# Process Runtime REST API

The **Process Runtime REST API** provides a set of RESTful services that allow external systems to **control, navigate, and interact with Process Flows** in ONEWEB.

These APIs enable client applications to:

* Start process instances
* Claim and complete user tasks
* Assign tasks to users or groups
* Retrieve tasks and process variables
* Manage runtime cache

All communication between external systems and the Process Runtime occurs over **HTTP/HTTPS**, making it suitable for system‑to‑system integration.

***

### Purpose of Process Runtime REST API

The Process Runtime REST APIs are designed to:

* Enable **external orchestration of business processes**
* Allow non‑ONEWEB applications to participate in workflows
* Support task‑based interactions (human tasks)
* Integrate BPM processes with external frontends or systems
* Provide runtime visibility into process execution

Typical use cases include:

* Custom task inbox applications
* Mobile or web clients interacting with workflow tasks
* External systems starting or completing business processes
* Automated orchestration across multiple systems

***

### Process Runtime REST API Endpoints

The table below lists the main REST API endpoints available for controlling and managing Process Flows at runtime.

| #  | Request Endpoint                                                                | Description                                     | HTTP Method |
| -- | ------------------------------------------------------------------------------- | ----------------------------------------------- | ----------- |
| 1  | `/BPMREST/service/runtime/process/start`                                        | Start a new process instance                    | **POST**    |
| 2  | `/BPMREST/service/runtime/process/[Process Name]/start`                         | Legacy API to start a process (not recommended) | **POST**    |
| 3  | `/BPMREST/service/runtime/tasks/[Task ID]/claim?user=[User Name]`               | Claim a task for a specific user                | **POST**    |
| 4  | `/BPMREST/service/runtime/tasks/[Task ID]/complete?user=[User Name]`            | Complete a task on behalf of a user             | **POST**    |
| 5  | `/BPMREST/service/runtime/instance/[Instance ID]/tasks`                         | Retrieve tasks for a given process instance     | **GET**     |
| 6  | `/BPMREST/service/runtime/tasks?[group/role/user]=[Name]`                       | Retrieve tasks by user, role, or group          | **GET**     |
| 7  | `/BPMREST/service/runtime/tasks/[Task ID]/variables`                            | Retrieve variables associated with a task       | **POST**    |
| 8  | `/BPMREST/service/runtime/tasks/[Task ID]/assign?user=[User1]&user=[User2]...`  | Assign a task to one or more users              | **POST**    |
| 9  | `/BPMREST/service/runtime/instance/[Instance ID]/tasks/assign?user=[User Name]` | Assign all tasks of an instance to a user       | **POST**    |
| 10 | `/BPMREST/service/runtime/refreshCache`                                         | Refresh cache for all process definitions       | **POST**    |
| 11 | `/BPMREST/service/runtime/classAction`                                          | Refresh cache for a specific process            | **POST**    |

***

### Common Integration Scenarios

Using Process Runtime REST APIs, external systems can:

* Trigger process execution from backend systems
* Build custom workflow UIs without using ONEWEB UI
* Synchronize human task execution with external applications
* Manage task ownership dynamically
* Monitor and coordinate long‑running business processes

***

### Notes on API Usage

* Endpoint parameters such as **Process Name**, **Task ID**, and **Instance ID** must match runtime values
* Authentication and authorization depend on Process Runtime security setup
* The **legacy start process API** is still available but should not be used in new implementations
* Cache refresh APIs should be used carefully in production environments

***

### Additional Documentation

For full API details, request/response formats, parameters, and examples, please refer to the official API guide:

> **Process Runtime API – Full Reference**\
> <https://docs.oneweb.tech/oneweb/api-guide/process-runtime-api/list-all-methods-of-rest-api-and-explain-the-api-functionality>

***

### Summary

The **Process Runtime REST API** enables external systems to directly interact with and control **business processes** running in ONEWEB.

With these APIs, developers can:

* Start and manage process instances
* Claim, assign, and complete human tasks
* Retrieve runtime tasks and variables
* Integrate BPM workflows with external systems

Process Runtime REST APIs are essential for building **workflow‑driven, system‑to‑system, and enterprise‑scale integrations** using ONEWEB.


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