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# ConfigLoader

> JSON configuration loading with environment variable substitution.

[securityconfig]: /docs/server-sdks/reference/python/agents/configuration/security-config

[mcp-gateway]: /docs/server-sdks/reference/python/agents/cli/mcp-gateway

[findconfigfile]: /docs/server-sdks/reference/python/agents/configuration/config-loader/find-config-file

[get]: /docs/server-sdks/reference/python/agents/configuration/config-loader/get

[getconfig]: /docs/server-sdks/reference/python/agents/configuration/config-loader/get-config

[getconfigfile]: /docs/server-sdks/reference/python/agents/configuration/config-loader/get-config-file

[getsection]: /docs/server-sdks/reference/python/agents/configuration/config-loader/get-section

[hasconfig]: /docs/server-sdks/reference/python/agents/configuration/config-loader/has-config

[mergewithenv]: /docs/server-sdks/reference/python/agents/configuration/config-loader/merge-with-env

[substitutevars]: /docs/server-sdks/reference/python/agents/configuration/config-loader/substitute-vars

`ConfigLoader` loads JSON configuration files and substitutes environment
variables using `${VAR|default}` syntax. It is used internally by
[`SecurityConfig`][securityconfig]
and the [`mcp-gateway`][mcp-gateway] service,
and can be used directly for custom configuration needs.

```python
from signalwire.core.config_loader import ConfigLoader
```

## **Properties**

**`config_paths`** `list[str]`

List of file paths checked during initialization. The first existing file is loaded.

---

## **Methods**

#### [find\_config\_file](/docs/server-sdks/reference/python/agents/configuration/config-loader/find-config-file)

Static method to locate a config file without loading it.

#### [get](/docs/server-sdks/reference/python/agents/configuration/config-loader/get)

Get a configuration value by dot-notation path.

#### [get\_config](/docs/server-sdks/reference/python/agents/configuration/config-loader/get-config)

Get the raw configuration dictionary before environment variable substitution.

#### [get\_config\_file](/docs/server-sdks/reference/python/agents/configuration/config-loader/get-config-file)

Get the path of the loaded config file.

#### [get\_section](/docs/server-sdks/reference/python/agents/configuration/config-loader/get-section)

Get an entire configuration section with environment variables substituted.

#### [has\_config](/docs/server-sdks/reference/python/agents/configuration/config-loader/has-config)

Check whether a configuration file was successfully loaded.

#### [merge\_with\_env](/docs/server-sdks/reference/python/agents/configuration/config-loader/merge-with-env)

Merge configuration with environment variables matching a prefix.

#### [substitute\_vars](/docs/server-sdks/reference/python/agents/configuration/config-loader/substitute-vars)

Recursively substitute environment variables in configuration values.

## **Example**

```python {4,8}
from signalwire.core.config_loader import ConfigLoader

# Auto-discover config file
loader = ConfigLoader()
print(f"Config loaded: {loader.has_config()}")

# Explicit config file path
loader = ConfigLoader(["./my-config.json", "/etc/myapp/config.json"])
print(f"Config file: {loader.get_config_file()}")
```

> JSON configuration loading with environment variable substitution.

## Docs

- [find_config_file](https://signalwire.com/docs/server-sdks/reference/python/agents/configuration/config-loader/find-config-file.md): Static method to locate a config file without loading it.
- [get](https://signalwire.com/docs/server-sdks/reference/python/agents/configuration/config-loader/get.md): Get a configuration value by dot-notation path.
- [get_config](https://signalwire.com/docs/server-sdks/reference/python/agents/configuration/config-loader/get-config.md): Get the raw configuration dictionary before environment variable substitution.
- [get_config_file](https://signalwire.com/docs/server-sdks/reference/python/agents/configuration/config-loader/get-config-file.md): Get the path of the loaded config file.
- [get_section](https://signalwire.com/docs/server-sdks/reference/python/agents/configuration/config-loader/get-section.md): Get an entire configuration section with environment variables substituted.
- [has_config](https://signalwire.com/docs/server-sdks/reference/python/agents/configuration/config-loader/has-config.md): Check whether a configuration file was successfully loaded.
- [merge_with_env](https://signalwire.com/docs/server-sdks/reference/python/agents/configuration/config-loader/merge-with-env.md): Merge configuration with environment variables matching a prefix.
- [substitute_vars](https://signalwire.com/docs/server-sdks/reference/python/agents/configuration/config-loader/substitute-vars.md): Recursively substitute environment variables in configuration values.