fix(protocols): condition input content on its message role

packages/gateway/src/data-plane/chat/openai-responses/items/normalize-assistant-content.ts

@@ -12,9 +12,9 @@
 // content type. Only `role: 'assistant'` is rewritten; user/system/developer
 // messages keep `input_text` because that IS the correct type on those roles.
 
-import type { OpenAIResponsesInputContent, CanonicalOpenAIResponsesInputItem } from '@floway-dev/protocols/openai-responses';
+import type { OpenAIResponsesAssistantInputContent, CanonicalOpenAIResponsesInputItem } from '@floway-dev/protocols/openai-responses';
 
-const normalizeAssistantContentBlocks = (content: string | OpenAIResponsesInputContent[]): string | OpenAIResponsesInputContent[] => {
+const normalizeAssistantContentBlocks = (content: string | OpenAIResponsesAssistantInputContent[]): string | OpenAIResponsesAssistantInputContent[] => {
   if (typeof content === 'string') return content;
   let mutated = false;
   const next = content.map(block => {
@@ -28,7 +28,7 @@ const normalizeAssistantContentBlocks = (content: string | OpenAIResponsesInputC
 const normalizeItem = (item: CanonicalOpenAIResponsesInputItem): CanonicalOpenAIResponsesInputItem => {
   if (item.type !== 'message' || item.role !== 'assistant') return item;
   const next = normalizeAssistantContentBlocks(item.content);
-  return next === item.content ? item : { ...item, content: next };
+  return next === item.content ? item : { ...item, content: next } as CanonicalOpenAIResponsesInputItem;
 };
 
 export const normalizeAssistantInputText = (input: CanonicalOpenAIResponsesInputItem[]): CanonicalOpenAIResponsesInputItem[] => {

packages/protocols/src/openai-chat-completions/index.ts

@@ -102,7 +102,6 @@ export interface OpenAIChatCompletionsFilePart { type: 'file'; file: { file_data
 export interface OpenAIChatCompletionsRefusalPart { type: 'refusal'; refusal: string }
 export type OpenAIChatCompletionsUserContentPart = OpenAIChatCompletionsTextPart | OpenAIChatCompletionsImagePart | OpenAIChatCompletionsInputAudioPart | OpenAIChatCompletionsFilePart;
 export type OpenAIChatCompletionsAssistantContentPart = OpenAIChatCompletionsTextPart | OpenAIChatCompletionsRefusalPart;
-export type OpenAIChatCompletionsContentPart = OpenAIChatCompletionsUserContentPart | OpenAIChatCompletionsRefusalPart;
 
 // Provider extension types belong only at the assistant boundary.
 export interface OpenAIChatCompletionsAssistantExtensions {

packages/protocols/src/openai-responses/index.ts

@@ -140,18 +140,21 @@ export type CanonicalOpenAIResponsesInputItem =
 
 export type OpenAIResponsesMessagePhase = 'commentary' | 'final_answer' | (string & {}) | null;
 
-export interface OpenAIResponsesInputMessageEx {
+interface OpenAIResponsesInputMessageFields {
   type: 'message';
   id?: string;
   status?: string;
-  role: 'user' | 'assistant' | 'system' | 'developer';
-  content: string | OpenAIResponsesInputContent[];
   phase?: OpenAIResponsesMessagePhase;
   // Codex marks base-instruction fragments on ordinary developer messages.
   // https://github.com/openai/codex/blob/0462dcc062b822bb8fff16cc31ce6eeab69823b9/codex-rs/core/tests/suite/responses_lite.rs#L136-L155
   internal_chat_message_metadata_passthrough?: Record<string, unknown>;
 }
 
