init claude-code

constants/systemPromptSections.ts

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+import {
+  clearBetaHeaderLatches,
+  clearSystemPromptSectionState,
+  getSystemPromptSectionCache,
+  setSystemPromptSectionCacheEntry,
+} from '../bootstrap/state.js'
+
+type ComputeFn = () => string | null | Promise<string | null>
+
+type SystemPromptSection = {
+  name: string
+  compute: ComputeFn
+  cacheBreak: boolean
+}
+
+/**
+ * Create a memoized system prompt section.
+ * Computed once, cached until /clear or /compact.
+ */
+export function systemPromptSection(
+  name: string,
+  compute: ComputeFn,
+): SystemPromptSection {
+  return { name, compute, cacheBreak: false }
+}
+
+/**
+ * Create a volatile system prompt section that recomputes every turn.
+ * This WILL break the prompt cache when the value changes.
+ * Requires a reason explaining why cache-breaking is necessary.
+ */
+export function DANGEROUS_uncachedSystemPromptSection(
+  name: string,
+  compute: ComputeFn,
+  _reason: string,
+): SystemPromptSection {
+  return { name, compute, cacheBreak: true }
+}
+
+/**
+ * Resolve all system prompt sections, returning prompt strings.
+ */
+export async function resolveSystemPromptSections(
+  sections: SystemPromptSection[],
+): Promise<(string | null)[]> {
+  const cache = getSystemPromptSectionCache()
+
+  return Promise.all(
+    sections.map(async s => {
+      if (!s.cacheBreak && cache.has(s.name)) {
+        return cache.get(s.name) ?? null
+      }
+      const value = await s.compute()
+      setSystemPromptSectionCacheEntry(s.name, value)
+      return value
+    }),
+  )
+}
+
+/**
+ * Clear all system prompt section state. Called on /clear and /compact.
+ * Also resets beta header latches so a fresh conversation gets fresh
+ * evaluation of AFK/fast-mode/cache-editing headers.
+ */
+export function clearSystemPromptSections(): void {
+  clearSystemPromptSectionState()
+  clearBetaHeaderLatches()
+}