fix(mem0-plugin): thread cwd to resolvers, add write-path tests, userConfig for API key

- on_pre_compact.py and capture_compact_summary.py now read cwd from
  hook stdin and pass it to resolve_project_id/resolve_branch (monorepo safe)
- 5 new tests verify all write functions use app_id top-level and never
  put project_id in metadata
- plugin.json declares userConfig.MEM0_API_KEY so Claude Code prompts
  for the key at install time (sensitive, stored in system keychain)

mem0-plugin/.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "mem0",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "Mem0 memory layer for AI applications. Add persistent memory, personalization, and semantic search to Claude workflows using the Mem0 Platform MCP server.",
   "author": {
     "name": "Mem0",
@@ -9,5 +9,12 @@
   "homepage": "https://mem0.ai",
   "repository": "https://github.com/mem0ai/mem0",
   "license": "Apache-2.0",
-  "keywords": ["memory", "personalization", "mcp", "semantic-search"]
+  "keywords": ["memory", "personalization", "mcp", "semantic-search"],
+  "userConfig": {
+    "MEM0_API_KEY": {
+      "description": "Your Mem0 API key (get one at https://app.mem0.ai/dashboard/api-keys or run: mem0 init --agent --json)",
+      "required": true,
+      "sensitive": true
+    }
+  }
 }

mem0-plugin/scripts/capture_compact_summary.py

@@ -153,9 +153,10 @@ def main():
         return
 
     session_id = hook_input.get("session_id", "")
+    cwd = hook_input.get("cwd") or None
     user_id = resolve_user_id()
-    project_id = resolve_project_id()
-    branch = resolve_branch()
+    project_id = resolve_project_id(cwd)
+    branch = resolve_branch(cwd)
 
     lines = tail_lines(transcript_path, MAX_TAIL_LINES)
     if not lines:

mem0-plugin/scripts/on_pre_compact.py

@@ -234,9 +234,10 @@ def main():
         return
 
     session_id = hook_input.get("session_id", "")
+    cwd = hook_input.get("cwd") or None
     user_id = resolve_user_id()
-    project_id = resolve_project_id()
-    branch = resolve_branch()
+    project_id = resolve_project_id(cwd)
+    branch = resolve_branch(cwd)
 
     lines = tail_lines(transcript_path, MAX_TAIL_LINES)
     if not lines:

