Node Handlers

Table of contents

  1. Status Legend
  2. Triggers
  3. HTTP
  4. Flow Control
  5. Data Transform
  6. Databases
  7. Apps & SaaS
  8. AI & LangChain
  9. Fallback Handler
  10. Requesting a New Handler

Status Legend

Status Meaning
✅ Full Concrete Python generated — no manual editing required for standard use
⚠️ Partial Code generated, but some paths include # TODO comments for edge cases
🔧 Stub Scaffold with explicit TODO — requires manual completion

Triggers

Trigger nodes control the output mode of the entire generated file.

Node type Status Output
n8n-nodes-base.manualTrigger ⚠️ Partial def run_workflow(): + if __name__ == "__main__"
n8n-nodes-base.scheduleTrigger ⚠️ Partial Same as manual trigger with schedule metadata comments
n8n-nodes-base.webhook ✅ Full @app.post("/path") FastAPI route with Pydantic request model
@n8n/n8n-nodes-langchain.chatTrigger ✅ Full @app.post("/chat") FastAPI route with message extraction

Note: Multiple trigger aliases (manualTrigger / manualtrigger, etc.) are registered identically.

HTTP

Node type Status Generated construct
n8n-nodes-base.httpRequest ✅ Full requests.request(method, url, headers=..., params=..., json=..., auth=...)

Features:

  • All HTTP methods (GET, POST, PUT, PATCH, DELETE)
  • Query parameters and custom headers
  • JSON and form body support
  • Bearer token / Basic auth with os.getenv() credential placeholders
  • Response body parsed as JSON with text fallback

Flow Control

Node type Status Generated construct
n8n-nodes-base.if ✅ Full if condition: ... else: ... with branch item lists
n8n-nodes-base.switch 🔧 Stub Multi-branch scaffold with TODO
n8n-nodes-base.merge 🔧 Stub TODO pass-through
n8n-nodes-base.splitInBatches 🔧 Stub TODO scaffold

The IF handler integrates with the expression engine to translate n8n conditions into Python boolean expressions, and uses post-dominator analysis to correctly scope the merge point after branches.

Data Transform

Node type Status Generated construct
n8n-nodes-base.set ✅ Full Builds {"json": {...}} items from field assignments; supports raw mode
n8n-nodes-base.filter ⚠️ Partial List comprehension with translated condition expression
n8n-nodes-base.itemLists 🔧 Stub TODO scaffold
n8n-nodes-base.code ⚠️ Partial Python code blocks passed through; JS blocks commented with TODO

Databases

All database handlers are currently stubs that scaffold the operation and credential environment variables. They are valid Python — they just need the implementation filled in.

Node type Generated packages
n8n-nodes-base.postgres psycopg2-binary
n8n-nodes-base.mySql pymysql
n8n-nodes-base.mongoDb pymongo

Apps & SaaS

All app handlers are currently stubs.

Node type Generated packages
n8n-nodes-base.slack slack-sdk
n8n-nodes-base.notion notion-client
n8n-nodes-base.airtable pyairtable
n8n-nodes-base.googleSheets google-api-python-client, google-auth-httplib2, google-auth-oauthlib

AI & LangChain

Node type Status Generated construct
@n8n/n8n-nodes-langchain.openAi 🔧 Stub TODO with model/operation metadata
@n8n/n8n-nodes-langchain.lmChatOpenAi ⚠️ Partial ChatOpenAI(model=..., temperature=...) instantiation
@n8n/n8n-nodes-langchain.agent ⚠️ Partial LangChain AgentExecutor scaffold with composed tools and memory
@n8n/n8n-nodes-langchain.memoryBufferWindow ⚠️ Partial ConversationBufferWindowMemory — requires langchain-classic
Other @n8n/n8n-nodes-langchain.* 🔧 Stub Generic LangChain TODO scaffold

LangChain packages: When any ConversationBuffer*Memory node is detected, both langchain and langchain-classic are added to requirements.txt.

Fallback Handler

Any unrecognised node type is handled by the fallback handler, which emits:

# TODO: Unsupported node type 'n8n-nodes-base.xyzNode'
# Node: "My Node Name"
n_my_node_name_output = previous_output  # pass-through

This keeps the generated workflow runnable while clearly marking the gap. Contributions to implement these nodes are welcome — see Contributing.

Requesting a New Handler

Open a Node Handler Request on GitHub.