From 4c2659666b0d689079128e15a299a01f6f9617ce Mon Sep 17 00:00:00 2001
From: lojasetetoco <299766123+lojasetetoco@users.noreply.github.com>
Date: Wed, 12 Aug 2026 13:53:34 -0300
Subject: [PATCH 01/11] fix(hooks): update cost-tracker pricing table and
 filter harness noise from session summaries

cost-tracker.js: RATE_TABLE priced all Opus models at the legacy $15/$75
tier and routed Fable/Mythos 5 to Sonnet rates, overstating Opus 5
sessions ~3x and understating Fable ~3.3x in costs.jsonl. Adds fable
($10/$50) and current opus ($5/$25) tiers, keeps Opus 4.0/4.1/3 on the
legacy tier, updates haiku to 4.5 pricing ($1/$5).

session-end.js: extractSessionSummary included local-command echoes
(<local-command-caveat>, <command-name>, <local-command-stdout>),
system reminders, tool_result carrier turns and isMeta entries in the
Tasks list, so SessionStart reloaded noise instead of user asks. Adds
a noise filter.

Both test suites pass (10/10 cost-tracker, 1/1 session-end).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 scripts/hooks/cost-tracker.js | 13 ++++++++++---
 scripts/hooks/session-end.js  |  6 +++++-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/scripts/hooks/cost-tracker.js b/scripts/hooks/cost-tracker.js
index 3de1eaaec..fa3677e4f 100755
--- a/scripts/hooks/cost-tracker.js
+++ b/scripts/hooks/cost-tracker.js
@@ -70,15 +70,22 @@ function readHarnessCost(sessionId, maxAgeSeconds) {
 
 // Approximate per-1M-token billing rates (USD).
 // Cache creation: 1.25x input rate. Cache read: 0.1x input rate.
+// Current-generation list prices: Fable/Mythos 5 $10/$50, Opus 5 and
+// Opus 4.5-4.8 $5/$25, Sonnet 5/4.6 $3/$15, Haiku 4.5 $1/$5. Opus 4.0/4.1
+// and Opus 3 stay on the legacy $15/$75 tier.
 const RATE_TABLE = {
-  haiku:  { in: 0.80,  out: 4.0,  cacheWrite: 1.00,  cacheRead: 0.08 },
-  sonnet: { in: 3.00,  out: 15.0, cacheWrite: 3.75,  cacheRead: 0.30 },
-  opus:   { in: 15.00, out: 75.0, cacheWrite: 18.75, cacheRead: 1.50 }
+  haiku:      { in: 1.00,  out: 5.0,  cacheWrite: 1.25,  cacheRead: 0.10 },
+  sonnet:     { in: 3.00,  out: 15.0, cacheWrite: 3.75,  cacheRead: 0.30 },
+  opus:       { in: 5.00,  out: 25.0, cacheWrite: 6.25,  cacheRead: 0.50 },
+  opusLegacy: { in: 15.00, out: 75.0, cacheWrite: 18.75, cacheRead: 1.50 },
+  fable:      { in: 10.00, out: 50.0, cacheWrite: 12.50, cacheRead: 1.00 }
 };
 
 function getRates(model) {
   const m = String(model || '').toLowerCase();
+  if (m.includes('fable') || m.includes('mythos')) return RATE_TABLE.fable;
   if (m.includes('haiku')) return RATE_TABLE.haiku;
+  if (m.includes('opus-4-1') || m.includes('opus-4-0') || m.includes('3-opus')) return RATE_TABLE.opusLegacy;
   if (m.includes('opus'))  return RATE_TABLE.opus;
   return RATE_TABLE.sonnet;
 }
diff --git a/scripts/hooks/session-end.js b/scripts/hooks/session-end.js
index c224371aa..60ba74720 100644
--- a/scripts/hooks/session-end.js
+++ b/scripts/hooks/session-end.js
@@ -43,9 +43,13 @@ function extractSessionSummary(transcriptPath) {
       if (entry.type === 'user' || entry.role === 'user' || entry.message?.role === 'user') {
         // Support both direct content and nested message.content (Claude Code JSONL format)
         const rawContent = entry.message?.content ?? entry.content;
+        // Skip tool_result carrier turns — they are not user asks.
+        const isToolResult = Array.isArray(rawContent) && rawContent.some(c => c && c.type === 'tool_result');
         const text = typeof rawContent === 'string' ? rawContent : Array.isArray(rawContent) ? rawContent.map(c => (c && c.text) || '').join(' ') : '';
         const cleaned = stripAnsi(text).trim();
-        if (cleaned) {
+        // Skip harness noise: local command echoes, caveats, system reminders.
+        const isNoise = /^<(local-command-caveat|local-command-stdout|command-name|command-message|command-args|system-reminder|task-notification)/i.test(cleaned);
+        if (cleaned && !isToolResult && !isNoise && !entry.isMeta) {
           userMessages.push(cleaned.slice(0, 200));
         }
       }

From 08c1c4073cf608fe5d00d36149d9f50470322053 Mon Sep 17 00:00:00 2001
From: Amir Fathi <amirfathi.me@gmail.com>
Date: Thu, 13 Aug 2026 01:18:08 +0000
Subject: [PATCH 02/11] fix(lib): remove unused cost-estimate.js duplicate rate
 table

cost-estimate.js carries its own copy of the stale Opus/Haiku/Sonnet rate
table already reported in #2574, but grepping every .js/.json/.md file
outside node_modules turns up zero callers besides its own test. It was
added in 940135e alongside the statusline observability hooks and never
wired into any of them.

The maintainer's comment on #2656 named two acceptable outcomes: remove
the unused duplicate, or share one rate source with the live tracker.
cost-tracker.js's own fix (#2574) has not landed yet, so sharing its
table now would import numbers that are still wrong. Removing the dead
file is the smaller, immediately-correct step.

