diff --git a/src/resources/extensions/gsd/bootstrap/register-hooks.ts b/src/resources/extensions/gsd/bootstrap/register-hooks.ts
index 7b131d86e..438d4d9b0 100644
--- a/src/resources/extensions/gsd/bootstrap/register-hooks.ts
+++ b/src/resources/extensions/gsd/bootstrap/register-hooks.ts
@@ -121,6 +121,8 @@ export function registerHooks(pi: ExtensionAPI): void {
       return { cancel: true };
     }
     const basePath = process.cwd();
+    const { ensureDbOpen } = await import("./dynamic-tools.js");
+    await ensureDbOpen();
     const state = await deriveState(basePath);
     if (!state.activeMilestone || !state.activeSlice || !state.activeTask) return;
     if (state.phase !== "executing") return;
diff --git a/src/resources/extensions/gsd/bootstrap/system-context.ts b/src/resources/extensions/gsd/bootstrap/system-context.ts
index bad24512d..3a336f9ee 100644
--- a/src/resources/extensions/gsd/bootstrap/system-context.ts
+++ b/src/resources/extensions/gsd/bootstrap/system-context.ts
@@ -293,6 +293,11 @@ function buildWorktreeContextBlock(): string {
 const RESUME_INTENT_PATTERNS = /^(continue|resume|ok|go|go ahead|proceed|keep going|carry on|next|yes|yeah|yep|sure|do it|let's go|pick up where you left off)$/;
 
 async function buildGuidedExecuteContextInjection(prompt: string, basePath: string): Promise<string | null> {
+  const ensureStateDbOpen = async () => {
+    const { ensureDbOpen } = await import("./dynamic-tools.js");
+    await ensureDbOpen();
+  };
+
   const executeMatch = prompt.match(/Execute the next task:\s+(T\d+)\s+\("([^"]+)"\)\s+in slice\s+(S\d+)\s+of milestone\s+(M\d+(?:-[a-z0-9]{6})?)/i);
   if (executeMatch) {
     const [, taskId, taskTitle, sliceId, milestoneId] = executeMatch;
@@ -302,6 +307,7 @@ async function buildGuidedExecuteContextInjection(prompt: string, basePath: stri
   const resumeMatch = prompt.match(/Resume interrupted work\.[\s\S]*?slice\s+(S\d+)\s+of milestone\s+(M\d+(?:-[a-z0-9]{6})?)/i);
   if (resumeMatch) {
     const [, sliceId, milestoneId] = resumeMatch;
+    await ensureStateDbOpen();
     const state = await deriveState(basePath);
     if (state.activeMilestone?.id === milestoneId && state.activeSlice?.id === sliceId && state.activeTask) {
       return buildTaskExecutionContextInjection(basePath, milestoneId, sliceId, state.activeTask.id, state.activeTask.title);
@@ -317,6 +323,7 @@ async function buildGuidedExecuteContextInjection(prompt: string, basePath: stri
   // replanning, gate evaluation, or other non-execution phases.
   const trimmed = prompt.trim().toLowerCase().replace(/[.!?,]+$/g, "");
   if (RESUME_INTENT_PATTERNS.test(trimmed)) {
+    await ensureStateDbOpen();
     const state = await deriveState(basePath);
     if (state.phase === "executing" && state.activeTask && state.activeMilestone && state.activeSlice) {
       return buildTaskExecutionContextInjection(
diff --git a/src/resources/extensions/gsd/tests/bootstrap-derive-state-db-open.test.ts b/src/resources/extensions/gsd/tests/bootstrap-derive-state-db-open.test.ts
new file mode 100644
index 000000000..5c2d18cfc
--- /dev/null
+++ b/src/resources/extensions/gsd/tests/bootstrap-derive-state-db-open.test.ts
@@ -0,0 +1,39 @@
+import { describe, test } from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+const systemContextSrc = readFileSync(
+  join(import.meta.dirname, "..", "bootstrap", "system-context.ts"),
+  "utf-8",
+);
+const registerHooksSrc = readFileSync(
+  join(import.meta.dirname, "..", "bootstrap", "register-hooks.ts"),
+  "utf-8",
+);
+
+describe("bootstrap deriveState DB guards (#3844)", () => {
+  test("system-context opens DB before deriveState in resume flows", () => {
+    const helperIdx = systemContextSrc.indexOf("const ensureStateDbOpen = async () => {");
+    const firstDeriveIdx = systemContextSrc.indexOf("const state = await deriveState(basePath);");
+    assert.ok(helperIdx > -1, "system-context should define a DB-open helper for deriveState callers");
+    assert.ok(firstDeriveIdx > -1, "system-context should still derive state for resume flows");
+    assert.ok(helperIdx < firstDeriveIdx, "system-context should prepare DB opening before deriveState resume calls");
+    assert.match(
+      systemContextSrc,
+      /await ensureStateDbOpen\(\);\s*\n\s*const state = await deriveState\(basePath\);/g,
+      "system-context resume flows should open DB before deriveState",
+    );
+  });
+
+  test("register-hooks opens DB before deriveState in session_before_compact", () => {
+    const compactIdx = registerHooksSrc.indexOf('pi.on("session_before_compact"');
+    assert.ok(compactIdx > -1, "register-hooks should define session_before_compact");
+    const compactSection = registerHooksSrc.slice(compactIdx, compactIdx + 1600);
+    const ensureIdx = compactSection.indexOf("ensureDbOpen()");
+    const deriveIdx = compactSection.indexOf("deriveState(basePath)");
+    assert.ok(ensureIdx > -1, "session_before_compact should call ensureDbOpen()");
+    assert.ok(deriveIdx > -1, "session_before_compact should derive state");
+    assert.ok(ensureIdx < deriveIdx, "session_before_compact should open DB before deriveState");
+  });
+});