Changelog

4.55.0

(feat): Add support for server URL templating with OpenAPI server variables. This enables dynamic base URL construction at runtime based on user-provided configuration.

OpenAPI definition example:

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servers:
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  - url: https://api.{region}.{environment}.example.com/v1
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    variables:
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      region:
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        default: us-east-1
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        enum: [us-east-1, us-west-2, eu-west-1]
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      environment:
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        default: prod
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        enum: [prod, staging, dev]

Generated constructor parameters: Server variables are exposed as optional constructor parameters with their default values:

• region: typing.Optional[str] - defaults to "us-east-1"
• server_url_environment: typing.Optional[str] - defaults to "prod" (prefixed to avoid shadowing)

Runtime URL interpolation: When server variables are provided, the SDK performs runtime URL template interpolation:

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from seed import SeedApi
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# Uses default: https://api.us-east-1.prod.example.com/v1
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client = SeedApi()
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# Custom region: https://api.eu-west-1.prod.example.com/v1
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client = SeedApi(region="eu-west-1")
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# Custom region and environment: https://api.us-west-2.staging.example.com/v1
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client = SeedApi(region="us-west-2", server_url_environment="staging")

Multiple base URL environments: For APIs with multiple base URLs (e.g., separate base and auth URLs), each URL template is interpolated independently with the same server variables.

x-fern-default-url extension: When present in the OpenAPI spec, this extension specifies which server URL should be used as the default environment, overriding the first server in the list.

4.54.4

(fix): The use_provided_defaults config option no longer applies defaults to inlined request body properties.