Fixes #2656
---
 scripts/lib/cost-estimate.js    |  32 ---------
 tests/lib/cost-estimate.test.js | 114 --------------------------------
 2 files changed, 146 deletions(-)
 delete mode 100644 scripts/lib/cost-estimate.js
 delete mode 100644 tests/lib/cost-estimate.test.js

diff --git a/scripts/lib/cost-estimate.js b/scripts/lib/cost-estimate.js
deleted file mode 100644
index a1651a8c9..000000000
--- a/scripts/lib/cost-estimate.js
+++ /dev/null
@@ -1,32 +0,0 @@
-'use strict';
-
-/**
- * Shared cost estimation for ECC hooks.
- *
- * Approximate per-1M-token blended rates (conservative defaults).
- */
-
-const RATE_TABLE = {
-  haiku: { in: 0.8, out: 4.0 },
-  sonnet: { in: 3.0, out: 15.0 },
-  opus: { in: 15.0, out: 75.0 }
-};
-
-/**
- * Estimate USD cost from token counts.
- * @param {string} model - Model name (may contain "haiku", "sonnet", or "opus")
- * @param {number} inputTokens
- * @param {number} outputTokens
- * @returns {number} Estimated cost in USD (rounded to 6 decimal places)
- */
-function estimateCost(model, inputTokens, outputTokens) {
-  const normalized = String(model || '').toLowerCase();
-  let rates = RATE_TABLE.sonnet;
-  if (normalized.includes('haiku')) rates = RATE_TABLE.haiku;
-  if (normalized.includes('opus')) rates = RATE_TABLE.opus;
-
-  const cost = (inputTokens / 1_000_000) * rates.in + (outputTokens / 1_000_000) * rates.out;
-  return Math.round(cost * 1e6) / 1e6;
-}
-
-module.exports = { estimateCost, RATE_TABLE };
diff --git a/tests/lib/cost-estimate.test.js b/tests/lib/cost-estimate.test.js
deleted file mode 100644
index bcb5906bc..000000000
--- a/tests/lib/cost-estimate.test.js
+++ /dev/null
@@ -1,114 +0,0 @@
-/**
- * Tests for scripts/lib/cost-estimate.js
- *
- * Run with: node tests/lib/cost-estimate.test.js
- */
-
-const assert = require('assert');
-
-const { estimateCost, RATE_TABLE } = require('../../scripts/lib/cost-estimate');
-
-// Test helper
-function test(name, fn) {
-  try {
-    fn();
-    console.log(`  \u2713 ${name}`);
-    return true;
-  } catch (err) {
-    console.log(`  \u2717 ${name}`);
-    console.log(`    Error: ${err.message}`);
-    return false;
-  }
-}
-
-function runTests() {
-  console.log('\n=== Testing cost-estimate.js ===\n');
-
-  let passed = 0;
-  let failed = 0;
-
-  // RATE_TABLE structure
-  console.log('RATE_TABLE:');
-
-  if (
-    test('RATE_TABLE has haiku, sonnet, opus keys', () => {
-      assert.ok(RATE_TABLE.haiku, 'Missing haiku');
-      assert.ok(RATE_TABLE.sonnet, 'Missing sonnet');
-      assert.ok(RATE_TABLE.opus, 'Missing opus');
-      assert.strictEqual(typeof RATE_TABLE.haiku.in, 'number');
-      assert.strictEqual(typeof RATE_TABLE.haiku.out, 'number');
-      assert.strictEqual(typeof RATE_TABLE.sonnet.in, 'number');
-      assert.strictEqual(typeof RATE_TABLE.sonnet.out, 'number');
-      assert.strictEqual(typeof RATE_TABLE.opus.in, 'number');
-      assert.strictEqual(typeof RATE_TABLE.opus.out, 'number');
-    })
-  )
-    passed++;
-  else failed++;
-
-  // estimateCost tests
-  console.log('\nestimateCost:');
-
-  if (
-    test('opus 1M/1M tokens returns 90', () => {
-      const cost = estimateCost('opus', 1_000_000, 1_000_000);
-      assert.strictEqual(cost, 90);
-    })
-  )
-    passed++;
-  else failed++;
-
-  if (
-    test('sonnet 1M/1M tokens returns 18', () => {
-      const cost = estimateCost('sonnet', 1_000_000, 1_000_000);
-      assert.strictEqual(cost, 18);
-    })
-  )
-    passed++;
-  else failed++;
-
-  if (
-    test('haiku 1M/1M tokens returns 4.8', () => {
-      const cost = estimateCost('haiku', 1_000_000, 1_000_000);
-      assert.strictEqual(cost, 4.8);
-    })
-  )
-    passed++;
-  else failed++;
-
-  if (
-    test('null model with 0 tokens returns 0', () => {
-      const cost = estimateCost(null, 0, 0);
-      assert.strictEqual(cost, 0);
-    })
-  )
-    passed++;
-  else failed++;
-
-  if (
-    test('full model name claude-opus-4-6 uses opus rates', () => {
-      const cost = estimateCost('claude-opus-4-6', 500, 200);
-      // (500 / 1_000_000) * 15 + (200 / 1_000_000) * 75 = 0.0075 + 0.015 = 0.0225
-      const expected = Math.round(0.0225 * 1e6) / 1e6;
-      assert.strictEqual(cost, expected);
-    })
-  )
-    passed++;
-  else failed++;
-
-  if (
-    test('unknown model falls back to sonnet rates', () => {
-      const cost = estimateCost('unknown-model', 1_000_000, 1_000_000);
-      assert.strictEqual(cost, 18);
-    })
-  )
-    passed++;
-  else failed++;
-
-  // Summary
-  console.log(`\nResults: ${passed} passed, ${failed} failed\n`);
-  return { passed, failed };
-}
-
-const { failed } = runTests();
-process.exit(failed > 0 ? 1 : 0);

