feat: session prompt, clipboard fix, output batching, and dep cleanup

README.md

@@ -301,7 +301,7 @@ Production uses `workers=1` (PTY state is process-local), `threads=16` (concurre
 <summary><strong>📁 Project Structure</strong></summary>
 
 ```
-coding-agents-in-databricks/
+coding-agents-databricks-apps/
 ├── app.py                       # Flask backend + PTY management + setup orchestration
 ├── app_state.py                 # Shared app state (setup progress, session registry)
 ├── app.yaml.template            # Databricks Apps deployment config template

app.py

@@ -43,6 +43,7 @@
 SESSION_TIMEOUT_SECONDS = 86400      # No poll for 24 hours = dead session
 CLEANUP_INTERVAL_SECONDS = 900       # Check for stale sessions every 15 min
 GRACEFUL_SHUTDOWN_WAIT = 3          # Seconds to wait after SIGHUP before SIGKILL
+MAX_CONCURRENT_SESSIONS = int(os.environ.get("MAX_CONCURRENT_SESSIONS", "5"))
 
 # Logging setup
 logging.basicConfig(level=logging.INFO)
@@ -604,7 +605,7 @@ def read_pty_output(session_id, fd):
         try:
             readable, _, errors = select.select([fd], [], [fd], 0.05)
             if readable or errors:
-                output = os.read(fd, 4096)
+                output = os.read(fd, 65536)
                 if not output:
                     # EOF — process exited
                     break
@@ -956,6 +957,11 @@ def configure_pat():
 @app.route("/api/session", methods=["POST"])
 def create_session():
     """Create a new terminal session."""
+    # Quick reject before forking a PTY (approximate — authoritative check below)
+    with sessions_lock:
+        if len(sessions) >= MAX_CONCURRENT_SESSIONS:
+            return jsonify({"error": f"Maximum {MAX_CONCURRENT_SESSIONS} concurrent sessions reached. Close an existing session first."}), 429
+
     data = request.get_json(silent=True) or {}
     label = data.get("label", "")
     try:
@@ -997,6 +1003,15 @@ def create_session():
         session_id = str(uuid.uuid4())
 
         with sessions_lock:
+            # Authoritative check under the same lock as insertion — prevents
+            # TOCTOU race where two concurrent requests both pass the early check.
+            if len(sessions) >= MAX_CONCURRENT_SESSIONS:
+                os.close(master_fd)
+                try:
+                    os.kill(pid, signal.SIGKILL)
+                except OSError:
+                    pass
+                return jsonify({"error": f"Maximum {MAX_CONCURRENT_SESSIONS} concurrent sessions reached. Close an existing session first."}), 429
             sessions[session_id] = {
                 "master_fd": master_fd,
                 "pid": pid,

app.yaml

@@ -12,3 +12,5 @@ env:
     value: databricks-gpt-5-3-codex
   - name: CLAUDE_CODE_DISABLE_AUTO_MEMORY
     value: 0
+  - name: MAX_CONCURRENT_SESSIONS
+    value: "5"

docs/deployment.md

@@ -11,7 +11,7 @@ The simplest way — no CLI, no cloning, everything stays in the Databricks UI.
 1. Go to **Databricks → Apps → Create App**
 2. Choose **Custom App** and connect this Git repo:
    ```
-   https://github.com/datasciencemonkey/coding-agents-in-databricks.git
+   https://github.com/datasciencemonkey/coding-agents-databricks-apps.git
    ```
 3. Click **Deploy**
 4. Open the app — on first terminal session, paste a short-lived PAT when prompted
@@ -30,8 +30,8 @@ If you prefer working from the terminal or need more control:
 
 ```bash
 databricks repos create \
-  --url https://github.com/datasciencemonkey/coding-agents-in-databricks.git \
-  --path /Workspace/Users/<your-email>/apps/coding-agents-in-databricks
+  --url https://github.com/datasciencemonkey/coding-agents-databricks-apps.git \
+  --path /Workspace/Users/<your-email>/apps/coding-agents-databricks-apps
 ```
 
 ### 2. Configure `app.yaml`
@@ -56,7 +56,7 @@ No secrets or resources to configure. On first terminal session, paste a short-l
 
