expect(params.max_output_tokens).toBe(65_536);

});

it("uses top-level instructions for Codex responses and strips unsupported ChatGPT params", () => {

it("uses top-level instructions for Codex responses and preserves prompt cache identity", () => {

const params = buildOpenAIResponsesParams(

{

id: "gpt-5.4",

expect(params.input?.some((item) => item.role === "system" || item.role === "developer")).toBe(

false,

);

expect(params).not.toHaveProperty("prompt_cache_key");

expect(params.prompt_cache_key).toBe("session-123");

expect(params.store).toBe(false);

expect(params).not.toHaveProperty("metadata");

expect(params).not.toHaveProperty("max_output_tokens");

expect(params).not.toHaveProperty("temperature");

});

it("sanitizes Codex responses params after payload hooks mutate them", () => {

it("sanitizes Codex responses params after payload hooks mutate them without stripping cache identity", () => {

const payload = {

model: "gpt-5.4",

input: [],

payload,

);

expect(sanitized).not.toHaveProperty("prompt_cache_key");

expect(sanitized.prompt_cache_key).toBe("session-123");

expect(sanitized).not.toHaveProperty("metadata");

expect(sanitized).not.toHaveProperty("max_output_tokens");

expect(sanitized).not.toHaveProperty("prompt_cache_retention");

id?: string;

call_id?: string;

phase?: string;

encrypted_content?: string;

}>;

};

expect(params.input?.some((item) => item.type === "reasoning")).toBe(false);

const reasoningItem = params.input?.find((item) => item.type === "reasoning");

expect(reasoningItem).toMatchObject({

type: "reasoning",

encrypted_content: "ciphertext",

});

expect(reasoningItem?.id).toBeUndefined();

const assistantMessage = params.input?.find(

(item) => item.type === "message" && item.role === "assistant",

);