diff --git a/lexicon/com.ponderants.node.json b/lexicon/com.ponderants.node.json
new file mode 100644
index 0000000..a6a2677
--- /dev/null
+++ b/lexicon/com.ponderants.node.json
@@ -0,0 +1,39 @@
+{
+  "lexicon": 1,
+  "id": "com.ponderants.node",
+  "defs": {
+    "main": {
+      "type": "record",
+      "description": "A Ponderants thought node. It represents a single, captured idea, intended to be linked to other nodes to form a 'thought galaxy'.",
+      "record": {
+        "type": "object",
+        "required": ["createdAt", "title", "body"],
+        "properties": {
+          "createdAt": {
+            "type": "string",
+            "format": "datetime"
+          },
+          "title": {
+            "type": "string",
+            "maxLength": 256,
+            "description": "The title of the thought node."
+          },
+          "body": {
+            "type": "string",
+            "maxLength": 3000,
+            "description": "The main content of the thought node, often generated by the AI interviewer."
+          },
+          "links": {
+            "type": "array",
+            "description": "An array of AT-URIs (as strong refs) pointing to other nodes this node is linked to.",
+            "items": {
+              "type": "string",
+              "format": "at-uri"
+            },
+            "maxLength": 50
+          }
+        }
+      }
+    }
+  }
+}