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<@ULVA73B9P> I use from prefect.blocks.system import JSON in Prefect 2, how can I use this in Prefect 3?

:white_check_mark: thought for 133.6 seconds

Short answer: In Prefect 3, `prefect.blocks.system.JSON` was removed. Use Variables for non-sensitive JSON config, and use the Secret block for sensitive JSON.

- Variables (recommended for non-sensitive JSON)
  - Store
    ```
    from prefect.variables import Variable

    Variable.set("app_config", {"api_url": "https://...", "retries": 3}, overwrite=True)
    ```
  - Load
    ```
    from prefect.variables import Variable

    config = Variable.get("app_config")  # returns the dict directly
    ```
  - Docs: <https://docs.prefect.io/v3/concepts/variables/|Variables concept> • <https://docs.prefect.io/v3/api-ref/python/prefect-variables/|Variables API>

- Secret block (use for sensitive JSON, e.g., credentials)
  - Store
    ```
    from prefect.blocks.system import Secret

    Secret(value={"api_key": "sk-...", "region": "us-west-2"}).save("api_credentials", overwrite=True)
    ```
  - Load
    ```
    from prefect.blocks.system import Secret

    creds = Secret.load("api_credentials").get()  # returns a dict
    ```
  - Docs: <https://docs.prefect.io/v3/api-ref/python/prefect-blocks-system/#prefect.blocks.system.Secret|Secret block API> • <https://docs.prefect.io/v3/concepts/blocks/|Blocks concept>

Quick migration example
- Prefect 2 (before)
  ```
  from prefect.blocks.system import JSON

  cfg = JSON.load("app_config").value
  ```
- Prefect 3 (after, non-sensitive)
  ```
  from prefect.variables import Variable

  cfg = Variable.get("app_config")
  ```

Notes
- Variables are not encrypted and have a size limit (~5,000 chars). Use Secret for sensitive JSON, or consider a custom Block if you need structure/methods.