fix(minimax): stop capping MiniMax-M3 / M2.7 max_tokens at 8192 (#3141) (#3163)

MiniMax-M3 had no MODEL_SPECS entry and capitalized MiniMax-M2.7 missed
its lowercase spec (case-sensitive lookup) → both fell to the 8192 default
cap. Add the M3 spec (512K output), alias the capitalized ids, and make
getModelSpec lookups case-insensitive.

Co-authored-by: totaltube <totaltube@users.noreply.github.com>

src/shared/constants/modelSpecs.ts

@@ -310,12 +310,24 @@ export const MODEL_SPECS: Record<string, ModelSpec> = {
     supportsTools: true,
   },
 
+  // ── MiniMax M3 (1M context, 512K max output) ─────────────────────
+  // max output verified against MiniMax docs / OpenRouter / Artificial
+  // Analysis (Nov 2025 launch): 1,048,576-token context, up to 512K output.
+  "minimax-m3": {
+    maxOutputTokens: 512000,
+    contextWindow: 1048576,
+    supportsThinking: true,
+    supportsTools: true,
+    aliases: ["MiniMax-M3", "MiniMaxAI/MiniMax-M3"],
+  },
+
   // ── MiniMax M2.x (200K context family) ───────────────────────────
   "minimax-m2.7": {
     maxOutputTokens: 131072,
     contextWindow: 204800,
     supportsThinking: true,
     supportsTools: true,
+    aliases: ["MiniMax-M2.7", "MiniMaxAI/MiniMax-M2.7"],
   },
   "minimax-m2.5": {
     maxOutputTokens: 131072,
@@ -356,14 +368,23 @@ export const MODEL_SPECS: Record<string, ModelSpec> = {
 export function getModelSpec(modelId: string): ModelSpec | undefined {
   if (MODEL_SPECS[modelId]) return MODEL_SPECS[modelId];
 
-  // Buscas por alias
+  // Case-insensitive lookups: upstream model ids are often capitalized
+  // (e.g. "MiniMax-M2.7") while specs/aliases use lowercase ids (#3141).
+  const lower = modelId.toLowerCase();
+
+  // Exact match (case-insensitive)
   for (const [canonical, spec] of Object.entries(MODEL_SPECS)) {
-    if (spec.aliases?.includes(modelId)) return spec;
+    if (canonical.toLowerCase() === lower) return spec;
   }
 
-  // Prefix matching
+  // Buscas por alias (case-insensitive)
+  for (const [, spec] of Object.entries(MODEL_SPECS)) {
+    if (spec.aliases?.some((alias) => alias.toLowerCase() === lower)) return spec;
+  }
+
+  // Prefix matching (case-insensitive)
   for (const [key, spec] of Object.entries(MODEL_SPECS)) {
-    if (key !== "__default__" && modelId.startsWith(key)) return spec;
+    if (key !== "__default__" && lower.startsWith(key.toLowerCase())) return spec;
   }
 
   return undefined;

tests/unit/minimax-m3-maxtokens.test.ts

@@ -0,0 +1,80 @@
+/**
+ * tests/unit/minimax-m3-maxtokens.test.ts
+ *
+ * Regression for issue #3141 — "Omniroute sets max_tokens = 8192 for
+ * minimax/MiniMax-M3" (reporter @totaltube).
+ *
+ * minimax-coding / minimax route through the Claude translator, which calls
+ * fitThinkingToMaxTokens(model, callerMaxTokens, …) → capMaxOutputTokens().
+ * The caller's larger max_tokens was silently capped to the 8192
+ * MODEL_SPECS.__default__ ceiling because:
+ *   (a) MiniMax-M3 had no MODEL_SPECS entry at all, and the registry models
+ *       declare no maxOutputTokens, so resolution fell through to __default__;
+ *   (b) MiniMax-M2.7 (the upstream, capitalized id) never matched its existing
+ *       lowercase "minimax-m2.7" spec because getModelSpec was case-SENSITIVE.
+ *
+ * Both lookups must now resolve to the real family ceiling (well above 8192).
+ */
+
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-minimax-m3-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const modelCapabilities = await import("../../src/lib/modelCapabilities.ts");
+const { getModelSpec } = await import("../../src/shared/constants/modelSpecs.ts");
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+const DEFAULT_CAP = 8192;
+
+test("#3141 MiniMax-M3 max_tokens is not capped to the 8192 default", () => {
+  const cap = modelCapabilities.capMaxOutputTokens({ provider: "minimax", model: "MiniMax-M3" });
+  assert.ok(
+    cap > DEFAULT_CAP,
+    `expected MiniMax-M3 maxOutputTokens > ${DEFAULT_CAP}, got ${cap}`
+  );
+});
+
+test("#3141 MiniMaxAI/MiniMax-M3 (prefixed id) resolves above the 8192 default", () => {
+  const cap = modelCapabilities.capMaxOutputTokens({
+    provider: "minimax",
+    model: "MiniMaxAI/MiniMax-M3",
+  });
+  assert.ok(
+    cap > DEFAULT_CAP,
+    `expected MiniMaxAI/MiniMax-M3 maxOutputTokens > ${DEFAULT_CAP}, got ${cap}`
+  );
+});
+
+test("#3141 capitalized MiniMax-M2.7 resolves to its lowercase spec (case-insensitive)", () => {
+  const cap = modelCapabilities.capMaxOutputTokens({ provider: "minimax", model: "MiniMax-M2.7" });
+  assert.ok(
+    cap > DEFAULT_CAP,
+    `expected MiniMax-M2.7 maxOutputTokens > ${DEFAULT_CAP}, got ${cap}`
+  );
+});
+
+test("#3141 lowercase minimax-m2.7 spec is unchanged", () => {
+  const cap = modelCapabilities.capMaxOutputTokens({ provider: "minimax", model: "minimax-m2.7" });
+  assert.ok(
+    cap > DEFAULT_CAP,
+    `expected minimax-m2.7 maxOutputTokens > ${DEFAULT_CAP}, got ${cap}`
+  );
+});
+
+test("#3141 getModelSpec resolves MiniMax-M3 and capitalized M2.7 to family specs", () => {
+  assert.ok(getModelSpec("MiniMax-M3"), "MiniMax-M3 should have a spec");
+  assert.ok(
+    getModelSpec("MiniMax-M2.7"),
+    "capitalized MiniMax-M2.7 should resolve to the minimax-m2.7 spec"
+  );
+});