 ```bash
 databricks apps deploy <your-app-name> \
-  --source-code-path /Workspace/Users/<your-email>/apps/coding-agents-in-databricks
+  --source-code-path /Workspace/Users/<your-email>/apps/coding-agents-databricks-apps
 ```
 
 > **Tip:** To update later, just `git pull` in the workspace repo and re-deploy.

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "coda"
-version = "0.16.7"
+version = "0.17.0"
 description = "CoDA - Coding Agents on Databricks Apps"
 requires-python = ">=3.10"
 dependencies = [
@@ -9,8 +9,7 @@ dependencies = [
     "simple-websocket>=1.0",
     "claude-agent-sdk",
     "databricks-sdk>=0.20.0",
-    "mlflow-tracing>=3.4",
-    "opentelemetry-exporter-otlp-proto-grpc",
+    "mlflow-skinny==3.10.1",
     "requests",
     "cryptography>=46.0.6",
 ]

requirements.txt

@@ -1,5 +1,7 @@
 # This file was autogenerated by uv via the following command:
 #    uv pip compile pyproject.toml -o requirements.txt
+annotated-doc==0.0.4
+    # via fastapi
 annotated-types==0.7.0
     # via pydantic
 anyio==4.13.0
@@ -20,7 +22,7 @@ blinker==1.9.0
     #   flask
     #   flask-socketio
 cachetools==7.0.5
-    # via mlflow-tracing
+    # via mlflow-skinny
 certifi==2026.2.25
     # via
     #   httpcore
@@ -36,7 +38,10 @@ click==8.3.1
     # via
     #   flask
     #   flask-socketio
+    #   mlflow-skinny
     #   uvicorn
+cloudpickle==3.1.2
+    # via mlflow-skinny
 cryptography==46.0.6
     # via
     #   coda (pyproject.toml)
@@ -45,19 +50,21 @@ cryptography==46.0.6
 databricks-sdk==0.102.0
     # via
     #   coda (pyproject.toml)
-    #   mlflow-tracing
+    #   mlflow-skinny
+fastapi==0.135.3
+    # via mlflow-skinny
 flask==3.1.3
     # via
     #   coda (pyproject.toml)
     #   flask-socketio
 flask-socketio==5.6.1
     # via coda (pyproject.toml)
+gitdb==4.0.12
+    # via gitpython
+gitpython==3.1.46
+    # via mlflow-skinny
 google-auth==2.49.1
     # via databricks-sdk
-googleapis-common-protos==1.73.1
-    # via opentelemetry-exporter-otlp-proto-grpc
-grpcio==1.80.0
-    # via opentelemetry-exporter-otlp-proto-grpc
 h11==0.16.0
     # via
     #   httpcore
@@ -75,7 +82,9 @@ idna==3.11
     #   httpx
     #   requests
 importlib-metadata==8.7.1
-    # via opentelemetry-api
+    # via
+    #   mlflow-skinny
+    #   opentelemetry-api
 itsdangerous==2.2.0
     # via flask
 jinja2==3.1.6
@@ -93,36 +102,25 @@ markupsafe==3.0.3
     #   werkzeug
 mcp==1.26.0
     # via claude-agent-sdk
-mlflow-tracing==3.10.1
+mlflow-skinny==3.10.1
     # via coda (pyproject.toml)
 opentelemetry-api==1.40.0
     # via
-    #   mlflow-tracing
-    #   opentelemetry-exporter-otlp-proto-grpc
+    #   mlflow-skinny
     #   opentelemetry-sdk
     #   opentelemetry-semantic-conventions
-opentelemetry-exporter-otlp-proto-common==1.40.0
-    # via opentelemetry-exporter-otlp-proto-grpc
-opentelemetry-exporter-otlp-proto-grpc==1.40.0
-    # via coda (pyproject.toml)
 opentelemetry-proto==1.40.0
-    # via
-    #   mlflow-tracing
-    #   opentelemetry-exporter-otlp-proto-common
-    #   opentelemetry-exporter-otlp-proto-grpc
+    # via mlflow-skinny
 opentelemetry-sdk==1.40.0
-    # via
-    #   mlflow-tracing
-    #   opentelemetry-exporter-otlp-proto-grpc
+    # via mlflow-skinny
 opentelemetry-semantic-conventions==0.61b0
     # via opentelemetry-sdk
 packaging==26.0
-    # via mlflow-tracing
+    # via mlflow-skinny
 protobuf==6.33.6
     # via
     #   databricks-sdk
-    #   googleapis-common-protos
-    #   mlflow-tracing
+    #   mlflow-skinny
     #   opentelemetry-proto
 pyasn1==0.6.3
     # via pyasn1-modules
@@ -132,8 +130,9 @@ pycparser==3.0
     # via cffi
 pydantic==2.12.5
     # via
+    #   fastapi
     #   mcp
-    #   mlflow-tracing
+    #   mlflow-skinny
     #   pydantic-settings
 pydantic-core==2.41.5
     # via pydantic
@@ -142,13 +141,17 @@ pydantic-settings==2.13.1
 pyjwt==2.12.1
     # via mcp
 python-dotenv==1.2.2
-    # via pydantic-settings
+    # via
+    #   mlflow-skinny
+    #   pydantic-settings
 python-engineio==4.13.1
     # via python-socketio
 python-multipart==0.0.22
     # via mcp
 python-socketio==5.16.1
     # via flask-socketio
+pyyaml==6.0.3
+    # via mlflow-skinny
 referencing==0.37.0
     # via
     #   jsonschema
@@ -157,6 +160,7 @@ requests @ git+https://github.com/psf/requests@bc04dfd6dad4cb02cd92f5daa81eb562d
     # via
     #   coda (pyproject.toml)
     #   databricks-sdk
+    #   mlflow-skinny
 rpds-py==0.30.0
     # via
     #   jsonschema
@@ -165,19 +169,24 @@ simple-websocket==1.1.0
     # via
     #   coda (pyproject.toml)
     #   python-engineio
+smmap==5.0.3
+    # via gitdb
+sqlparse==0.5.5
+    # via mlflow-skinny
 sse-starlette==3.3.4
     # via mcp
 starlette==1.0.0
     # via
+    #   fastapi
     #   mcp
     #   sse-starlette
 typing-extensions==4.15.0
     # via
     #   anyio
-    #   grpcio
+    #   fastapi
     #   mcp
+    #   mlflow-skinny
     #   opentelemetry-api
-    #   opentelemetry-exporter-otlp-proto-grpc
     #   opentelemetry-sdk
     #   opentelemetry-semantic-conventions
     #   pydantic
@@ -187,13 +196,16 @@ typing-extensions==4.15.0
     #   typing-inspection
 typing-inspection==0.4.2
     # via
+    #   fastapi
     #   mcp
     #   pydantic
     #   pydantic-settings
 urllib3==2.6.3
     # via requests
 uvicorn==0.42.0
-    # via mcp
+    # via
+    #   mcp
+    #   mlflow-skinny
 werkzeug==3.1.7
     # via
     #   flask