From 08092276f9fe3cea4e7b7e5a802a0e521a78f98f Mon Sep 17 00:00:00 2001
From: Santhi Prakash <b.santhiprakash@gmail.com>
Date: Fri, 28 Aug 2026 16:22:55 -0400
Subject: [PATCH 03/11] fix(hooks): price Sonnet 5 at the published $2/$10 rate

---
 scripts/hooks/cost-tracker.js | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/scripts/hooks/cost-tracker.js b/scripts/hooks/cost-tracker.js
index fa3677e4f..e42dc97a1 100755
--- a/scripts/hooks/cost-tracker.js
+++ b/scripts/hooks/cost-tracker.js
@@ -71,11 +71,12 @@ function readHarnessCost(sessionId, maxAgeSeconds) {
 // Approximate per-1M-token billing rates (USD).
 // Cache creation: 1.25x input rate. Cache read: 0.1x input rate.
 // Current-generation list prices: Fable/Mythos 5 $10/$50, Opus 5 and
-// Opus 4.5-4.8 $5/$25, Sonnet 5/4.6 $3/$15, Haiku 4.5 $1/$5. Opus 4.0/4.1
-// and Opus 3 stay on the legacy $15/$75 tier.
+// Opus 4.5-4.8 $5/$25, Sonnet 5 $2/$10, Sonnet 4.6 $3/$15, and Haiku 4.5
+// $1/$5. Opus 4.0/4.1 and Opus 3 stay on the legacy $15/$75 tier.
 const RATE_TABLE = {
   haiku:      { in: 1.00,  out: 5.0,  cacheWrite: 1.25,  cacheRead: 0.10 },
   sonnet:     { in: 3.00,  out: 15.0, cacheWrite: 3.75,  cacheRead: 0.30 },
+  sonnet5:    { in: 2.00,  out: 10.0, cacheWrite: 2.50,  cacheRead: 0.20 },
   opus:       { in: 5.00,  out: 25.0, cacheWrite: 6.25,  cacheRead: 0.50 },
   opusLegacy: { in: 15.00, out: 75.0, cacheWrite: 18.75, cacheRead: 1.50 },
   fable:      { in: 10.00, out: 50.0, cacheWrite: 12.50, cacheRead: 1.00 }
@@ -85,11 +86,16 @@ function getRates(model) {
   const m = String(model || '').toLowerCase();
   if (m.includes('fable') || m.includes('mythos')) return RATE_TABLE.fable;
   if (m.includes('haiku')) return RATE_TABLE.haiku;
+  if (isSonnet5(m)) return RATE_TABLE.sonnet5;
   if (m.includes('opus-4-1') || m.includes('opus-4-0') || m.includes('3-opus')) return RATE_TABLE.opusLegacy;
   if (m.includes('opus'))  return RATE_TABLE.opus;
   return RATE_TABLE.sonnet;
 }
 
+function isSonnet5(model) {
+  return /(?:^|[^a-z0-9])sonnet-5(?:[^a-z0-9]|$)/.test(model);
+}
+
 function toNumber(v) {
   const n = Number(v);
   return Number.isFinite(n) ? n : 0;

From f5d0b295cb4a9d4a1197497c388e1ae2fc68bc28 Mon Sep 17 00:00:00 2001
From: Santhi Prakash <b.santhiprakash@gmail.com>
Date: Sun, 23 Aug 2026 15:45:24 +0000
Subject: [PATCH 04/11] test(hooks): expand Sonnet 5 cost-tracker coverage for
 cache and model matching

- Add cache write/read token pricing test for Sonnet 5.
- Add dated Sonnet 5 ID and claude-sonnet-50 near-miss regression tests.
- Keep Sonnet 4.6 standard rate distinction intact.

Co-Authored-By: Paperclip <noreply@paperclip.ing>
---
 tests/hooks/cost-tracker.test.js | 142 ++++++++++++++++++++++++++++++-
 1 file changed, 141 insertions(+), 1 deletion(-)

diff --git a/tests/hooks/cost-tracker.test.js b/tests/hooks/cost-tracker.test.js
index 8f652d7a1..521e7ecd2 100644
--- a/tests/hooks/cost-tracker.test.js
+++ b/tests/hooks/cost-tracker.test.js
@@ -297,7 +297,147 @@ function runTests() {
     }
   }) ? passed++ : failed++);
 