+export type OpenAIResponsesInputMessageEx = OpenAIResponsesInputMessageFields & (
+  | { role: 'user' | 'system' | 'developer'; content: string | OpenAIResponsesInputContent[] }
+  | { role: 'assistant'; content: string | OpenAIResponsesAssistantInputContent[] }
+);
+
 // The OpenAI Responses request schema's EasyInputMessage makes the constant
 // `type: "message"` discriminator optional. Wire-facing payloads accept that
 // shorthand; gateway and translator boundaries normalize it before internal
@@ -178,7 +181,9 @@ export type CanonicalOpenAIResponsesPayload = Omit<OpenAIResponsesPayloadEx, 'in
   input: CanonicalOpenAIResponsesInputItem[];
 };
 
-export type OpenAIResponsesInputContent = CanonicalOpenAIResponsesText | OpenAIResponsesInputImage | OpenAIResponsesInputFile | OpenAIResponsesOutputRefusal;
+export type OpenAIResponsesInputContent = CanonicalOpenAIResponsesText | OpenAIResponsesInputImage | OpenAIResponsesInputFile;
+
+export type OpenAIResponsesAssistantInputContent = OpenAIResponsesInputContent | OpenAIResponsesOutputRefusal;
 
 // Explicit content breakpoints inherit their lifetime from
 // `prompt_cache_options.ttl`. The mode stays open-string for forward

packages/provider-codex/src/responses-lite.ts

@@ -132,7 +132,9 @@ const removeInputImageDetails = <T extends { type: string }>(parts: T[]): T[] =>
 const removeLiteImageDetail = (item: CanonicalOpenAIResponsesInputItem): CanonicalOpenAIResponsesInputItem => {
   if (item.type === 'message' && Array.isArray(item.content)) {
     const content = removeInputImageDetails(item.content);
-    return content === item.content ? item : { ...item, content };
+    // The role conditions `content`'s shape, so an assistant turn keeps its
+    // refusal arm while a client role cannot gain one here.
+    return content === item.content ? item : { ...item, content } as CanonicalOpenAIResponsesInputItem;
   }
   if ((item.type === 'function_call_output' || item.type === 'custom_tool_call_output') && Array.isArray(item.output)) {
     const output = removeInputImageDetails(item.output);

packages/provider-copilot/src/compaction.ts

@@ -8,7 +8,7 @@
 //   https://github.com/openai/codex/blob/3d805abdf09093bfa806f359a5adc6514766c420/codex-rs/core/src/compact_remote_v2.rs#L439-L501
 //   https://github.com/openai/codex/blob/3d805abdf09093bfa806f359a5adc6514766c420/codex-rs/utils/string/src/truncate.rs#L71-L74
 
-import { isOpenAIResponsesCompactionItem, createRandomOpenAIResponsesItemId, type OpenAIResponsesCompactionResultEx, type OpenAIResponsesCompactionTriggerItem, type OpenAIResponsesInputContent, type CanonicalOpenAIResponsesInputItem, type OpenAIResponsesInputMessageEx, type OpenAIResponsesOutputItemEx, type OpenAIResponsesResultEx } from '@floway-dev/protocols/openai-responses';
+import { isOpenAIResponsesCompactionItem, createRandomOpenAIResponsesItemId, type OpenAIResponsesCompactionResultEx, type OpenAIResponsesCompactionTriggerItem, type OpenAIResponsesAssistantInputContent, type CanonicalOpenAIResponsesInputItem, type CanonicalOpenAIResponsesText, type OpenAIResponsesInputMessageEx, type OpenAIResponsesOutputItemEx, type OpenAIResponsesResultEx } from '@floway-dev/protocols/openai-responses';
 
 export const COMPACTION_TRIGGER: OpenAIResponsesCompactionTriggerItem = { type: 'compaction_trigger' };
 
@@ -26,11 +26,7 @@ const RETAINED_BUDGET_TOKENS = 64_000;
 const APPROX_BYTES_PER_TOKEN = 4;
 const encoder = new TextEncoder();
 
