Spring AI Add ability to configure custom HTTP headers at ChatClient.Builder

Currently, Spring AI only provides a straightforward way to set custom HTTP headers in certain provider-specific integrations (e.g., spring.ai.azure.openai.custom-headers for Azure OpenAI). For other providers accessed via the ChatClient API — especially those using OpenAI-compatible endpoints like Google Gemini — there is no native mechanism to set provider-specific HTTP headers during client creation.

Expected Behavior Enable adding custom HTTP headers directly when building a ChatClient. For example:

ChatClient client = ChatClient.builder() .baseUrl("https://generativelanguage.googleapis.com/v1beta/openai/") .apiKey("...") .customHeader("X-Server-Throughput-Key", "my-throughput-token") .customHeader("Another-Header", "value") .build();

Benefits:

Simplifies integrating with providers that require extra headers (e.g., Gemini throughput provisioning keys, experimental API )

Context

I work for enterprise system. We have reserved provisioning throughput on vertex ai Gemini. But can't use it natively with Spring AI

Comment From: alanta335

have you tried using options

For example:

chatClient
                    .prompt()
                    .options(OpenAiChatOptions.builder()
                            .httpHeaders(Map.of("X-Server-Throughput-Key", "my-throughput-token"))
                            .build())