-  // 9. Ignores stale harness-cost cache and falls back to transcript estimate
+  // 9. Prices Sonnet 5 at the documented $2/$10 rate.
+  (test('prices Sonnet 5 at $12 per 1M input + 1M output tokens', () => {
+    const tmpHome = makeTempDir();
+    const transcriptPath = path.join(tmpHome, 'session.jsonl');
+    writeTranscript(transcriptPath, [
+      {
+        type: 'assistant',
+        message: {
+          id: 'msg_sonnet5',
+          model: 'claude-sonnet-5',
+          usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
+        },
+      },
+    ]);
+
+    const result = runScript(
+      { session_id: 'sonnet5-session', transcript_path: transcriptPath },
+      withTempHome(tmpHome)
+    );
+    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+
+    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+    assert.strictEqual(row.estimated_cost_usd, 12, 'Expected Sonnet 5 1M/1M to cost $12.00');
+
+    fs.rmSync(tmpHome, { recursive: true, force: true });
+  }) ? passed++ : failed++);
+
+  // 9b. Sonnet 5 cache write/read tokens use the correct rates.
+  (test('prices Sonnet 5 cache tokens at the documented rates', () => {
+    const tmpHome = makeTempDir();
+    const transcriptPath = path.join(tmpHome, 'session.jsonl');
+    writeTranscript(transcriptPath, [
+      {
+        type: 'assistant',
+        message: {
+          id: 'msg_sonnet5_cache',
+          model: 'claude-sonnet-5',
+          usage: {
+            input_tokens: 1_000_000,
+            output_tokens: 1_000_000,
+            cache_creation_input_tokens: 1_000_000,
+            cache_read_input_tokens: 1_000_000,
+          },
+        },
+      },
+    ]);
+
+    const result = runScript(
+      { session_id: 'sonnet5-cache-session', transcript_path: transcriptPath },
+      withTempHome(tmpHome)
+    );
+    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+
+    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+    assert.strictEqual(row.estimated_cost_usd, 14.7, 'Expected Sonnet 5 1M input + 1M output + 1M cache write + 1M cache read to cost $14.70');
+
+    fs.rmSync(tmpHome, { recursive: true, force: true });
+  }) ? passed++ : failed++);
+
+  // 10. Sonnet 4.6 keeps the existing $3/$15 rate and is not mistaken for Sonnet 5.
+  (test('prices Sonnet 4.6 at $18 per 1M input + 1M output tokens', () => {
+    const tmpHome = makeTempDir();
+    const transcriptPath = path.join(tmpHome, 'session.jsonl');
+    writeTranscript(transcriptPath, [
+      {
+        type: 'assistant',
+        message: {
+          id: 'msg_sonnet46',
+          model: 'claude-sonnet-4-6',
+          usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
+        },
+      },
+    ]);
+
+    const result = runScript(
+      { session_id: 'sonnet46-session', transcript_path: transcriptPath },
+      withTempHome(tmpHome)
+    );
+    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+
+    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+    assert.strictEqual(row.estimated_cost_usd, 18, 'Expected Sonnet 4.6 1M/1M to remain $18.00');
+
+    fs.rmSync(tmpHome, { recursive: true, force: true });
+  }) ? passed++ : failed++);
+
+  // 10b. Dated Sonnet 5 IDs and near-misses are matched correctly.
+  (test('prices dated Sonnet 5 IDs at $12 and rejects claude-sonnet-50 near-miss', () => {
+    const tmpHome = makeTempDir();
+    const transcriptPath = path.join(tmpHome, 'session.jsonl');
+    writeTranscript(transcriptPath, [
+      {
+        type: 'assistant',
+        message: {
+          id: 'msg_sonnet5_dated',
+          model: 'claude-sonnet-5-20261001',
+          usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
+        },
+      },
+    ]);
+
+    const result = runScript(
+      { session_id: 'sonnet5-dated-session', transcript_path: transcriptPath },
+      withTempHome(tmpHome)
+    );
+    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+
+    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+    assert.strictEqual(row.estimated_cost_usd, 12, 'Expected dated Sonnet 5 1M/1M to cost $12.00');
+
+    // Near-miss `claude-sonnet-50` must fall through to the standard Sonnet rate.
+    const nearMissPath = path.join(tmpHome, 'near-miss.jsonl');
+    writeTranscript(nearMissPath, [
+      {
+        type: 'assistant',
+        message: {
+          id: 'msg_sonnet50',
+          model: 'claude-sonnet-50',
+          usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
+        },
+      },
+    ]);
+
+    const nearResult = runScript(
+      { session_id: 'sonnet50-near-miss-session', transcript_path: nearMissPath },
+      withTempHome(tmpHome)
+    );
+    assert.strictEqual(nearResult.code, 0, `Expected exit code 0, got ${nearResult.code}`);
+
+    const lines = fs.readFileSync(metricsFile, 'utf8').trim().split('\n');
+    const nearRow = JSON.parse(lines[lines.length - 1]);
+    assert.strictEqual(nearRow.estimated_cost_usd, 18, 'Expected claude-sonnet-50 near-miss to fall back to $18.00 Sonnet rate');
+
+    fs.rmSync(tmpHome, { recursive: true, force: true });
+  }) ? passed++ : failed++);
+
+  // 11. Ignores stale harness-cost cache and falls back to transcript estimate
   (test('ignores stale harness-cost cache (>300s) and uses transcript estimate', () => {
     const tmpHome = makeTempDir();
     const sessionId = 'harness-stale-' + Date.now();

From 5ee14cb2af6a4263fa5345cd4994edc090b1447d Mon Sep 17 00:00:00 2001
From: Santhi Prakash <b.santhiprakash@gmail.com>
Date: Sun, 23 Aug 2026 15:54:00 +0000
Subject: [PATCH 05/11] test(hooks): use unique session IDs in Sonnet 5 pricing
 tests

Prevent stale /tmp/harness-cost cache files from affecting Sonnet 5, dated,
near-miss, and cache-rate pricing tests by using Date.now() in each session ID.

Co-Authored-By: Paperclip <noreply@paperclip.ing>
---
 tests/hooks/cost-tracker.test.js | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/tests/hooks/cost-tracker.test.js b/tests/hooks/cost-tracker.test.js
index 521e7ecd2..f35334663 100644
--- a/tests/hooks/cost-tracker.test.js
+++ b/tests/hooks/cost-tracker.test.js
@@ -300,6 +300,7 @@ function runTests() {
   // 9. Prices Sonnet 5 at the documented $2/$10 rate.
   (test('prices Sonnet 5 at $12 per 1M input + 1M output tokens', () => {
     const tmpHome = makeTempDir();
+    const sessionId = 'sonnet5-' + Date.now();
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -313,7 +314,7 @@ function runTests() {
     ]);
 
     const result = runScript(
-      { session_id: 'sonnet5-session', transcript_path: transcriptPath },
+      { session_id: sessionId, transcript_path: transcriptPath },
       withTempHome(tmpHome)
     );
     assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
@@ -328,6 +329,7 @@ function runTests() {
   // 9b. Sonnet 5 cache write/read tokens use the correct rates.
   (test('prices Sonnet 5 cache tokens at the documented rates', () => {
     const tmpHome = makeTempDir();
+    const sessionId = 'sonnet5-cache-' + Date.now();
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -346,7 +348,7 @@ function runTests() {
     ]);
 
