diff --git a/hooks/hooks.json b/hooks/hooks.json
index 4c912b7..eda5fcd 100644
--- a/hooks/hooks.json
+++ b/hooks/hooks.json
@@ -12,6 +12,7 @@
     ],
     "SessionStart": [
       {
+        "matcher": "compact",
         "hooks": [
           {
             "type": "command",
diff --git a/src/hook.ts b/src/hook.ts
index 8bf7133..906c459 100644
--- a/src/hook.ts
+++ b/src/hook.ts
@@ -52,7 +52,9 @@ export async function hookPreCompact(): Promise<void> {
   if (!input.transcript_path)
     throw new Error("no transcript_path in hook input");
 
-  log(`PreCompact triggered: trigger=${input.trigger} session=${input.session_id}`);
+  log(
+    `PreCompact triggered: trigger=${input.trigger} session=${input.session_id}`,
+  );
 
   if (!(await Bun.file(input.transcript_path).exists())) {
     throw new Error(`transcript not found: ${input.transcript_path}`);
@@ -73,19 +75,29 @@ export async function hookPreCompact(): Promise<void> {
   try {
     const messages = await parseTranscript(input.transcript_path);
     const inputChars = messages.reduce((n, m) => n + m.content.length, 0);
-    log(`PreCompact: parsed ${messages.length} messages (${inputChars} chars), calling Morph API...`);
+    log(
+      `PreCompact: parsed ${messages.length} messages (${inputChars} chars), calling Morph API...`,
+    );
 
     const start = performance.now();
     const summary = await compact(messages);
     const durationMs = Math.round(performance.now() - start);
-    const ratio = inputChars > 0 ? ((summary.length / inputChars) * 100).toFixed(1) : "N/A";
+    const ratio =
+      inputChars > 0 ? ((summary.length / inputChars) * 100).toFixed(1) : "N/A";
 
-    log(`PreCompact: compaction complete in ${durationMs}ms — ${inputChars} → ${summary.length} chars (${ratio}% ratio)`);
+    log(
+      `PreCompact: compaction complete in ${durationMs}ms — ${inputChars} → ${summary.length} chars (${ratio}% ratio)`,
+    );
 
     const state: StateData = {
       summary,
       warn: input.trigger === "manual" && !input.custom_instructions,
-      stats: { messageCount: messages.length, inputChars, outputChars: summary.length, durationMs },
+      stats: {
+        messageCount: messages.length,
+        inputChars,
+        outputChars: summary.length,
+        durationMs,
+      },
     };
 
     await Bun.write(sf, JSON.stringify(state));
@@ -100,17 +112,6 @@ export async function hookPreCompact(): Promise<void> {
   }
 }
 
-function emitContext(data: string): void {
-  console.log(
-    JSON.stringify({
-      hookSpecificOutput: {
-        hookEventName: "SessionStart",
-        additionalContext: data,
-      },
-    }),
-  );
-}
-
 export async function hookSessionStart(): Promise<void> {
   const input = await readStdin<SessionStartInput>();
   if (!input.session_id) throw new Error("no session_id in hook input");
@@ -125,13 +126,17 @@ export async function hookSessionStart(): Promise<void> {
   }
 
   const state = (await file.json()) as StateData;
-  log(`SessionStart: state=${JSON.stringify({ error: state.error, warn: state.warn, summaryLen: state.summary?.length ?? 0, stats: state.stats })}`);
+  log(
+    `SessionStart: state=${JSON.stringify({ error: state.error, warn: state.warn, summaryLen: state.summary?.length ?? 0, stats: state.stats })}`,
+  );
 
   if (state.error) {
     log(`SessionStart: injecting error — ${state.error}`);
-    emitContext(
-      "ERROR: Morph compaction failed: " + state.error + "\n" +
-      "Inform the user about this error. Context from the previous conversation was NOT preserved.",
+    process.stdout.write(
+      "ERROR: Morph compaction failed: " +
+        state.error +
+        "\n" +
+        "Inform the user about this error. Context from the previous conversation was NOT preserved.",
     );
     await unlink(sf).catch(() => {});
     return;
@@ -154,12 +159,15 @@ export async function hookSessionStart(): Promise<void> {
 
   if (state.stats) {
     const { messageCount, inputChars, outputChars, durationMs } = state.stats;
-    const ratio = inputChars > 0 ? ((outputChars / inputChars) * 100).toFixed(1) : "N/A";
-    log(`SessionStart: injecting summary — ${messageCount} messages, ${inputChars} → ${outputChars} chars (${ratio}%), took ${durationMs}ms`);
+    const ratio =
+      inputChars > 0 ? ((outputChars / inputChars) * 100).toFixed(1) : "N/A";
+    log(
+      `SessionStart: injecting summary — ${messageCount} messages, ${inputChars} → ${outputChars} chars (${ratio}%), took ${durationMs}ms`,
+    );
   } else {
     log(`SessionStart: injecting summary (${data.length} chars)`);
   }
 
-  emitContext(data);
+  process.stdout.write(data);
   await unlink(sf).catch(() => {});
 }
diff --git a/src/morph.ts b/src/morph.ts
index fd4ede2..d248391 100644
--- a/src/morph.ts
+++ b/src/morph.ts
@@ -21,14 +21,14 @@ function loadApiKey(): string {
   try {
     const text = readFileSync(ENV_FILE, "utf-8");
     for (const line of text.split("\n")) {
-      const m = line.match(/^MORPH_API_KEY=(.+)$/);
-      if (m) return m[1].trim();
+      const key = line.match(/^MORPH_API_KEY=(.+)$/)?.[1];
+      if (key) return key.trim();
     }
   } catch {}
 
   throw new Error(
     "Morph API key not found. Run /morph-compact:install to configure it, " +
-    "or set MORPH_API_KEY environment variable.",
+      "or set MORPH_API_KEY environment variable.",
   );
 }