diff --git a/packages/coding-agent/src/core/tools/edit-diff.ts b/packages/coding-agent/src/core/tools/edit-diff.ts
index f280bf19..cc94c202 100644
--- a/packages/coding-agent/src/core/tools/edit-diff.ts
+++ b/packages/coding-agent/src/core/tools/edit-diff.ts
@@ -1,6 +1,5 @@
 /**
- * Shared diff computation utilities for the edit tool.
- * Used by both edit.ts (for execution) and tool-execution.ts (for preview rendering).
+ * Shared diff computation utilities for the edit and similar tools.
  */
 
 import * as Diff from "diff";
diff --git a/packages/coding-agent/src/index.ts b/packages/coding-agent/src/index.ts
index 70416af1..5830ecda 100644
--- a/packages/coding-agent/src/index.ts
+++ b/packages/coding-agent/src/index.ts
@@ -246,6 +246,7 @@ export {
 	type SkillFrontmatter,
 } from "./core/skills.ts";
 export { createSyntheticSourceInfo } from "./core/source-info.ts";
+export { type EditDiffResult, generateDiffString, generateUnifiedPatch } from "./core/tools/edit-diff.ts";
 // Tools
 export {
 	type BashOperations,