     const result = runScript(
-      { session_id: 'sonnet5-cache-session', transcript_path: transcriptPath },
+      { session_id: sessionId, transcript_path: transcriptPath },
       withTempHome(tmpHome)
     );
     assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
@@ -361,6 +363,7 @@ function runTests() {
   // 10. Sonnet 4.6 keeps the existing $3/$15 rate and is not mistaken for Sonnet 5.
   (test('prices Sonnet 4.6 at $18 per 1M input + 1M output tokens', () => {
     const tmpHome = makeTempDir();
+    const sessionId = 'sonnet46-' + Date.now();
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -374,7 +377,7 @@ function runTests() {
     ]);
 
     const result = runScript(
-      { session_id: 'sonnet46-session', transcript_path: transcriptPath },
+      { session_id: sessionId, transcript_path: transcriptPath },
       withTempHome(tmpHome)
     );
     assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
@@ -389,6 +392,7 @@ function runTests() {
   // 10b. Dated Sonnet 5 IDs and near-misses are matched correctly.
   (test('prices dated Sonnet 5 IDs at $12 and rejects claude-sonnet-50 near-miss', () => {
     const tmpHome = makeTempDir();
+    const sessionId = 'sonnet5-dated-' + Date.now();
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -402,7 +406,7 @@ function runTests() {
     ]);
 
     const result = runScript(
-      { session_id: 'sonnet5-dated-session', transcript_path: transcriptPath },
+      { session_id: sessionId, transcript_path: transcriptPath },
       withTempHome(tmpHome)
     );
     assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
@@ -425,7 +429,7 @@ function runTests() {
     ]);
 
     const nearResult = runScript(
-      { session_id: 'sonnet50-near-miss-session', transcript_path: nearMissPath },
+      { session_id: 'sonnet50-near-miss-' + Date.now(), transcript_path: nearMissPath },
       withTempHome(tmpHome)
     );
     assert.strictEqual(nearResult.code, 0, `Expected exit code 0, got ${nearResult.code}`);

From 616716f370929ef891dc01a812bd8a1458c683ab Mon Sep 17 00:00:00 2001
From: Santhi Prakash <b.santhiprakash@gmail.com>
Date: Mon, 24 Aug 2026 06:10:07 +0000
Subject: [PATCH 06/11] test: isolate cost tracker cache fixtures

---
 tests/hooks/cost-tracker.test.js | 156 +++++++++++++++++++------------
 1 file changed, 95 insertions(+), 61 deletions(-)

diff --git a/tests/hooks/cost-tracker.test.js b/tests/hooks/cost-tracker.test.js
index f35334663..907bfa74a 100644
--- a/tests/hooks/cost-tracker.test.js
+++ b/tests/hooks/cost-tracker.test.js
@@ -54,6 +54,15 @@ function runScript(input, envOverrides = {}) {
   return { code: result.status || 0, stdout: result.stdout || '', stderr: result.stderr || '' };
 }
 
+function removeHarnessCostCache(sessionId) {
+  const cachePath = path.join(os.tmpdir(), `harness-cost-${sessionId}.json`);
+  try {
+    fs.unlinkSync(cachePath);
+  } catch (err) {
+    if (err.code !== 'ENOENT') throw err;
+  }
+}
+
 function runTests() {
   console.log('\n=== Testing cost-tracker.js ===\n');
 
@@ -300,7 +309,7 @@ function runTests() {
   // 9. Prices Sonnet 5 at the documented $2/$10 rate.
   (test('prices Sonnet 5 at $12 per 1M input + 1M output tokens', () => {
     const tmpHome = makeTempDir();
-    const sessionId = 'sonnet5-' + Date.now();
+    const sessionId = `sonnet5-${process.pid}-${Date.now()}`;
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -313,23 +322,33 @@ function runTests() {
       },
     ]);
 
-    const result = runScript(
-      { session_id: sessionId, transcript_path: transcriptPath },
-      withTempHome(tmpHome)
+    fs.writeFileSync(
+      path.join(os.tmpdir(), `harness-cost-${sessionId}.json`),
+      JSON.stringify({ ts: Math.floor(Date.now() / 1000), cost_usd: 999 }),
+      'utf8'
     );
-    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
 
-    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
-    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
-    assert.strictEqual(row.estimated_cost_usd, 12, 'Expected Sonnet 5 1M/1M to cost $12.00');
+    try {
+      removeHarnessCostCache(sessionId);
+      const result = runScript(
+        { session_id: sessionId, transcript_path: transcriptPath },
+        withTempHome(tmpHome)
+      );
+      assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
 
-    fs.rmSync(tmpHome, { recursive: true, force: true });
+      const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+      const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+      assert.strictEqual(row.estimated_cost_usd, 12, 'Expected Sonnet 5 1M/1M to cost $12.00');
+    } finally {
+      removeHarnessCostCache(sessionId);
+      fs.rmSync(tmpHome, { recursive: true, force: true });
+    }
   }) ? passed++ : failed++);
 
   // 9b. Sonnet 5 cache write/read tokens use the correct rates.
   (test('prices Sonnet 5 cache tokens at the documented rates', () => {
     const tmpHome = makeTempDir();
-    const sessionId = 'sonnet5-cache-' + Date.now();
+    const sessionId = `sonnet5-cache-${process.pid}-${Date.now()}`;
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -347,23 +366,27 @@ function runTests() {
       },
     ]);
 
-    const result = runScript(
-      { session_id: sessionId, transcript_path: transcriptPath },
-      withTempHome(tmpHome)
-    );
-    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+    try {
+      removeHarnessCostCache(sessionId);
+      const result = runScript(
+        { session_id: sessionId, transcript_path: transcriptPath },
+        withTempHome(tmpHome)
+      );
+      assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
 
