> For the complete documentation index, see [llms.txt](https://help.tillit.cloud/tillit/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.tillit.cloud/tillit/knowledge-base/setting-up-tillit/integrations/wire-flow/introduction-and-concepts.md).

# Introduction & Concepts

Wire Flow is a **middleware tool** that lets integration engineers build data transformation and orchestration pipelines visually — connecting systems, parsing file formats, calling APIs, and routing data, all without managing servers or writing code.

**Common use cases:**

* Parse incoming CSV or Excel files and send the data to an external API
* Receive an MQTT message from a device and trigger a downstream workflow
* Transform XML orders to JSON, validate them, and route them conditionally
* Invoke an AI model to classify incoming data, then send an email based on the result

## Core Concepts

| Term         | What it means                                                                                   |
| ------------ | ----------------------------------------------------------------------------------------------- |
| **BPMN**     | A standard diagram notation for workflows. Nodes = tasks, arrows = flow between them            |
| **Workflow** | A sequence of connected tasks that runs automatically when triggered                            |
| **Tenant**   | Your isolated environment. All workflows, credentials, and executions are scoped to your tenant |

## EXPRESS vs STANDARD Workflows

When creating a workflow, choose a type based on how long it runs and how it returns results.

|                       | EXPRESS                                            | STANDARD                                               |
| --------------------- | -------------------------------------------------- | ------------------------------------------------------ |
| **Max duration**      | 5 minutes                                          | Up to 1 year                                           |
| **Execution**         | Synchronous — waits and returns output immediately | Asynchronous — starts and completes in the background  |
| **Execution history** | Available via the Executions view                  | Full history available                                 |
| **Pricing**           | Per execution + duration                           | Per step transition                                    |
| **Best for**          | API transforms, short ETL, file processing         | Long-running processes, human approvals, waiting tasks |

{% hint style="info" %}
Most integration workflows should use **EXPRESS**. If a single message is taking longer than 5 minutes, that is a signal something is wrong upstream.
{% endhint %}

**A note on EXPRESS reliability:** In rare failure scenarios, AWS may re-invoke an EXPRESS workflow. Design your workflows to be safe to run twice — for example, use update-or-create operations rather than blind inserts when writing to external systems.