diff --git a/index.mjs b/index.mjs
index 3105b69..d108236 100644
--- a/index.mjs
+++ b/index.mjs
@@ -84,7 +84,7 @@ export async function AnthropicAuthPlugin({ client }) {
       async loader(getAuth, provider) {
         const auth = await getAuth();
         if (auth.type === "oauth") {
-          // zero out cost for max plan
+          // zero out cost for max plan and cap context to 200k (1M beta not available for OAuth)
           for (const model of Object.values(provider.models)) {
             model.cost = {
               input: 0,
@@ -94,6 +94,7 @@ export async function AnthropicAuthPlugin({ client }) {
                 write: 0,
               },
             };
+            model.limit.context = Math.min(model.limit.context, 200_000);
           }
           return {
             apiKey: "",
@@ -171,7 +172,8 @@ export async function AnthropicAuthPlugin({ client }) {
               const incomingBetasList = incomingBeta
                 .split(",")
                 .map((b) => b.trim())
-                .filter(Boolean);
+                .filter(Boolean)
+                .filter((b) => !b.startsWith("context-1m"));
 
               const requiredBetas = [
                 "oauth-2025-04-20",