LoopfourDevelopers
Use the Loopfour API, webhooks and MCP to create and run workflows from your own systems, with reference pages for each block and integration.
This section is for engineers and technical operators who work with Loopfour from code. If you build and review workflows in Studio, start with the Guides instead.
From your own systems you can:
- Create and change workflows as JSON through the REST API, and validate them before you save.
- Start runs from your code, on a schedule, from an inbound email, or when a connected app such as HubSpot, Airwallex or Slack reports an event.
- Follow runs: read their status, output and step results, and retry, restart or cancel them.
- Receive run events on your own endpoint through outbound webhooks.
- Work from an AI coding tool such as Claude Code or Codex over MCP.
The REST API lives at https://workflow.loopfour.ai/api/v1 and takes an API key in the x-api-key header.
Get started
Quickstart
Create a workflow, activate it and start your first run with the API.
Authentication
Create an API key, choose scopes and handle rate limits.
Workflow format
The JSON structure of a workflow: trigger, steps and settings.
Variable references
Pass data between steps with references like steps.id.field in double braces.
Error handling
Step failure strategies, retries and the API error format.
Triggers
Triggers overview
The ways a run can start, and where its data lands.
API trigger
Start a run from your own code.
Webhook trigger
Start a run from an inbound HTTP event.
Schedule trigger
Run on a cron expression or a fixed interval.
Email trigger
Run when an email reaches the workflow's inbound address.
App event triggers
Run on HubSpot and Airwallex events.
Slack triggers
Run on Slack events, slash commands and button clicks.
Reference
Blocks
Configuration and output for each step type.
Integrations
Actions, inputs and outputs for each connected app.
API reference
Endpoints for workflows, runs, connections, tables and more.
MCP
Connect Claude Code or Codex to Loopfour.
Machine-readable docs
| Resource | What it is |
|---|---|
/openapi.json | The OpenAPI 3.1 spec as JSON |
/api/openapi.yaml | The same spec as YAML |
/llms.txt | An index of these docs for AI agents |
/llms-full.txt | The full text of these docs in one file |