-// Native compact echoes every text part — including assistant `output_text` —
-// as `input_text` so the client can resend `output` verbatim as next-turn
-// `input`. Normalize unconditionally; non-text content passes through and costs
-// 0 tokens against the retained budget.
-const normalizeContent = (content: OpenAIResponsesInputMessageEx['content']): OpenAIResponsesInputContent[] => {
+const normalizeContent = <Content extends OpenAIResponsesAssistantInputContent>(content: string | Content[]): (Content | CanonicalOpenAIResponsesText)[] => {
   if (typeof content === 'string') return [{ type: 'input_text', text: content }];
   return content.map(part => (part.type === 'output_text' ? { ...part, type: 'input_text' } : part));
 };
@@ -54,8 +50,10 @@ export const compactionResponse = (input: CanonicalOpenAIResponsesInputItem[], g
     const item = input[i];
     if (!isRetainedMessage(item)) continue;
 
-    const content = normalizeContent(item.content);
-    const tokens = content.reduce((sum, part) =>
+    const message = item.role === 'assistant'
+      ? { role: item.role, content: normalizeContent(item.content) }
+      : { role: item.role, content: normalizeContent(item.content) };
+    const tokens = message.content.reduce((sum, part) =>
       part.type === 'input_text'
         ? sum + Math.ceil(encoder.encode(part.text).length / APPROX_BYTES_PER_TOKEN)
         : sum, 0);
@@ -66,8 +64,7 @@ export const compactionResponse = (input: CanonicalOpenAIResponsesInputItem[], g
       type: 'message',
       id: createRandomOpenAIResponsesItemId('message'),
       status: item.status ?? 'completed',
-      role: item.role,
-      content,
+      ...message,
       ...(item.phase !== undefined ? { phase: item.phase } : {}),
     });
   }

packages/provider-copilot/src/interceptors/openai-chat-completions/compress-images.ts

@@ -1,10 +1,10 @@
 import { memoizedDataUrlCompressor } from '../image-compression.ts';
 import { targetSizeForOpenAIResponsesChat } from '../image-size.ts';
 import type { OpenAIChatCompletionsBoundaryCtx, CopilotOpenAIChatCompletionsBoundaryInterceptor } from './types.ts';
-import type { OpenAIChatCompletionsContentPart, OpenAIChatCompletionsMessage } from '@floway-dev/protocols/openai-chat-completions';
+import type { OpenAIChatCompletionsUserContentPart, OpenAIChatCompletionsMessage } from '@floway-dev/protocols/openai-chat-completions';
 import { isBase64ImageDataUrl } from '@floway-dev/provider';
 
-type OpenAIChatCompletionsImagePart = Extract<OpenAIChatCompletionsContentPart, { type: 'image_url' }>;
+type OpenAIChatCompletionsImagePart = Extract<OpenAIChatCompletionsUserContentPart, { type: 'image_url' }>;
 
 const compressInlineImages = async (ctx: OpenAIChatCompletionsBoundaryCtx): Promise<void> => {
   const targets: OpenAIChatCompletionsImagePart[] = [];
@@ -24,7 +24,7 @@ const compressInlineImages = async (ctx: OpenAIChatCompletionsBoundaryCtx): Prom
       compressedUrls.set(target, await compress(target.image_url.url));
     }),
   );
-  const hasCompressedImage = (part: OpenAIChatCompletionsContentPart): part is OpenAIChatCompletionsImagePart =>
+  const hasCompressedImage = (part: OpenAIChatCompletionsUserContentPart): part is OpenAIChatCompletionsImagePart =>
     part.type === 'image_url' && compressedUrls.has(part);
   const rewriteImage = (part: OpenAIChatCompletionsImagePart): OpenAIChatCompletionsImagePart => {
     const url = compressedUrls.get(part);

packages/provider-copilot/src/interceptors/openai-responses/compress-images.ts

@@ -1,7 +1,7 @@
 import { memoizedDataUrlCompressor } from '../image-compression.ts';
 import { targetSizeForOpenAIResponsesChat } from '../image-size.ts';
 import type { OpenAIResponsesBoundaryCtx } from './types.ts';
-import type { OpenAIResponsesInputContent, OpenAIResponsesInputImage, OpenAIResponsesToolOutputContent } from '@floway-dev/protocols/openai-responses';
+import type { CanonicalOpenAIResponsesInputItem, OpenAIResponsesInputContent, OpenAIResponsesInputImage, OpenAIResponsesOutputRefusal, OpenAIResponsesToolOutputContent } from '@floway-dev/protocols/openai-responses';
 import { isBase64ImageDataUrl } from '@floway-dev/provider';
 
