diff --git a/packages/core/src/models-dev.ts b/packages/core/src/models-dev.ts
index 31936e75c4..3e197b90e1 100644
--- a/packages/core/src/models-dev.ts
+++ b/packages/core/src/models-dev.ts
@@ -1,4 +1,4 @@
-import { Context, Duration, Effect, Layer, Option, Schedule, Schema, Semaphore } from "effect"
+import { Cause, Context, Duration, Effect, Layer, Option, Schedule, Schema, Semaphore } from "effect"
 import { HttpClient, HttpClientRequest } from "effect/unstable/http"
 import { ModelsDev } from "@opencode-ai/schema/models-dev"
 import { Money } from "@opencode-ai/schema/money"
@@ -612,7 +612,16 @@ export const layer = (options?: Options) =>
       const fetchAndWrite = Effect.fn("ModelsDev.fetchAndWrite")(function* () {
         const text = yield* fetchApi()
         const catalog = (yield* Schema.decodeUnknownEffect(CatalogJson)(text)) as Record<string, SourceProvider>
-        yield* kv.set(key, { updatedAt: Date.now(), body: text })
+        // Best-effort: a cache-write failure must never kill catalog
+        // population. The payload has outgrown some KV backends' per-value
+        // limits (Durable Object SQLite caps values at 2 MB and api.json
+        // passed it in Aug 2026); a boot without a cache hit just refetches.
+        yield* kv.set(key, { updatedAt: Date.now(), body: text }).pipe(
+          Effect.catchCauseIf(
+            (cause) => !Cause.hasInterruptsOnly(cause),
+            (cause) => Effect.logWarning("Failed to cache models.dev catalog", { cause }),
+          ),
+        )
         return catalog
       })
 
diff --git a/packages/core/test/models.test.ts b/packages/core/test/models.test.ts
index 43368d7d28..230bc767ba 100644
--- a/packages/core/test/models.test.ts
+++ b/packages/core/test/models.test.ts
@@ -185,6 +185,15 @@ const buildLayer = (state: Ref.Ref<MockState>, cache: MockCache, options: Models
     ]),
   )
 
+// Mirrors production KV backends whose writes die as defects (e.g. Durable
+// Object SQLite rejecting values over its 2 MB cap with EffectDrizzleQueryError).
+const makeFailingWriteKV = (cache: MockCache) =>
+  Layer.mock(KV.Service, {
+    get: (key) => Effect.sync(() => cache.values.get(key)),
+    set: () => Effect.die(new Error("Failed query: insert into \"kv\"")),
+    remove: (key) => Effect.sync(() => cache.values.delete(key)).pipe(Effect.asVoid),
+  })
+
 const makeCache = (): MockCache => ({ values: new Map() })
 
 const writeCacheText = (cache: MockCache, text: string, updatedAt = Date.now()) =>
@@ -248,6 +257,25 @@ describe("ModelsDev Service", () => {
     }),
   )
 
+  it.live("get() still populates the catalog when the KV cache write fails", () =>
+    Effect.gen(function* () {
+      const cache = makeCache()
+      const state = yield* Ref.make({ ...initialState, body: JSON.stringify(fixture2) })
+      const layer = Layer.fresh(
+        AppNodeBuilder.build(ModelsDev.node, [
+          [ModelsDev.node, ModelsDev.configured({ fetch: true })],
+          [LayerNodePlatform.httpClient, Layer.succeed(HttpClient.HttpClient, makeMockClient(state))],
+          [KV.node, makeFailingWriteKV(cache)],
+        ]),
+      )
+      const result = yield* ModelsDev.Service.use((s) => s.get()).pipe(Effect.provide(layer))
+      expect(result).toEqual(fixture2Snapshot)
+      expect(cache.values.has(cacheKey)).toBe(false)
+      const final = yield* Ref.get(state)
+      expect(final.calls.length).toBe(1)
+    }),
+  )
+
   it.live("uses the default models URL when the configured URL is empty", () =>
     Effect.gen(function* () {
       const cache = makeCache()