-    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
-    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
-    assert.strictEqual(row.estimated_cost_usd, 14.7, 'Expected Sonnet 5 1M input + 1M output + 1M cache write + 1M cache read to cost $14.70');
-
-    fs.rmSync(tmpHome, { recursive: true, force: true });
+      const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+      const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+      assert.strictEqual(row.estimated_cost_usd, 14.7, 'Expected Sonnet 5 1M input + 1M output + 1M cache write + 1M cache read to cost $14.70');
+    } finally {
+      removeHarnessCostCache(sessionId);
+      fs.rmSync(tmpHome, { recursive: true, force: true });
+    }
   }) ? passed++ : failed++);
 
   // 10. Sonnet 4.6 keeps the existing $3/$15 rate and is not mistaken for Sonnet 5.
   (test('prices Sonnet 4.6 at $18 per 1M input + 1M output tokens', () => {
     const tmpHome = makeTempDir();
-    const sessionId = 'sonnet46-' + Date.now();
+    const sessionId = `sonnet46-${process.pid}-${Date.now()}`;
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -376,23 +399,28 @@ function runTests() {
       },
     ]);
 
-    const result = runScript(
-      { session_id: sessionId, transcript_path: transcriptPath },
-      withTempHome(tmpHome)
-    );
-    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+    try {
+      removeHarnessCostCache(sessionId);
+      const result = runScript(
+        { session_id: sessionId, transcript_path: transcriptPath },
+        withTempHome(tmpHome)
+      );
+      assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
 
-    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
-    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
-    assert.strictEqual(row.estimated_cost_usd, 18, 'Expected Sonnet 4.6 1M/1M to remain $18.00');
-
-    fs.rmSync(tmpHome, { recursive: true, force: true });
+      const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+      const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+      assert.strictEqual(row.estimated_cost_usd, 18, 'Expected Sonnet 4.6 1M/1M to remain $18.00');
+    } finally {
+      removeHarnessCostCache(sessionId);
+      fs.rmSync(tmpHome, { recursive: true, force: true });
+    }
   }) ? passed++ : failed++);
 
   // 10b. Dated Sonnet 5 IDs and near-misses are matched correctly.
   (test('prices dated Sonnet 5 IDs at $12 and rejects claude-sonnet-50 near-miss', () => {
     const tmpHome = makeTempDir();
-    const sessionId = 'sonnet5-dated-' + Date.now();
+    const sessionId = `sonnet5-dated-${process.pid}-${Date.now()}`;
+    const nearMissSessionId = `sonnet50-near-miss-${process.pid}-${Date.now()}`;
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -405,40 +433,46 @@ function runTests() {
       },
     ]);
 
-    const result = runScript(
-      { session_id: sessionId, transcript_path: transcriptPath },
-      withTempHome(tmpHome)
-    );
-    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+    try {
+      removeHarnessCostCache(sessionId);
+      removeHarnessCostCache(nearMissSessionId);
+      const result = runScript(
+        { session_id: sessionId, transcript_path: transcriptPath },
+        withTempHome(tmpHome)
+      );
+      assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
 
-    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
-    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
-    assert.strictEqual(row.estimated_cost_usd, 12, 'Expected dated Sonnet 5 1M/1M to cost $12.00');
+      const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+      const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+      assert.strictEqual(row.estimated_cost_usd, 12, 'Expected dated Sonnet 5 1M/1M to cost $12.00');
 
-    // Near-miss `claude-sonnet-50` must fall through to the standard Sonnet rate.
-    const nearMissPath = path.join(tmpHome, 'near-miss.jsonl');
-    writeTranscript(nearMissPath, [
-      {
-        type: 'assistant',
-        message: {
-          id: 'msg_sonnet50',
-          model: 'claude-sonnet-50',
-          usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
+      // Near-miss `claude-sonnet-50` must fall through to the standard Sonnet rate.
+      const nearMissPath = path.join(tmpHome, 'near-miss.jsonl');
+      writeTranscript(nearMissPath, [
+        {
+          type: 'assistant',
+          message: {
+            id: 'msg_sonnet50',
+            model: 'claude-sonnet-50',
+            usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
+          },
         },
-      },
-    ]);
+      ]);
 
-    const nearResult = runScript(
-      { session_id: 'sonnet50-near-miss-' + Date.now(), transcript_path: nearMissPath },
-      withTempHome(tmpHome)
-    );
-    assert.strictEqual(nearResult.code, 0, `Expected exit code 0, got ${nearResult.code}`);
+      const nearResult = runScript(
+        { session_id: nearMissSessionId, transcript_path: nearMissPath },
+        withTempHome(tmpHome)
+      );
+      assert.strictEqual(nearResult.code, 0, `Expected exit code 0, got ${nearResult.code}`);
 
-    const lines = fs.readFileSync(metricsFile, 'utf8').trim().split('\n');
-    const nearRow = JSON.parse(lines[lines.length - 1]);
-    assert.strictEqual(nearRow.estimated_cost_usd, 18, 'Expected claude-sonnet-50 near-miss to fall back to $18.00 Sonnet rate');
-
-    fs.rmSync(tmpHome, { recursive: true, force: true });
+      const lines = fs.readFileSync(metricsFile, 'utf8').trim().split('\n');
+      const nearRow = JSON.parse(lines[lines.length - 1]);
+      assert.strictEqual(nearRow.estimated_cost_usd, 18, 'Expected claude-sonnet-50 near-miss to fall back to $18.00 Sonnet rate');
+    } finally {
+      removeHarnessCostCache(sessionId);
+      removeHarnessCostCache(nearMissSessionId);
+      fs.rmSync(tmpHome, { recursive: true, force: true });
+    }
   }) ? passed++ : failed++);
 
   // 11. Ignores stale harness-cost cache and falls back to transcript estimate

From ab8cbf6505a823eed11168711678a368deeb8add Mon Sep 17 00:00:00 2001
From: Santhi Prakash <b.santhiprakash@gmail.com>
Date: Mon, 24 Aug 2026 06:41:04 +0000
Subject: [PATCH 07/11] test: cover Sonnet 5 cache rate splits

