fix: preserve model name suffixes (-fast, -high, etc.) in API responses

Response model name was losing suffixes because it used the stripped base
model ID from parseModelName() instead of reconstructing with suffixes.
Also adds `none` to EFFORT_SUFFIXES (gpt-5.4 supports none reasoning).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/models/model-store.ts

@@ -195,7 +195,7 @@ export interface ParsedModelName {
 }
 
 const SERVICE_TIER_SUFFIXES = new Set(["fast", "flex"]);
-const EFFORT_SUFFIXES = new Set(["minimal", "low", "medium", "high", "xhigh"]);
+const EFFORT_SUFFIXES = new Set(["none", "minimal", "low", "medium", "high", "xhigh"]);
 
 /**
  * Parse a model name that may contain embedded suffixes for service_tier and reasoning_effort.
@@ -243,6 +243,14 @@ export function parseModelName(input: string): ParsedModelName {
   return { modelId, serviceTier, reasoningEffort };
 }
 
+/** Reconstruct display model name: resolved modelId + any parsed suffixes. */
+export function buildDisplayModelName(parsed: ParsedModelName): string {
+  let name = parsed.modelId;
+  if (parsed.reasoningEffort) name += `-${parsed.reasoningEffort}`;
+  if (parsed.serviceTier) name += `-${parsed.serviceTier}`;
+  return name;
+}
+
 // ── Getters ────────────────────────────────────────────────────────
 
 /**

src/routes/chat.ts

@@ -9,6 +9,7 @@ import {
   collectCodexResponse,
 } from "../translation/codex-to-openai.js";
 import { getConfig } from "../config.js";
+import { parseModelName, buildDisplayModelName } from "../models/model-store.js";
 import {
   handleProxyRequest,
   type FormatAdapter,
@@ -122,6 +123,7 @@ export function createChatRoutes(
     const req = parsed.data;
 
     const codexRequest = translateToCodexRequest(req);
+    const displayModel = buildDisplayModelName(parseModelName(req.model));
     const wantReasoning = !!req.reasoning_effort;
 
     return handleProxyRequest(
@@ -130,7 +132,7 @@ export function createChatRoutes(
       cookieJar,
       {
         codexRequest,
-        model: codexRequest.model,
+        model: displayModel,
         isStreaming: req.stream,
       },
       makeOpenAIFormat(wantReasoning),

src/routes/messages.ts

@@ -16,6 +16,7 @@ import {
   collectCodexToAnthropicResponse,
 } from "../translation/codex-to-anthropic.js";
 import { getConfig } from "../config.js";
+import { parseModelName, buildDisplayModelName } from "../models/model-store.js";
 import {
   handleProxyRequest,
   type FormatAdapter,
@@ -104,7 +105,7 @@ export function createMessagesRoutes(
       cookieJar,
       {
         codexRequest,
-        model: req.model,
+        model: buildDisplayModelName(parseModelName(req.model)),
         isStreaming: req.stream,
       },
       makeAnthropicFormat(wantThinking),

src/routes/responses.ts

@@ -12,7 +12,7 @@ import type { CookieJar } from "../proxy/cookie-jar.js";
 import type { ProxyPool } from "../proxy/proxy-pool.js";
 import type { CodexResponsesRequest, CodexInputItem, CodexApi } from "../proxy/codex-api.js";
 import { getConfig } from "../config.js";
-import { parseModelName, resolveModelId, getModelInfo } from "../models/model-store.js";
+import { parseModelName, resolveModelId, getModelInfo, buildDisplayModelName } from "../models/model-store.js";
 import { EmptyResponseError } from "../translation/codex-event-extractor.js";
 import {
   handleProxyRequest,
@@ -215,6 +215,7 @@ export function createResponsesRoutes(
     const rawModel = typeof body.model === "string" ? body.model : "codex";
     const parsed = parseModelName(rawModel);
     const modelId = resolveModelId(parsed.modelId);
+    const displayModel = buildDisplayModelName(parsed);
     const modelInfo = getModelInfo(modelId);
 
     // Build CodexResponsesRequest
@@ -269,7 +270,7 @@ export function createResponsesRoutes(
       cookieJar,
       {
         codexRequest,
-        model: modelId,
+        model: displayModel,
         isStreaming: clientWantsStream,
       },
       PASSTHROUGH_FORMAT,