fix: update sessionEntry.contextTokens on model switch

ethanperezz · claude · ethanperezz · commit 3af6e634c10d · 2026-03-05T00:54:26.000-05:00
When switching models via inline directive, applyModelOverrideToSessionEntry updated the model/provider override but left contextTokens unchanged. This caused contextTokens to get stuck at a lower value after switching to a model with a smaller context window and back. Now persistInlineDirectives explicitly updates sessionEntry.contextTokens to match the new model's context window, keeping session state consistent. Fixes #35372 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
diff --git a/src/auto-reply/reply/directive-handling.persist.ts b/src/auto-reply/reply/directive-handling.persist.ts
@@ -173,6 +173,14 @@ export async function persistInlineDirectives(params: {
           });
           provider = resolved.ref.provider;
           model = resolved.ref.model;
+          // Update contextTokens to match the new model so session state
+          // reflects the correct context window after a model switch (#35372).
+          const newContextTokens =
+            agentCfg?.contextTokens ?? lookupContextTokens(model) ?? DEFAULT_CONTEXT_TOKENS;
+          if (sessionEntry.contextTokens !== newContextTokens) {
+            sessionEntry.contextTokens = newContextTokens;
+            updated = true;
+          }
           const nextLabel = `${provider}/${model}`;
           if (nextLabel !== initialModelLabel) {
             enqueueSystemEvent(formatModelSwitchEvent(nextLabel, resolved.alias), {
