diff --git a/src/lib/modelCapabilities.ts b/src/lib/modelCapabilities.ts
index e3e6052f9d..68d89274b9 100644
--- a/src/lib/modelCapabilities.ts
+++ b/src/lib/modelCapabilities.ts
@@ -11,6 +11,7 @@ import {
   type ModelSpec,
 } from "@/shared/constants/modelSpecs";
 import { getSyncedCapability } from "@/lib/modelsDevSync";
+import { MODELS_DEV_PROVIDER_MAP } from "@/lib/modelsDevSync/transform";
 import { getModelContextOverride } from "@/lib/db/modelContextOverrides";
 import { getModelCapabilityOverride } from "@/lib/db/modelCapabilityOverrides";
 import { isVisionModelId } from "@/shared/constants/visionModels";
@@ -227,6 +228,20 @@ function stripLatestAlias(modelId: string | null): string | null {
   return stripped && stripped !== modelId ? stripped : null;
 }
 
+function reverseModelsDevProviders(provider: string): string[] {
+  // models.dev may store capabilities under a different OmniRoute provider id
+  // that also maps from the same upstream models.dev provider. Build reverse
+  // candidates from MODELS_DEV_PROVIDER_MAP (e.g. openai ↔ cx).
+  const out = new Set<string>();
+  for (const [modelsDevId, omniIds] of Object.entries(MODELS_DEV_PROVIDER_MAP)) {
+    if (omniIds.includes(provider) || modelsDevId === provider) {
+      out.add(modelsDevId);
+      for (const id of omniIds) out.add(id);
+    }
+  }
+  return [...out];
+}
+
 function getSyncedCapabilityForResolved(
   provider: string | null,
   model: string | null,
@@ -234,35 +249,36 @@ function getSyncedCapabilityForResolved(
 ): SyncedCapabilities {
   if (!provider || !model) return null;
 
-  const direct = getSyncedCapability(provider, model);
-  if (direct) return direct;
+  const modelCandidates = Array.from(
+    new Set(
+      [model, rawModel, getStaticSpecCanonicalModelId(model, rawModel)]
+        .filter((value): value is string => typeof value === "string" && value.length > 0)
+        .flatMap((candidate) => {
+          const values = [candidate];
+          const stripped = stripLatestAlias(candidate);
+          if (stripped) values.push(stripped);
+          // models.dev often stores OpenAI-family specialty models as qualified
+          // ids under another mapped provider, e.g. vercel + "openai/whisper-1".
+          if (!candidate.includes("/")) {
+            values.push(`${provider}/${candidate}`);
+          }
+          return values;
+        })
+    )
+  );
 
-  if (rawModel && rawModel !== model) {
-    const raw = getSyncedCapability(provider, rawModel);
-    if (raw) return raw;
-  }
+  // Include common host providers that re-publish OpenAI specialty models under
+  // qualified ids (observed: vercel/openai/whisper-1, vercel/openai/tts-1).
+  const providerCandidates = Array.from(
+    new Set([provider, ...reverseModelsDevProviders(provider), "vercel"])
+  );
 
-  const canonical = getStaticSpecCanonicalModelId(model, rawModel);
-  if (canonical && canonical !== model) {
-    const byCanonical = getSyncedCapability(provider, canonical);
-    if (byCanonical) return byCanonical;
-  }
-
-  // #4073: models.dev catalogs some `-latest` aliases under their short id
-  // (e.g. Mistral `pixtral-12b-latest` is stored as `pixtral-12b`). When every
-  // exact lookup above misses, retry once with a trailing `-latest` stripped so
-  // the synced metadata (`attachment` / image modalities) still wins over the
-  // last-resort #4071 model-id heuristic. Only fires as a fallback, so models
-  // whose `-latest` id IS stored verbatim (e.g. `pixtral-large-latest`) keep
-  // resolving directly above.
-  for (const candidate of [model, rawModel]) {
-    const base = stripLatestAlias(candidate);
-    if (base && base !== model && base !== rawModel) {
-      const byAlias = getSyncedCapability(provider, base);
-      if (byAlias) return byAlias;
+  for (const prov of providerCandidates) {
+    for (const mid of modelCandidates) {
+      const found = getSyncedCapability(prov, mid);
+      if (found) return found;
     }
   }
-
   return null;
 }
 
