> = merge_keys
+            .symmetric_difference(&undo_keys)
+            .cloned()
+            .collect();
+
+        assert_eq!(
+            differing,
+            BTreeSet::from(["failed_phase".to_owned(), "merge_id".to_owned()])
+        );
+        assert!(!merge_keys.contains("merge_id") && !undo_keys.contains("failed_phase"));
+    }
+}