Limit MCP version

Dockerfile

@@ -52,7 +52,7 @@ RUN pip install --no-cache-dir --find-links=/wheels \
     node-wire-fhir-cerner \
     node-wire-fhir-epic \
     node-wire-salesforce \
-    "mcp>=1.6.0" \
+    "mcp>=1.6.0,<2" \
     && rm -rf /wheels
 
 RUN groupadd --system --gid 1000 app \

docker/fhir-cerner/Dockerfile

@@ -23,7 +23,7 @@ ENV PYTHONPATH=/app/src \
     NW_ALLOWED_CONNECTORS=fhir_cerner
 
 RUN pip install --no-cache-dir --find-links=/wheels \
-    node-wire-runtime node-wire-fhir-cerner "mcp>=1.6.0" \
+    node-wire-runtime node-wire-fhir-cerner "mcp>=1.6.0,<2" \
     && rm -rf /wheels
 
 RUN groupadd --system --gid 1000 app \

docker/fhir-epic/Dockerfile

@@ -23,7 +23,7 @@ ENV PYTHONPATH=/app/src \
     NW_ALLOWED_CONNECTORS=fhir_epic
 
 RUN pip install --no-cache-dir --find-links=/wheels \
-    node-wire-runtime node-wire-fhir-epic "mcp>=1.6.0" \
+    node-wire-runtime node-wire-fhir-epic "mcp>=1.6.0,<2" \
     && rm -rf /wheels
 
 RUN groupadd --system --gid 1000 app \

docker/google-drive/Dockerfile

@@ -23,7 +23,7 @@ ENV PYTHONPATH=/app/src \
     NW_ALLOWED_CONNECTORS=google_drive
 
 RUN pip install --no-cache-dir --find-links=/wheels \
-    node-wire-runtime node-wire-google-drive "mcp>=1.6.0" \
+    node-wire-runtime node-wire-google-drive "mcp>=1.6.0,<2" \
     && rm -rf /wheels
 
 RUN groupadd --system --gid 1000 app \

docker/salesforce/Dockerfile

@@ -24,7 +24,7 @@ ENV PYTHONPATH=/app/src \
     NW_ALLOWED_CONNECTORS=salesforce
 
 RUN pip install --no-cache-dir --find-links=/wheels \
-    node-wire-runtime node-wire-salesforce "mcp>=1.6.0" httpx \
+    node-wire-runtime node-wire-salesforce "mcp>=1.6.0,<2" httpx \
     && rm -rf /wheels
 
 RUN groupadd --system --gid 1000 app \

docker/slack/Dockerfile

@@ -23,7 +23,7 @@ ENV PYTHONPATH=/app/src \
     NW_ALLOWED_CONNECTORS=slack
 
 RUN pip install --no-cache-dir --find-links=/wheels \
-    node-wire-runtime node-wire-slack "mcp>=1.6.0" \
+    node-wire-runtime node-wire-slack "mcp>=1.6.0,<2" \
     && rm -rf /wheels
 
 RUN groupadd --system --gid 1000 app \

docker/smtp/Dockerfile

@@ -23,7 +23,7 @@ ENV PYTHONPATH=/app/src \
     NW_ALLOWED_CONNECTORS=smtp
 
 RUN pip install --no-cache-dir --find-links=/wheels \
-    node-wire-runtime node-wire-smtp "mcp>=1.6.0" \
+    node-wire-runtime node-wire-smtp "mcp>=1.6.0,<2" \
     && rm -rf /wheels
 
 RUN groupadd --system --gid 1000 app \

docker/stripe/Dockerfile

@@ -23,7 +23,7 @@ ENV PYTHONPATH=/app/src \
     NW_ALLOWED_CONNECTORS=stripe
 
 RUN pip install --no-cache-dir --find-links=/wheels \
-    node-wire-runtime node-wire-stripe "mcp>=1.6.0" \
+    node-wire-runtime node-wire-stripe "mcp>=1.6.0,<2" \
     && rm -rf /wheels
 
 RUN groupadd --system --gid 1000 app \

nw-mcp-builder/src/nw_mcp_builder/generate/connector_project.py

@@ -217,7 +217,7 @@ def _pyproject_toml(
 dependencies = [
     "node-wire-runtime",
     "{connector_pkg}",
-    "mcp>=1.6.0",
+    "mcp>=1.6.0,<2",
     "httpx[http2]>=0.27.0,<0.28.0",
     "python-dotenv>=1.0.0",
 ]
@@ -401,7 +401,7 @@ def _dockerfile(
     NW_CONFIG_PATH=/app/config/connectors.yaml
 
 RUN pip install --no-cache-dir --find-links=/wheels \\
-    node-wire-runtime {connector_pkg} "mcp>=1.6.0" "httpx[http2]>=0.27.0,<0.28.0" \\
+    node-wire-runtime {connector_pkg} "mcp>=1.6.0,<2" "httpx[http2]>=0.27.0,<0.28.0" \\
     && pip install --no-cache-dir -e /app \\
     && rm -rf /wheels
 

pyproject.toml

@@ -68,7 +68,7 @@ nw-slack = "agents.slack_mcp:main"
 
 [project.optional-dependencies]
 agents = [
-  "mcp>=1.6.0",                    # Official Python MCP SDK (includes FastMCP)
+  "mcp>=1.6.0,<2",                 # Official Python MCP SDK (includes FastMCP); v2 breaks low-level decorators
   "groq>=0.9.0",                   # Groq LLM SDK
   "openai>=1.30.0",                # OpenAI SDK
   "google-generativeai>=0.7.0",    # Gemini SDK