---
 tests/hooks/cost-tracker.test.js | 51 ++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/tests/hooks/cost-tracker.test.js b/tests/hooks/cost-tracker.test.js
index 907bfa74a..af6ee8671 100644
--- a/tests/hooks/cost-tracker.test.js
+++ b/tests/hooks/cost-tracker.test.js
@@ -63,6 +63,40 @@ function removeHarnessCostCache(sessionId) {
   }
 }
 
+function assertSonnet5CacheCost(cacheUsage, expectedCost, description) {
+  const tmpHome = makeTempDir();
+  const sessionId = `sonnet5-${description}-${process.pid}-${Date.now()}`;
+  const transcriptPath = path.join(tmpHome, 'session.jsonl');
+  writeTranscript(transcriptPath, [{
+    type: 'assistant',
+    message: {
+      id: `msg_sonnet5_${description}`,
+      model: 'claude-sonnet-5',
+      usage: {
+        input_tokens: 1_000_000,
+        output_tokens: 1_000_000,
+        ...cacheUsage,
+      },
+    },
+  }]);
+
+  try {
+    removeHarnessCostCache(sessionId);
+    const result = runScript(
+      { session_id: sessionId, transcript_path: transcriptPath },
+      withTempHome(tmpHome)
+    );
+    assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+
+    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+    assert.strictEqual(row.estimated_cost_usd, expectedCost, description);
+  } finally {
+    removeHarnessCostCache(sessionId);
+    fs.rmSync(tmpHome, { recursive: true, force: true });
+  }
+}
+
 function runTests() {
   console.log('\n=== Testing cost-tracker.js ===\n');
 
@@ -383,6 +417,23 @@ function runTests() {
     }
   }) ? passed++ : failed++);
 
+  // 9c. Cache write/read rates are independently covered.
+  (test('prices Sonnet 5 cache writes at $2.50 per 1M tokens', () => {
+    assertSonnet5CacheCost(
+      { cache_creation_input_tokens: 1_000_000 },
+      14.5,
+      'cache-write'
+    );
+  }) ? passed++ : failed++);
+
+  (test('prices Sonnet 5 cache reads at $0.20 per 1M tokens', () => {
+    assertSonnet5CacheCost(
+      { cache_read_input_tokens: 1_000_000 },
+      12.2,
+      'cache-read'
+    );
+  }) ? passed++ : failed++);
+
   // 10. Sonnet 4.6 keeps the existing $3/$15 rate and is not mistaken for Sonnet 5.
   (test('prices Sonnet 4.6 at $18 per 1M input + 1M output tokens', () => {
     const tmpHome = makeTempDir();

From 64f0acf60e77079ede823860953c8046bfb3b363 Mon Sep 17 00:00:00 2001
From: Santhi Prakash <b.santhiprakash@gmail.com>
Date: Mon, 24 Aug 2026 09:00:51 +0000
Subject: [PATCH 08/11] test: split Sonnet model pricing cases

---
 tests/hooks/cost-tracker.test.js | 63 ++++++++++++++++++--------------
 1 file changed, 35 insertions(+), 28 deletions(-)

diff --git a/tests/hooks/cost-tracker.test.js b/tests/hooks/cost-tracker.test.js
index af6ee8671..20054d782 100644
--- a/tests/hooks/cost-tracker.test.js
+++ b/tests/hooks/cost-tracker.test.js
@@ -467,11 +467,10 @@ function runTests() {
     }
   }) ? passed++ : failed++);
 
-  // 10b. Dated Sonnet 5 IDs and near-misses are matched correctly.
-  (test('prices dated Sonnet 5 IDs at $12 and rejects claude-sonnet-50 near-miss', () => {
+  // 10b. Dated Sonnet 5 IDs are matched correctly.
+  (test('prices dated Sonnet 5 IDs at $12', () => {
     const tmpHome = makeTempDir();
     const sessionId = `sonnet5-dated-${process.pid}-${Date.now()}`;
-    const nearMissSessionId = `sonnet50-near-miss-${process.pid}-${Date.now()}`;
     const transcriptPath = path.join(tmpHome, 'session.jsonl');
     writeTranscript(transcriptPath, [
       {
@@ -486,7 +485,6 @@ function runTests() {
 
     try {
       removeHarnessCostCache(sessionId);
-      removeHarnessCostCache(nearMissSessionId);
       const result = runScript(
         { session_id: sessionId, transcript_path: transcriptPath },
         withTempHome(tmpHome)
@@ -496,32 +494,41 @@ function runTests() {
       const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
       const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
       assert.strictEqual(row.estimated_cost_usd, 12, 'Expected dated Sonnet 5 1M/1M to cost $12.00');
-
-      // Near-miss `claude-sonnet-50` must fall through to the standard Sonnet rate.
-      const nearMissPath = path.join(tmpHome, 'near-miss.jsonl');
-      writeTranscript(nearMissPath, [
-        {
-          type: 'assistant',
-          message: {
-            id: 'msg_sonnet50',
-            model: 'claude-sonnet-50',
-            usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
-          },
-        },
-      ]);
-
-      const nearResult = runScript(
-        { session_id: nearMissSessionId, transcript_path: nearMissPath },
-        withTempHome(tmpHome)
-      );
-      assert.strictEqual(nearResult.code, 0, `Expected exit code 0, got ${nearResult.code}`);
-
-      const lines = fs.readFileSync(metricsFile, 'utf8').trim().split('\n');
-      const nearRow = JSON.parse(lines[lines.length - 1]);
-      assert.strictEqual(nearRow.estimated_cost_usd, 18, 'Expected claude-sonnet-50 near-miss to fall back to $18.00 Sonnet rate');
     } finally {
       removeHarnessCostCache(sessionId);
-      removeHarnessCostCache(nearMissSessionId);
+      fs.rmSync(tmpHome, { recursive: true, force: true });
+    }
+  }) ? passed++ : failed++);
+
+  // 10c. Near-miss Sonnet 5 IDs fall back to standard Sonnet rates.
+  (test('rejects claude-sonnet-50 as a Sonnet 5 near-miss', () => {
+    const tmpHome = makeTempDir();
+    const sessionId = `sonnet50-near-miss-${process.pid}-${Date.now()}`;
+    const transcriptPath = path.join(tmpHome, 'session.jsonl');
+    writeTranscript(transcriptPath, [
+      {
+        type: 'assistant',
+        message: {
+          id: 'msg_sonnet50',
+          model: 'claude-sonnet-50',
+          usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
+        },
+      },
+    ]);
+
+    try {
+      removeHarnessCostCache(sessionId);
+      const result = runScript(
+        { session_id: sessionId, transcript_path: transcriptPath },
+        withTempHome(tmpHome)
+      );
+      assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+
+      const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+      const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+      assert.strictEqual(row.estimated_cost_usd, 18, 'Expected claude-sonnet-50 near-miss to fall back to $18.00 Sonnet rate');
+    } finally {
+      removeHarnessCostCache(sessionId);
       fs.rmSync(tmpHome, { recursive: true, force: true });
     }
   }) ? passed++ : failed++);

