# JSON Path Mapping
Starting from **ONEWEB version 4.0.19.12**, Microflow Designer supports **JSONPath syntax** for extracting values from REST service responses that contain **complex or deeply nested JSON structures**.\
This capability enhances REST integration by allowing precise data extraction during **output parameter mapping**, without requiring additional transformation or custom logic.
JSON Path Mapping is especially useful when integrating with third‑party APIs that return large or highly structured JSON payloads.
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### Purpose of JSON Path Mapping
JSON Path Mapping is used to:
* Retrieve specific values from complex JSON responses
* Extract deeply nested fields or elements within JSON arrays
* Accurately map REST service responses to Business Objects
* Simplify REST integration without using custom code or Java Nodes
By enabling direct value extraction at the mapping level, JSON Path Mapping improves accuracy and reduces integration complexity.
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### Where JSON Path Is Applied in ONEWEB
JSONPath expressions are applied in the **Output Mapping screen** of a **REST Web Service Task**, specifically under the **RestDummyObject**.
In REST output mapping:
* Each output parameter can be associated with a **JSONPath expression**
* The expression defines **how and where** the value is extracted from the response JSON
* Extracted values are then mapped directly to Microflow or Business Object parameters
This keeps extraction logic **close to data flow**, improving traceability and maintainability.
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### Using JSON Path in REST Output Mapping
To apply JSONPath mapping in Microflow Designer:
* Configure a **REST Web Service Task** within a Microflow
* Open **Open Mapping Parameter** for the REST task
* Navigate to the **Output Mapping** section
* Under **RestDummyObject**, define the JSONPath expression for the required output parameter
JSONPath expressions are evaluated at runtime and used to extract values from the REST response.
*(Screenshots illustrating JSONPath configuration and mapping can be inserted here in the documentation.)*
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### JSONPath Reference
JSONPath uses an expression syntax similar to XPath but is designed specifically for JSON data structures.\
For detailed syntax rules and examples, refer to the official JSONPath documentation:
> Link:
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### Validating JSONPath with Online Tools
To simplify and validate mapping logic before applying it in ONEWEB, developers can use online JSONPath evaluators.
Commonly used tools include:
Link:
These tools allow developers to:
* Paste a sample REST JSON response
* Test multiple JSONPath expressions
* Identify the correct expression to extract the desired value
Validating JSONPath expressions externally helps reduce trial‑and‑error during Microflow configuration.
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### Best Practices for JSON Path Mapping
To ensure reliable and maintainable REST integrations:
* Always test JSONPath expressions using realistic sample responses
* Keep expressions as **specific as possible** to avoid ambiguous matches
* Pay close attention when extracting values from arrays
* Handle optional or missing fields gracefully
* Avoid overly complex expressions when simpler response structures are available
Following these practices improves integration robustness and minimizes runtime mapping errors.
***
### Summary
**JSON Path Mapping** enhances REST service integration in ONEWEB by enabling precise extraction of values from complex JSON responses.
With JSONPath support, Microflow Designer allows developers to:
* Map deeply nested REST response fields
* Improve accuracy of REST output mapping
* Simplify integrations without additional transformation logic
* Maintain clean and readable Microflow designs
This capability is especially important for **enterprise‑grade API integrations**, where response structures are often large, complex, and deeply nested.
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