diff --git a/tests/unit/modelsdev-specialty-keying-8017.test.ts b/tests/unit/modelsdev-specialty-keying-8017.test.ts
new file mode 100644
index 0000000000..edcf9a6178
--- /dev/null
+++ b/tests/unit/modelsdev-specialty-keying-8017.test.ts
@@ -0,0 +1,112 @@
+import assert from "node:assert/strict";
+import { describe, it, before, after } from "node:test";
+import { getResolvedModelCapabilities } from "../../src/lib/modelCapabilities.ts";
+import {
+  saveModelsDevCapabilities,
+  clearModelsDevCapabilities,
+  type CapabilitiesByProvider,
+} from "../../src/lib/modelsDevSync.ts";
+
+describe("models.dev specialty key resolution (#8017)", () => {
+  before(() => {
+    // Store specialty rows the way production models.dev currently does:
+    // under provider=vercel with qualified openai/* model ids.
+    const capabilities: CapabilitiesByProvider = {
+      vercel: {
+        "openai/whisper-1": {
+          tool_call: false,
+          reasoning: false,
+          attachment: false,
+          structured_output: null,
+          temperature: true,
+          modalities_input: '["audio"]',
+          modalities_output: '["text"]',
+          knowledge_cutoff: null,
+          release_date: null,
+          last_updated: null,
+          status: null,
+          family: null,
+          open_weights: null,
+          limit_context: 0,
+          limit_input: null,
+          limit_output: 0,
+          interleaved_field: null,
+          last_synced: new Date().toISOString(),
+        },
+        "openai/tts-1": {
+          tool_call: false,
+          reasoning: false,
+          attachment: false,
+          structured_output: null,
+          temperature: true,
+          modalities_input: '["text"]',
+          modalities_output: '["audio"]',
+          knowledge_cutoff: null,
+          release_date: null,
+          last_updated: null,
+          status: null,
+          family: null,
+          open_weights: null,
+          limit_context: 0,
+          limit_input: null,
+          limit_output: 0,
+          interleaved_field: null,
+          last_synced: new Date().toISOString(),
+        },
+      },
+      openai: {
+        "gpt-4o": {
+          tool_call: true,
+          reasoning: false,
+          attachment: true,
+          structured_output: true,
+          temperature: true,
+          modalities_input: '["text","image","pdf"]',
+          modalities_output: '["text"]',
+          knowledge_cutoff: null,
+          release_date: null,
+          last_updated: null,
+          status: null,
+          family: null,
+          open_weights: null,
+          limit_context: 128000,
+          limit_input: null,
+          limit_output: 16384,
+          interleaved_field: null,
+          last_synced: new Date().toISOString(),
+        },
+      },
+    };
+    saveModelsDevCapabilities(capabilities);
+  });
+
+  after(() => {
+    try {
+      clearModelsDevCapabilities();
+    } catch {
+      // ignore cleanup failures in unit isolation
+    }
+  });
+
+  it("resolves openai/whisper-1 against vercel/openai/whisper-1", () => {
+    const md = getResolvedModelCapabilities({ provider: "openai", model: "whisper-1" });
+    assert.deepEqual(md.modalitiesInput, ["audio"]);
+    assert.deepEqual(md.modalitiesOutput, ["text"]);
+    assert.equal(md.toolCalling, false);
+    assert.equal(md.reasoning, false);
+  });
+
+  it("resolves openai/tts-1 against vercel/openai/tts-1", () => {
+    const md = getResolvedModelCapabilities({ provider: "openai", model: "tts-1" });
+    assert.deepEqual(md.modalitiesInput, ["text"]);
+    assert.deepEqual(md.modalitiesOutput, ["audio"]);
+    assert.equal(md.toolCalling, false);
+  });
+
+  it("still resolves direct openai/gpt-4o keys", () => {
+    const md = getResolvedModelCapabilities({ provider: "openai", model: "gpt-4o" });
+    assert.equal(md.toolCalling, true);
+    assert.equal(md.contextWindow, 128000);
+    assert.deepEqual(md.modalitiesInput, ["text", "image", "pdf"]);
+  });
+});