JSON: Get Value¶
Extracts a value from JSON data using a dot-separated key path. Works with dicts, lists, or JSON strings and supports numeric indices for arrays (e.g., items.0). If the path cannot be resolved, it returns a supplied default value.
Usage¶
Use this node when you need to read a specific field or nested value from JSON data within a workflow. Typical usage includes pulling a property from an API response, selecting a list item by index, or safely retrieving deeply nested values with a fallback default.
Inputs¶
| Field | Required | Type | Description | Example |
|---|---|---|---|---|
| json_data | True | WILDCARD | The JSON source to read from. Accepts a Python dict, list, or a JSON-formatted string. | {"user": {"name": "Ada", "id": 123}, "items": [{"title": "First"}]} |
| key_path | True | STRING | Dot-separated path to the target value. Use dots to traverse objects and numeric segments to index lists. | items.0.title |
| default_value | False | WILDCARD | Value to return if the path does not exist, resolves to None, or an error occurs. | Not found |
Outputs¶
| Field | Type | Description | Example |
|---|---|---|---|
| value | WILDCARD | The value found at the specified key path. If not found or an error occurs, returns the provided default_value. | First |
Important Notes¶
- Path format: Use dot-separated keys for objects and numeric segments for lists (e.g., "user.name", "items.0.title").
- Input parsing: If json_data is a string, the node attempts to parse it as JSON before traversal.
- Empty path behavior: If key_path is empty, the node returns the original json_data unchanged.
- Missing values: If a key is missing, an index is invalid, the traversal hits a non-container, or a step resolves to None, the node returns default_value.
- Error handling: On unexpected errors (including invalid JSON strings), the node returns default_value.
Troubleshooting¶
- Returned default instead of value: Verify the key_path spelling and structure matches the JSON. Ensure array indices are numeric and within range.
- Invalid JSON string: If json_data is a string, confirm it is valid JSON. Use a JSON validation tool or a dedicated validator node first.
- Type mismatch along path: If a segment expects a dict but encounters a list (or vice versa), adjust the path (e.g., add a numeric index for lists).
- Received entire input back: This happens when key_path is empty. Provide a non-empty path to extract a specific value.
- Unexpected None: If an intermediate value is None, the node returns default_value. Check your source data or provide a suitable fallback.