 // A single client request can reach this boundary more than once — a
@@ -38,7 +38,7 @@ const compressInlineImages = async (ctx: OpenAIResponsesBoundaryCtx): Promise<vo
       compressedUrls.set(target.part, await compress(target.imageUrl));
     }),
   );
-  const hasCompressedImage = (part: OpenAIResponsesInputContent): part is CompressibleImagePart =>
+  const hasCompressedImage = (part: OpenAIResponsesInputContent | OpenAIResponsesOutputRefusal): part is CompressibleImagePart =>
     part.type === 'input_image' && compressedUrls.has(part as CompressibleImagePart);
   const rewriteImage = (part: CompressibleImagePart): CompressibleImagePart => {
     const imageUrl = compressedUrls.get(part);
@@ -51,15 +51,15 @@ const compressInlineImages = async (ctx: OpenAIResponsesBoundaryCtx): Promise<vo
     });
     return rewritten;
   };
-  const rewriteParts = <TPart extends OpenAIResponsesInputContent | OpenAIResponsesToolOutputContent>(parts: TPart[]): TPart[] =>
+  const rewriteParts = <TPart extends OpenAIResponsesInputContent | OpenAIResponsesOutputRefusal | OpenAIResponsesToolOutputContent>(parts: TPart[]): TPart[] =>
     parts.map(part => hasCompressedImage(part) ? rewriteImage(part) as TPart : part);
 
   ctx.payload = {
     ...ctx.payload,
     input: ctx.payload.input.map(item => {
       if (item.type === 'message' && Array.isArray(item.content)) {
         return item.content.some(hasCompressedImage)
-          ? { ...item, content: rewriteParts(item.content) }
+          ? { ...item, content: rewriteParts(item.content) } as CanonicalOpenAIResponsesInputItem
           : item;
       }
       if ((item.type === 'function_call_output' || item.type === 'custom_tool_call_output') && Array.isArray(item.output)) {

packages/translate/src/protocols/openai-chat-completions/via-openai-responses/content.ts

@@ -1,20 +1,20 @@
 import { TranslatorInputError } from '../../../translator-input-error.ts';
-import type { OpenAIChatCompletionsContentPart } from '@floway-dev/protocols/openai-chat-completions';
+import type { OpenAIChatCompletionsUserContentPart } from '@floway-dev/protocols/openai-chat-completions';
 import type { OpenAIResponsesInputContent } from '@floway-dev/protocols/openai-responses';
 
 // OpenAI Chat Completions and OpenAI Responses text arrays are transport fragments of one message, not
 // paragraph blocks. Preserve the existing no-separator flattening.
-const contentPartText = (part: OpenAIChatCompletionsContentPart | OpenAIResponsesInputContent): string | null => (part.type === 'text' || part.type === 'input_text' || part.type === 'output_text' ? part.text : null);
+const contentPartText = (part: OpenAIChatCompletionsUserContentPart | OpenAIResponsesInputContent): string | null => (part.type === 'text' || part.type === 'input_text' || part.type === 'output_text' ? part.text : null);
 
-const contentPartsToText = (parts: readonly (OpenAIChatCompletionsContentPart | OpenAIResponsesInputContent)[]): string =>
+const contentPartsToText = (parts: readonly (OpenAIChatCompletionsUserContentPart | OpenAIResponsesInputContent)[]): string =>
   parts
     .map(contentPartText)
     .filter((text): text is string => text !== null)
     .join('');
 
