diff --git a/AGENTS.md b/AGENTS.md
index 08f3e77..dceba87 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -106,7 +106,7 @@ The server keeps the browser single-origin: `space.polymodel.*` reads are served
 
 - Investigate code and docs before asking factual questions.
 - Ask the operator for product intent and workflow tradeoffs.
-- Keep Jira updated at workflow gates. When adding Jira comments with restricted visibility through Atlassian MCP tools, use role visibility `{ "type": "role", "value": "Member" }`.
+- Keep Jira updated at workflow gates. Do not restrict comment visibility — leave comments visible to all.
 
 ## Code style
 
diff --git a/lexicons/library/getPartFile.json b/lexicons/library/getPartFile.json
new file mode 100644
index 0000000..6e1cc1f
--- /dev/null
+++ b/lexicons/library/getPartFile.json
@@ -0,0 +1,20 @@
+{
+  "lexicon": 1,
+  "id": "space.polymodel.library.getPartFile",
+  "defs": {
+    "main": {
+      "type": "query",
+      "description": "Fetch and reassemble a part's chunked geometry file into its original bytes. Returns the reconstructed file with its declared MIME type and a safe filename.",
+      "parameters": {
+        "type": "params",
+        "required": ["uri"],
+        "properties": {
+          "uri": { "type": "string", "format": "at-uri" }
+        }
+      },
+      "output": {
+        "encoding": "*/*"
+      }
+    }
+  }
+}