> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ionworks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Convert Json To Expression

> Convert a JSON-serialized PyBaMM symbol back to an expression string.

This reconstructs a PyBaMM expression string from the JSON representation.
The resulting expression can be evaluated back to the same symbol.

Parameters
----------
request : JsonToExpressionRequest
    Request body containing the JSON-serialized PyBaMM symbol

Returns
-------
JsonToExpressionResponse
    Response with the expression string



## OpenAPI

````yaml https://api.ionworks.com/openapi.json post /variables/convert-json-to-expression
openapi: 3.1.0
info:
  title: FastAPI
  version: 0.1.0
servers:
  - url: https://api.ionworks.com
    description: Production
security: []
paths:
  /variables/convert-json-to-expression:
    post:
      tags:
        - variables
      summary: Convert Json To Expression
      description: >-
        Convert a JSON-serialized PyBaMM symbol back to an expression string.


        This reconstructs a PyBaMM expression string from the JSON
        representation.

        The resulting expression can be evaluated back to the same symbol.


        Parameters

        ----------

        request : JsonToExpressionRequest
            Request body containing the JSON-serialized PyBaMM symbol

        Returns

        -------

        JsonToExpressionResponse
            Response with the expression string
      operationId: convert_json_to_expression_variables_convert_json_to_expression_post
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/JsonToExpressionRequest'
        required: true
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/JsonToExpressionResponse'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    JsonToExpressionRequest:
      properties:
        value:
          additionalProperties: true
          type: object
          title: Value
      type: object
      required:
        - value
      title: JsonToExpressionRequest
      description: Request body for converting JSON-serialized PyBaMM symbol to string.
    JsonToExpressionResponse:
      properties:
        expression:
          type: string
          title: Expression
      type: object
      required:
        - expression
      title: JsonToExpressionResponse
      description: Response body with PyBaMM expression string.
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
              - type: string
              - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
        - loc
        - msg
        - type
      title: ValidationError

````