mem0-plugin/tests/test_write_path.py

@@ -0,0 +1,166 @@
+"""Tests for write-path app_id migration.
+
+Verifies that all scripts writing to the Mem0 API:
+1. Pass app_id as a top-level parameter (not in metadata)
+2. Do NOT include project_id in metadata
+3. Include branch in metadata when available
+"""
+
+from __future__ import annotations
+
+import json
+from unittest.mock import MagicMock, patch
+
+
+def test_auto_import_post_memory_uses_app_id():
+    """auto_import.post_memory sends app_id top-level, not metadata.project_id."""
+    from auto_import import post_memory
+
+    captured = {}
+
+    def mock_urlopen(req, timeout=None):
+        body = json.loads(req.data.decode("utf-8"))
+        captured.update(body)
+        resp = MagicMock()
+        resp.status = 200
+        resp.__enter__ = lambda s: s
+        resp.__exit__ = MagicMock(return_value=False)
+        return resp
+
+    with patch("urllib.request.urlopen", side_effect=mock_urlopen):
+        result = post_memory(
+            api_key="test-key",
+            content="test content",
+            user_id="testuser",
+            filename="CLAUDE.md",
+            project_id="my-project",
+            branch="main",
+        )
+
+    assert result is True
+    assert captured["app_id"] == "my-project"
+    assert captured["user_id"] == "testuser"
+    assert "project_id" not in captured.get("metadata", {})
+    assert captured["metadata"]["type"] == "project_profile"
+    assert captured["metadata"]["branch"] == "main"
+    assert captured["infer"] is False
+
+
+def test_auto_import_post_memory_omits_empty_branch():
+    """auto_import.post_memory skips branch in metadata when empty."""
+    from auto_import import post_memory
+
+    captured = {}
+
+    def mock_urlopen(req, timeout=None):
+        body = json.loads(req.data.decode("utf-8"))
+        captured.update(body)
+        resp = MagicMock()
+        resp.status = 200
+        resp.__enter__ = lambda s: s
+        resp.__exit__ = MagicMock(return_value=False)
+        return resp
+
+    with patch("urllib.request.urlopen", side_effect=mock_urlopen):
+        post_memory("key", "content", "user", "FILE.md", "proj", branch="")
+
+    assert "branch" not in captured.get("metadata", {})
+
+
+def test_on_pre_compact_store_memory_uses_app_id():
+    """on_pre_compact.store_memory sends app_id top-level."""
+    from on_pre_compact import store_memory
+
+    captured = {}
+
+    def mock_urlopen(req, timeout=None):
+        body = json.loads(req.data.decode("utf-8"))
+        captured.update(body)
+        resp = MagicMock()
+        resp.status = 200
+        resp.__enter__ = lambda s: s
+        resp.__exit__ = MagicMock(return_value=False)
+        return resp
+
+    with patch("urllib.request.urlopen", side_effect=mock_urlopen):
+        result = store_memory(
+            api_key="test-key",
+            content="session state content",
+            user_id="testuser",
+            source="pre-compaction",
+            session_id="sess-123",
+            project_id="my-project",
+            branch="feat/auth",
+        )
+
+    assert result is True
+    assert captured["app_id"] == "my-project"
+    assert captured["user_id"] == "testuser"
+    assert "project_id" not in captured.get("metadata", {})
+    assert captured["metadata"]["type"] == "session_state"
+    assert captured["metadata"]["source"] == "pre-compaction"
+    assert captured["metadata"]["branch"] == "feat/auth"
+    assert "expiration_date" in captured
+
+
+def test_capture_compact_summary_store_uses_app_id():
+    """capture_compact_summary.store_summary sends app_id top-level."""
+    from capture_compact_summary import store_summary
+
+    captured = {}
+
+    def mock_urlopen(req, timeout=None):
+        body = json.loads(req.data.decode("utf-8"))
+        captured.update(body)
+        resp = MagicMock()
+        resp.status = 200
+        resp.__enter__ = lambda s: s
+        resp.__exit__ = MagicMock(return_value=False)
+        return resp
+
+    with patch("urllib.request.urlopen", side_effect=mock_urlopen):
+        result = store_summary(
+            api_key="test-key",
+            summary="compact summary text",
+            user_id="testuser",
+            session_id="sess-456",
+            project_id="my-project",
+            branch="main",
+        )
+
+    assert result is True
+    assert captured["app_id"] == "my-project"
+    assert captured["user_id"] == "testuser"
+    assert "project_id" not in captured.get("metadata", {})
+    assert captured["metadata"]["type"] == "compact_summary"
+    assert captured["metadata"]["branch"] == "main"
+    assert captured["infer"] is False
+    assert "expiration_date" in captured
+
+
+def test_no_metadata_project_id_anywhere():
+    """Ensure none of the write functions put project_id in metadata."""
+    from auto_import import post_memory
+    from capture_compact_summary import store_summary
+    from on_pre_compact import store_memory
+
+    bodies = []
+
+    def mock_urlopen(req, timeout=None):
+        body = json.loads(req.data.decode("utf-8"))
+        bodies.append(body)
+        resp = MagicMock()
+        resp.status = 200
+        resp.__enter__ = lambda s: s
+        resp.__exit__ = MagicMock(return_value=False)
+        return resp
+
+    with patch("urllib.request.urlopen", side_effect=mock_urlopen):
+        post_memory("k", "c", "u", "f", "proj", "br")
+        store_memory("k", "c", "u", "src", "sid", "proj", "br")
+        store_summary("k", "s", "u", "sid", "proj", "br")
+
+    for i, body in enumerate(bodies):
+        metadata = body.get("metadata", {})
+        assert "project_id" not in metadata, f"Write function #{i} still has metadata.project_id"
+        assert body.get("app_id") == "proj", f"Write function #{i} missing app_id top-level"