-export const openaiChatCompletionsContentToText = (content: string | OpenAIChatCompletionsContentPart[] | null | undefined): string => (typeof content === 'string' ? content : Array.isArray(content) ? contentPartsToText(content) : '');
+export const openaiChatCompletionsContentToText = (content: string | OpenAIChatCompletionsUserContentPart[] | null | undefined): string => (typeof content === 'string' ? content : Array.isArray(content) ? contentPartsToText(content) : '');
 
-export const openaiChatCompletionsContentToOpenAIResponsesInputContent = (content: string | OpenAIChatCompletionsContentPart[] | null | undefined): string | OpenAIResponsesInputContent[] => {
+export const openaiChatCompletionsContentToOpenAIResponsesInputContent = (content: string | OpenAIChatCompletionsUserContentPart[] | null | undefined): string | OpenAIResponsesInputContent[] => {
   if (typeof content === 'string') return content;
   if (!Array.isArray(content) || content.length === 0) return '';
 
@@ -23,8 +23,6 @@ export const openaiChatCompletionsContentToOpenAIResponsesInputContent = (conten
       switch (part.type) {
       case 'text':
         return { type: 'input_text', text: part.text };
-      case 'refusal':
-        return { type: 'refusal', refusal: part.refusal };
       case 'input_audio':
         throw new TranslatorInputError('Cannot translate input_audio content to OpenAI Responses.');
       case 'file':

packages/translate/src/protocols/openai-chat-completions/via-openai-responses/request.ts

@@ -7,7 +7,7 @@ import type { SidecarCodec } from '../../../types.ts';
 import { partitionOpenAIChatCompletionsTurns } from '../as-source/conversation-turns.ts';
 import { collectOpenAIChatCompletionsReplayContents, hasOpenAIChatCompletionsReasoning, findOpenAIChatCompletionsSidecarCarriers, verifyOpenAIChatCompletionsTurnDigest } from '../as-source/round-trip.ts';
 import type { OpenAIChatCompletionsAssistantMessage, OpenAIChatCompletionsMessage, OpenAIChatCompletionsPayload, OpenAIChatCompletionsTool } from '@floway-dev/protocols/openai-chat-completions';
-import type { CanonicalOpenAIResponsesPayload, OpenAIResponsesInputContent, CanonicalOpenAIResponsesInputItem, OpenAIResponsesTool, OpenAIResponsesToolChoice } from '@floway-dev/protocols/openai-responses';
+import type { CanonicalOpenAIResponsesPayload, OpenAIResponsesAssistantInputContent, CanonicalOpenAIResponsesInputItem, OpenAIResponsesTool, OpenAIResponsesToolChoice } from '@floway-dev/protocols/openai-responses';
 
 const translateChatTools = (tools?: OpenAIChatCompletionsTool[] | null): OpenAIResponsesTool[] =>
   tools?.length
@@ -36,8 +36,8 @@ const translateChatToolChoice = (choice: NonNullable<OpenAIChatCompletionsPayloa
   };
 };
 
-const translateAssistantContent = (message: OpenAIChatCompletionsAssistantMessage): OpenAIResponsesInputContent[] => {
-  const content: OpenAIResponsesInputContent[] = [];
+const translateAssistantContent = (message: OpenAIChatCompletionsAssistantMessage): OpenAIResponsesAssistantInputContent[] => {
+  const content: OpenAIResponsesAssistantInputContent[] = [];
   let hasRefusalPart = false;
 
   if (typeof message.content === 'string') {

packages/translate/src/protocols/openai-responses/via-anthropic-messages/request.ts

@@ -136,8 +136,6 @@ const translateToolOutput = async (output: string | OpenAIResponsesInputContent[
       blocks.push(image);
     } else if (part.type === 'input_file') {
       throw new TranslatorInputError('Cannot translate input_file tool output to Anthropic Messages.');
-    } else if (part.type === 'refusal') {
-      throw new TranslatorInputError('Cannot translate refusal content in a tool output to Anthropic Messages.');
     } else {
       blocks.push({ type: 'text', text: part.text });
     }