# Set the OpenAPI `basePath` property
<a name="api-gateway-import-api-basePath"></a>

In [OpenAPI 2.0](https://github.com/OAI/OpenAPI-Specification/blob/main/versions/2.0.md), you can use the `basePath` property to provide one or more path parts that precede each path defined in the `paths` property. Because API Gateway has several ways to express a resource's path, the Import API feature provides the following options for interpreting the `basePath` property during import: ignore, prepend, and split.

In [https://swagger.io/docs/specification/api-host-and-base-path/](https://swagger.io/docs/specification/api-host-and-base-path/), `basePath` is no longer a top-level property. Instead, API Gateway uses a [server variable](https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.0.md#serverVariableObject) as a convention. The Import API feature provides the same options for interpreting the base path during import. The base path is identified as follows:
+ If the API doesn't contain any `basePath` variables, the Import API feature checks the `server.url` string to see if it contains a path beyond `"/"`. If it does, that path is used as the base path.
+ If the API contains only one `basePath` variable, the Import API feature uses it as the base path, even if it's not referenced in the `server.url`.
+ If the API contains multiple `basePath` variables, the Import API feature uses only the first one as the base path.

## Ignore
<a name="api-gateway-import-api-basePath-ignore"></a>

If the OpenAPI file has a `basePath` value of `/a/b/c` and the `paths` property contains `/e` and `/f`, the following `POST` or `PUT` request: 

```
POST /restapis?mode=import&basepath=ignore
```



```
PUT /restapis/api_id?basepath=ignore
```

 results in the following resources in the API: 
+ `/`
+ `/e`
+ `/f`

 The effect is to treat the `basePath` as if it was not present, and all of the declared API resources are served relative to the host. This can be used, for example, when you have a custom domain name with an API mapping that doesn't include a *Base Path* and a *Stage* value that refers to your production stage. 

**Note**  
 API Gateway automatically creates a root resource for you, even if it isn't explicitly declared in your definition file. 

 When unspecified, `basePath` takes `ignore` by default. 

## Prepend
<a name="api-gateway-import-api-basePath-prepend"></a>

 If the OpenAPI file has a `basePath` value of `/a/b/c` and the `paths` property contains `/e` and `/f`, the following `POST` or `PUT` request: 

```
POST /restapis?mode=import&basepath=prepend
```



```
PUT /restapis/api_id?basepath=prepend
```

 results in the following resources in the API: 
+ `/`
+ `/a`
+ `/a/b`
+ `/a/b/c`
+ `/a/b/c/e`
+ `/a/b/c/f`

 The effect is to treat the `basePath` as specifying additional resources (without methods) and to add them to the declared resource set. This can be used, for example, when different teams are responsible for different parts of an API and the `basePath` could reference the path location for each team's API part. 

**Note**  
 API Gateway automatically creates intermediate resources for you, even if they aren't explicitly declared in your definition. 

## Split
<a name="api-gateway-import-api-basePath-split"></a>

 If the OpenAPI file has a `basePath` value of `/a/b/c` and the `paths` property contains `/e` and `/f`, the following `POST` or `PUT` request: 

```
POST /restapis?mode=import&basepath=split
```



```
PUT /restapis/api_id?basepath=split
```

 results in the following resources in the API: 
+ `/`
+ `/b`
+ `/b/c`
+ `/b/c/e`
+ `/b/c/f`

 The effect is to treat top-most path part, `/a`, as the beginning of each resource's path, and to create additional (no method) resources within the API itself. This could, for example, be used when `a` is a stage name that you want to expose as part of your API.