BetaJSONSchemaOutputFormat doesn't support enum fields?

[bgeesaman]

Forgive me if this is pebac, but looking at the schema parsing logic in the SDK here:

anthropic-sdk-go/schemautil.go

Line 54 in 0e4a219

var supportedSchemaKeys = []string{

does not list enum as supported, but the docs appear to suggest they do/should: https://platform.claude.com/docs/en/build-with-claude/structured-outputs#json-schema-limitations

I was able to set them back with an inelegant workaround and it appears to work just fine (tested against anthropic API and Azure AI Anthropic API) with Haiku 4.5

...
			// SDK's BetaJSONSchemaOutputFormat strips "enum" fields
			// (Possible bug? enum is supported per docs but not in supportedSchemaKeys list)
			// Transform the schema with SDK's function, then restore enum fields
			transformed := anthropic.BetaJSONSchemaOutputFormat(a.outputFormatSchema)
			restoreEnumFields(transformed.Schema, a.outputFormatSchema)

			betaParams := anthropic.BetaMessageNewParams{
				Model:        a.model,
				MaxTokens:    a.maxTokens,
				Messages:     convertToBetaMessages(messages),
				Temperature:  param.Opt[float64]{Value: a.temperature},
				System:       []anthropic.BetaTextBlockParam{betaSystemPrompt},
				OutputFormat: transformed,
				Betas:        []anthropic.AnthropicBeta{"structured-outputs-2025-11-13"},
			}
...

As a separate test, I added "enum" to schemautil.go at line 75 (and removed this restoreEnumFields function) and it worked just fine.