diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index a02a017e77c..21f03a2720a 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -621,6 +621,72 @@ export namespace Provider {
     })
   export type Info = z.infer<typeof Info>
 
+  const BEDROCK_OPUS_4_6 = "claude-opus-4-6"
+  const BEDROCK_1M_BETA = "context-1m-2025-08-07"
+  const BEDROCK_CONTEXT_200K = 200_000
+  const BEDROCK_CONTEXT_1M = 1_000_000
+
+  function splitBedrockOpus46(providerID: string, models: Record<string, Model>) {
+    if (providerID !== "amazon-bedrock") return
+
+    for (const [id, model] of Object.entries(models)) {
+      if (!model.api.id.includes(BEDROCK_OPUS_4_6)) continue
+      if (id.endsWith("-1m")) continue
+
+      const name = model.name.replace(/\s+\((200K|1M Experimental)\)$/i, "")
+      const opts = { ...model.options }
+      const raw = opts["anthropicBeta"]
+      const base = (Array.isArray(raw) ? raw : typeof raw === "string" ? [raw] : []).filter(
+        (item): item is string => typeof item === "string",
+      )
+
+      delete opts["anthropicBeta"]
+
+      model.name = `${name} (200K)`
+      model.options = opts
+      model.limit = {
+        ...model.limit,
+        context: Math.min(model.limit.context, BEDROCK_CONTEXT_200K),
+      }
+
+      const nextID = `${id}-1m`
+      const next = models[nextID]
+
+      if (next) {
+        const list = (Array.isArray(next.options["anthropicBeta"]) ? next.options["anthropicBeta"] : []).filter(
+          (item): item is string => typeof item === "string",
+        )
+
+        next.name = `${name} (1M Experimental)`
+        next.status = "beta"
+        next.limit = {
+          ...next.limit,
+          context: Math.max(next.limit.context, BEDROCK_CONTEXT_1M),
+        }
+        next.options = {
+          ...next.options,
+          anthropicBeta: [...new Set([...list, ...base, BEDROCK_1M_BETA])],
+        }
+        continue
+      }
+
+      models[nextID] = {
+        ...model,
+        id: nextID,
+        name: `${name} (1M Experimental)`,
+        status: "beta",
+        limit: {
+          ...model.limit,
+          context: Math.max(model.limit.context, BEDROCK_CONTEXT_1M),
+        },
+        options: {
+          ...model.options,
+          anthropicBeta: [...new Set([...base, BEDROCK_1M_BETA])],
+        },
+      }
+    }
+  }
+
   function fromModelsDevModel(provider: ModelsDev.Provider, model: ModelsDev.Model): Model {
     const m: Model = {
       id: model.id,
@@ -689,13 +755,16 @@ export namespace Provider {
   }
 
   export function fromModelsDevProvider(provider: ModelsDev.Provider): Info {
+    const models = mapValues(provider.models, (model) => fromModelsDevModel(provider, model))
+    splitBedrockOpus46(provider.id, models)
+
     return {
       id: provider.id,
       source: "custom",
       name: provider.name,
       env: provider.env ?? [],
       options: {},
-      models: mapValues(provider.models, (model) => fromModelsDevModel(provider, model)),
+      models,
     }
   }
 
diff --git a/packages/opencode/test/provider/provider.test.ts b/packages/opencode/test/provider/provider.test.ts
index 98cd49c02fd..7a002b4a45e 100644
--- a/packages/opencode/test/provider/provider.test.ts
+++ b/packages/opencode/test/provider/provider.test.ts
@@ -1407,6 +1407,89 @@ test("model headers are preserved", async () => {
   })
 })
 
+test("fromModelsDevProvider splits bedrock opus 4.6 into 200K and 1M variants", () => {
+  const provider = Provider.fromModelsDevProvider({
+    id: "amazon-bedrock",
+    name: "Amazon Bedrock",
+    env: [],
+    models: {
+      "us.anthropic.claude-opus-4-6-v1:0": {
+        id: "us.anthropic.claude-opus-4-6-v1:0",
+        name: "Claude Opus 4.6",
+        attachment: true,
+        reasoning: true,
+        tool_call: true,
+        temperature: true,
+        release_date: "2025-12-01",
+        limit: { context: 1_000_000, output: 64_000 },
+        options: {
+          anthropicBeta: ["existing-beta"],
+        },
+      },
+    },
+  })
+
+  const base = provider.models["us.anthropic.claude-opus-4-6-v1:0"]
+  const extended = provider.models["us.anthropic.claude-opus-4-6-v1:0-1m"]
+
+  expect(base).toBeDefined()
+  expect(extended).toBeDefined()
+
+  expect(base.name).toContain("(200K)")
+  expect(extended.name).toContain("(1M Experimental)")
+
+  expect(base.limit.context).toBe(200_000)
+  expect(extended.limit.context).toBe(1_000_000)
+
+  expect(base.options.anthropicBeta).toBeUndefined()
+  expect(extended.options.anthropicBeta).toEqual(expect.arrayContaining(["existing-beta", "context-1m-2025-08-07"]))
+
+  expect(extended.api.id).toBe(base.api.id)
+  expect(extended.status).toBe("beta")
+})
+
+test("bedrock custom opus 4.6 model is not auto-split", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            "amazon-bedrock": {
+              models: {
+                "anthropic.claude-opus-4-6-v1:0": {
+                  name: "Claude Opus 4.6",
+                  attachment: true,
+                  reasoning: true,
+                  tool_call: true,
+                  temperature: true,
+                  limit: { context: 1_000_000, output: 64_000 },
+                },
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const providers = await Provider.list()
+      const base = providers["amazon-bedrock"].models["anthropic.claude-opus-4-6-v1:0"]
+      const extended = providers["amazon-bedrock"].models["anthropic.claude-opus-4-6-v1:0-1m"]
+
+      expect(base).toBeDefined()
+      expect(extended).toBeUndefined()
+      expect(base.name).toBe("Claude Opus 4.6")
+      expect(base.limit.context).toBe(1_000_000)
+      expect(base.options.anthropicBeta).toBeUndefined()
+    },
+  })
+})
+
 test("provider env fallback - second env var used if first missing", async () => {
   await using tmp = await tmpdir({
     init: async (dir) => {