fix(plugins): report the plugin that produced the event, not the one that sent it (#7323)

integrations/agent-plugin-core/build/build.py

@@ -81,6 +81,28 @@ def replace_output(staged: Path, output: Path) -> Path:
     return output
 
 
+def _render_harness_id(host: str) -> str:
+    """Emit core/_harness_id.py for one host.
+
+    Carries both vocabularies from a single definition: the PostHog `source` tag
+    and the platform's X-Mem0-Source / X-Application pair. Keeping them together
+    is what stops the two from drifting into separate vocabularies for the same
+    thing.
+    """
+    tag = host.upper().replace("-", "_") + "_PLUGIN"
+    return (
+        '"""Generated by integrations/agent-plugin-core/build/build.py. Do not edit."""\n'
+        "\n"
+        f'HARNESS_ID = "{host}"\n'
+        f'SOURCE_TAG = "{tag}"\n'
+        "\n"
+        "# Platform-side vocabulary (mem0_event.source + X-Application). The whole\n"
+        "# plugin family is one source; which editor it runs in is the application.\n"
+        'PLATFORM_SOURCE = "MEM0_PLUGIN"\n'
+        f'PLATFORM_APPLICATION = "{host}"\n'
+    )
+
+
 def _bundle_python(
     staged: Path,
     host: str,
@@ -96,6 +118,12 @@ def _bundle_python(
             continue
         shutil.copy2(source, core / source.name)
 
+    # Generated per host so identity does not depend on an entrypoint remembering
+    # to call telemetry.init(). mcp_server.py and the detached telemetry.py sender
+    # never did, which is how MCP searches reported harness=generic and every
+    # batch they drained was labelled MEM0_PLUGIN regardless of the real host.
+    (core / "_harness_id.py").write_text(_render_harness_id(host), encoding="utf-8")
+
     values = {
         "PLUGIN_ROOT": plugin_root,
         "PLUGIN_DATA": "${PLUGIN_DATA}",