diff --git a/.claude/skills/build-plugin/SKILL.md b/.claude/skills/build-plugin/SKILL.md
index d508a63..07ba681 100644
--- a/.claude/skills/build-plugin/SKILL.md
+++ b/.claude/skills/build-plugin/SKILL.md
@@ -188,6 +188,8 @@ my-plugin/
       myStream.json
       scripts/
         myScript.js
+        errorHandling/
+          myStream.js          # errorHandling scripts referenced by path, like postRequestScript
     defaultContent/
       manifest.json
       scopes.json
diff --git a/.claude/skills/build-plugin/references/data-streams.md b/.claude/skills/build-plugin/references/data-streams.md
index 8c220cd..e94a2a9 100644
--- a/.claude/skills/build-plugin/references/data-streams.md
+++ b/.claude/skills/build-plugin/references/data-streams.md
@@ -476,7 +476,19 @@ The `paging` block in `config` controls how SquaredUp fetches multiple pages.
 "errorHandling": { "type": "path", "realm": "payload", "path": "error.message" }
 
 // Custom script — access response (.status, .body) and data
-"errorHandling": { "type": "script", "script": "result = response.status + ': ' + data.error;" }
+"errorHandling": { "type": "script", "script": "errorHandling/incidents.js" }
+```
+
+### Script files
+
+Reference the script as a file — the same mechanism [`postRequestScript`](#post-request-scripts) uses. Place the file in `dataStreams/scripts/errorHandling/`, named after the stream's `name` field, and set `script` to its path relative to `dataStreams/scripts/` — **the `.js` extension is required** (a bare `.js` path with no newline is what marks the value as a file reference; deploy inlines the file's source, and an unresolvable reference is a validation error).
+
+Script file (`dataStreams/scripts/errorHandling/incidents.js`) — `{{ ... }}` expressions work in script files too:
+
+```javascript
+const apiMsg = data && (data.message || data.error);
+
+result = apiMsg || ('Request failed with HTTP ' + response.status);
 ```
 
 ---
@@ -736,7 +748,7 @@ Scripts run after the HTTP response is received. Input is `data` (parsed JSON bo
 
 ### Wiring a script to a stream
 
-Set `postRequestScript` inside `config` to the script's filename — **the `.js` extension is required**. Name the file after the stream's `name` field and place it in `dataStreams/scripts/`.
+Set `postRequestScript` inside `config` to the script's filename — **the `.js` extension is required**. Name the file after the stream's `name` field and place it in `dataStreams/scripts/`. ([errorHandling scripts](#errorhandling) use the same file-reference mechanism, from the `errorHandling/` sub-folder.)
 
 Stream JSON (`dataStreams/incidents.json`):