diff --git a/open-sse/translator/paramSupport.ts b/open-sse/translator/paramSupport.ts
index caad2ab5a3..85dcec35ae 100644
--- a/open-sse/translator/paramSupport.ts
+++ b/open-sse/translator/paramSupport.ts
@@ -63,7 +63,12 @@ const STRIP_RULES: StripRule[] = [
   // MoonshotAI/kimi-cli#1124), and by upstream decolua/9router#2460. Scoped to
   // OmniRoute's actual volcengine Kimi id (not a broad /kimi/i regex) so it
   // never clamps an unrelated future Kimi listing whose Ark cap may differ.
-  { provider: "volcengine", match: /^kimi-k2-5-260127$/, maxOutputCap: 32768, clampToModelMaxOutput: true },
+  {
+    provider: "volcengine",
+    match: /^kimi-k2-5-260127$/,
+    maxOutputCap: 32768,
+    clampToModelMaxOutput: true,
+  },
   // #7364: Z.AI's glm-4.6v vision endpoint enforces a 32768 max_tokens ceiling
   // server-side and 400s when a client sends a larger explicit max_tokens (e.g. a
   // client defaulting to 65536). Scoped to both wire paths that can reach this
@@ -75,6 +80,19 @@ const STRIP_RULES: StripRule[] = [
   // glmProvider.ts, maxOutputTokens: 32768, so clampToModelMaxOutput suffices).
   { provider: "zai", match: /^glm-4\.6v$/i, maxOutputCap: 32768 },
   { provider: "glm", match: /^glm-4\.6v$/i, clampToModelMaxOutput: true },
+  // Azure gpt-4o-mini deployments cap completion tokens at 16384 and 400 on
+  // anything larger: "max_tokens is too large: 32000. This model supports at
+  // most 16384 completion tokens". OmniRoute's own tool-calling floor
+  // (DEFAULT_MIN_TOKENS = 32000, applied by adjustMaxTokens) raises even a tiny
+  // explicit max_tokens to 32000 whenever tools are present, so every agentic
+  // client trips this on its first turn. PROVIDER_MAX_TOKENS is not the right
+  // lever here: it is provider-wide, and the same Azure resource also serves
+  // GPT-5 deployments whose ceiling is far higher. Azure deployment names are
+  // operator-chosen, hence a prefix match rather than an exact id, and the
+  // models are passthrough (no catalog maxOutputTokens for clampToModelMaxOutput
+  // to read), hence the fixed cap.
+  { provider: "azure-openai", match: /^gpt-4o-mini/i, maxOutputCap: 16384 },
+  { provider: "azure-ai", match: /^gpt-4o-mini/i, maxOutputCap: 16384 },
 ];
 
 function matches(rule: StripRule, model: string): boolean {
diff --git a/tests/unit/azure-max-output-clamp.test.ts b/tests/unit/azure-max-output-clamp.test.ts
new file mode 100644
index 0000000000..4b3e0a231d
--- /dev/null
+++ b/tests/unit/azure-max-output-clamp.test.ts
@@ -0,0 +1,58 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { stripUnsupportedParams } from "../../open-sse/translator/paramSupport.ts";
+
+/**
+ * Regression guard for the Azure gpt-4o-mini completion-token ceiling.
+ *
+ * Observed against a live Azure deployment:
+ *   azure-openai/gpt-4o-mini-dz
+ *     -> 400 "max_tokens is too large: 32000. This model supports at most
+ *            16384 completion tokens, whereas you provided 32000."
+ *
+ * The 32000 is OmniRoute's own doing: `adjustMaxTokens` raises any smaller
+ * max_tokens to DEFAULT_MIN_TOKENS (32000) whenever tools are present, so an
+ * agentic client trips this on its first turn even when it asked for far less.
+ */
+
+test("azure gpt-4o-mini clamps max_tokens to the 16384 ceiling", () => {
+  const out = stripUnsupportedParams("azure-openai", "gpt-4o-mini-dz", {
+    max_tokens: 32000,
+    messages: [],
+  }) as Record<string, unknown>;
+
+  assert.equal(out.max_tokens, 16384);
+});
+
+test("the clamp applies on the azure-ai wire path too", () => {
+  const out = stripUnsupportedParams("azure-ai", "gpt-4o-mini", {
+    max_completion_tokens: 32000,
+  }) as Record<string, unknown>;
+
+  assert.equal(out.max_completion_tokens, 16384);
+});
+
+test("a value already under the ceiling is left alone", () => {
+  const out = stripUnsupportedParams("azure-openai", "gpt-4o-mini", {
+    max_tokens: 800,
+  }) as Record<string, unknown>;
+
+  assert.equal(out.max_tokens, 800);
+});
+
+test("the clamp is scoped — larger Azure deployments keep their budget", () => {
+  const out = stripUnsupportedParams("azure-ai", "gpt-5.1", {
+    max_tokens: 32000,
+  }) as Record<string, unknown>;
+
+  assert.equal(out.max_tokens, 32000);
+});
+
+test("the clamp does not leak to gpt-4o-mini on other providers", () => {
+  const out = stripUnsupportedParams("openai", "gpt-4o-mini", {
+    max_tokens: 32000,
+  }) as Record<string, unknown>;
+
+  assert.equal(out.max_tokens, 32000);
+});