fix: use model cache context flag for runtime context limits

src/hooks/context-window-monitor.ts

@@ -2,13 +2,17 @@ import type { PluginInput } from "@opencode-ai/plugin"
 import { createSystemDirective, SystemDirectiveTypes } from "../shared/system-directive"
 
 const ANTHROPIC_DISPLAY_LIMIT = 1_000_000
-const ANTHROPIC_ACTUAL_LIMIT =
-  process.env.ANTHROPIC_1M_CONTEXT === "true" ||
-  process.env.VERTEX_ANTHROPIC_1M_CONTEXT === "true"
-    ? 1_000_000
-    : 200_000
+const DEFAULT_ANTHROPIC_ACTUAL_LIMIT = 200_000
 const CONTEXT_WARNING_THRESHOLD = 0.70
 
+function getAnthropicActualLimit(anthropicContext1MEnabled: boolean): number {
+  return anthropicContext1MEnabled ||
+    process.env.ANTHROPIC_1M_CONTEXT === "true" ||
+    process.env.VERTEX_ANTHROPIC_1M_CONTEXT === "true"
+    ? 1_000_000
+    : DEFAULT_ANTHROPIC_ACTUAL_LIMIT
+}
+
 const CONTEXT_REMINDER = `${createSystemDirective(SystemDirectiveTypes.CONTEXT_WINDOW_MONITOR)}
 
 You are using Anthropic Claude with 1M context window.
@@ -31,7 +35,10 @@ function isAnthropicProvider(providerID: string): boolean {
   return providerID === "anthropic" || providerID === "google-vertex-anthropic"
 }
 
-export function createContextWindowMonitorHook(_ctx: PluginInput) {
+export function createContextWindowMonitorHook(
+  _ctx: PluginInput,
+  anthropicContext1MEnabled = false,
+) {
   const remindedSessions = new Set<string>()
   const tokenCache = new Map<string, CachedTokenState>()
 
@@ -51,7 +58,8 @@ export function createContextWindowMonitorHook(_ctx: PluginInput) {
     const lastTokens = cached.tokens
     const totalInputTokens = (lastTokens?.input ?? 0) + (lastTokens?.cache?.read ?? 0)
 
-    const actualUsagePercentage = totalInputTokens / ANTHROPIC_ACTUAL_LIMIT
+    const actualUsagePercentage =
+      totalInputTokens / getAnthropicActualLimit(anthropicContext1MEnabled)
 
     if (actualUsagePercentage < CONTEXT_WARNING_THRESHOLD) return
 

src/hooks/directory-agents-injector/hook.ts

@@ -27,9 +27,12 @@ interface EventInput {
   };
 }
 
-export function createDirectoryAgentsInjectorHook(ctx: PluginInput) {
+export function createDirectoryAgentsInjectorHook(
+  ctx: PluginInput,
+  anthropicContext1MEnabled?: boolean,
+) {
   const sessionCaches = new Map<string, Set<string>>();
-  const truncator = createDynamicTruncator(ctx);
+  const truncator = createDynamicTruncator(ctx, anthropicContext1MEnabled);
 
   const toolExecuteAfter = async (input: ToolExecuteInput, output: ToolExecuteOutput) => {
     const toolName = input.tool.toLowerCase();

src/hooks/directory-readme-injector/hook.ts

@@ -27,9 +27,12 @@ interface EventInput {
   };
 }
 
-export function createDirectoryReadmeInjectorHook(ctx: PluginInput) {
+export function createDirectoryReadmeInjectorHook(
+  ctx: PluginInput,
+  anthropicContext1MEnabled?: boolean,
+) {
   const sessionCaches = new Map<string, Set<string>>();
-  const truncator = createDynamicTruncator(ctx);
+  const truncator = createDynamicTruncator(ctx, anthropicContext1MEnabled);
 
   const toolExecuteAfter = async (input: ToolExecuteInput, output: ToolExecuteOutput) => {
     const toolName = input.tool.toLowerCase();

src/hooks/preemptive-compaction.ts

@@ -2,11 +2,13 @@ import { log } from "../shared/logger"
 
 const DEFAULT_ACTUAL_LIMIT = 200_000
 
-const ANTHROPIC_ACTUAL_LIMIT =
-  process.env.ANTHROPIC_1M_CONTEXT === "true" ||
-  process.env.VERTEX_ANTHROPIC_1M_CONTEXT === "true"
+function getAnthropicActualLimit(anthropicContext1MEnabled: boolean): number {
+  return anthropicContext1MEnabled ||
+    process.env.ANTHROPIC_1M_CONTEXT === "true" ||
+    process.env.VERTEX_ANTHROPIC_1M_CONTEXT === "true"
     ? 1_000_000
     : DEFAULT_ACTUAL_LIMIT
+}
 
 const PREEMPTIVE_COMPACTION_THRESHOLD = 0.78
 
@@ -43,7 +45,10 @@ type PluginInput = {
   directory: string
 }
 
-export function createPreemptiveCompactionHook(ctx: PluginInput) {
+export function createPreemptiveCompactionHook(
+  ctx: PluginInput,
+  anthropicContext1MEnabled = false,
+) {
   const compactionInProgress = new Set<string>()
   const compactedSessions = new Set<string>()
   const tokenCache = new Map<string, CachedCompactionState>()
@@ -60,7 +65,7 @@ export function createPreemptiveCompactionHook(ctx: PluginInput) {
 
     const actualLimit =
       isAnthropicProvider(cached.providerID)
-        ? ANTHROPIC_ACTUAL_LIMIT
+        ? getAnthropicActualLimit(anthropicContext1MEnabled)
         : DEFAULT_ACTUAL_LIMIT
 
     const lastTokens = cached.tokens

src/hooks/rules-injector/hook.ts

@@ -29,8 +29,11 @@ interface EventInput {
 
 const TRACKED_TOOLS = ["read", "write", "edit", "multiedit"];
 
-export function createRulesInjectorHook(ctx: PluginInput) {
-  const truncator = createDynamicTruncator(ctx);
+export function createRulesInjectorHook(
+  ctx: PluginInput,
+  anthropicContext1MEnabled?: boolean,
+) {
+  const truncator = createDynamicTruncator(ctx, anthropicContext1MEnabled);
   const { getSessionCache, clearSessionCache } = createSessionCacheStore();
   const { processFilePathForInjection } = createRuleInjectionProcessor({
     workspaceDirectory: ctx.directory,

src/hooks/tool-output-truncator.ts

@@ -27,11 +27,12 @@ const TOOL_SPECIFIC_MAX_TOKENS: Record<string, number> = {
 }
 
 interface ToolOutputTruncatorOptions {
+  anthropicContext1MEnabled?: boolean
   experimental?: ExperimentalConfig
 }
 
 export function createToolOutputTruncatorHook(ctx: PluginInput, options?: ToolOutputTruncatorOptions) {
-  const truncator = createDynamicTruncator(ctx)
+  const truncator = createDynamicTruncator(ctx, options?.anthropicContext1MEnabled)
   const truncateAll = options?.experimental?.truncate_all_tool_outputs ?? false
 
   const toolExecuteAfter = async (