From 77c358dd3fbf7a5e67cbb93b469fe3de110cc0db Mon Sep 17 00:00:00 2001
From: haelyra <49814733+haelyra@users.noreply.github.com>
Date: Fri, 28 Aug 2026 16:26:13 -0400
Subject: [PATCH 09/11] fix(costs): retain dated Opus 4 legacy pricing

---
 scripts/hooks/cost-tracker.js    |  6 ++++-
 tests/hooks/cost-tracker.test.js | 45 ++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/scripts/hooks/cost-tracker.js b/scripts/hooks/cost-tracker.js
index e42dc97a1..9f8b07e87 100755
--- a/scripts/hooks/cost-tracker.js
+++ b/scripts/hooks/cost-tracker.js
@@ -82,12 +82,16 @@ const RATE_TABLE = {
   fable:      { in: 10.00, out: 50.0, cacheWrite: 12.50, cacheRead: 1.00 }
 };
 
+// Opus 4.0's dated snapshot omits the minor segment, so an `opus-4-0`
+// substring check alone misses `claude-opus-4-20250514`.
+const LEGACY_OPUS_RE = /3-opus|opus-4-0(?!\d)|opus-4-1(?!\d)|opus-4[-@]\d{8}/;
+
 function getRates(model) {
   const m = String(model || '').toLowerCase();
   if (m.includes('fable') || m.includes('mythos')) return RATE_TABLE.fable;
   if (m.includes('haiku')) return RATE_TABLE.haiku;
   if (isSonnet5(m)) return RATE_TABLE.sonnet5;
-  if (m.includes('opus-4-1') || m.includes('opus-4-0') || m.includes('3-opus')) return RATE_TABLE.opusLegacy;
+  if (LEGACY_OPUS_RE.test(m)) return RATE_TABLE.opusLegacy;
   if (m.includes('opus'))  return RATE_TABLE.opus;
   return RATE_TABLE.sonnet;
 }
diff --git a/tests/hooks/cost-tracker.test.js b/tests/hooks/cost-tracker.test.js
index 20054d782..78e72f68c 100644
--- a/tests/hooks/cost-tracker.test.js
+++ b/tests/hooks/cost-tracker.test.js
@@ -533,6 +533,51 @@ function runTests() {
     }
   }) ? passed++ : failed++);
 
+  // 10d. Opus 4.0's dated ID has no explicit minor segment. It must retain
+  // the legacy $15/$75 rate while Opus 4.5 uses the current $5/$25 rate.
+  (test('distinguishes the dated Opus 4.0 snapshot from current Opus 4.x', () => {
+    const priceModel = model => {
+      const tmpHome = makeTempDir();
+      const sessionId = `opus-rate-${process.pid}-${Date.now()}-${model}`;
+      const transcriptPath = path.join(tmpHome, 'session.jsonl');
+      writeTranscript(transcriptPath, [
+        {
+          type: 'assistant',
+          message: {
+            id: `msg_${model}`,
+            model,
+            usage: { input_tokens: 1_000_000, output_tokens: 1_000_000 },
+          },
+        },
+      ]);
+
+      try {
+        removeHarnessCostCache(sessionId);
+        const result = runScript(
+          { session_id: sessionId, transcript_path: transcriptPath },
+          withTempHome(tmpHome)
+        );
+        assert.strictEqual(result.code, 0, `Expected exit code 0, got ${result.code}`);
+        const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'costs.jsonl');
+        return JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim()).estimated_cost_usd;
+      } finally {
+        removeHarnessCostCache(sessionId);
+        fs.rmSync(tmpHome, { recursive: true, force: true });
+      }
+    };
+
+    assert.strictEqual(
+      priceModel('claude-opus-4-20250514'),
+      90,
+      'Expected dated Opus 4.0 to retain the legacy $15/$75 rate'
+    );
+    assert.strictEqual(
+      priceModel('claude-opus-4-5-20251101'),
+      30,
+      'Expected Opus 4.5 to use the current $5/$25 rate'
+    );
+  }) ? passed++ : failed++);
+
   // 11. Ignores stale harness-cost cache and falls back to transcript estimate
   (test('ignores stale harness-cost cache (>300s) and uses transcript estimate', () => {
     const tmpHome = makeTempDir();

From 1d19789c7576ce5e43d53bb156bf2be67751b941 Mon Sep 17 00:00:00 2001
From: haelyra <49814733+haelyra@users.noreply.github.com>
Date: Fri, 28 Aug 2026 16:28:12 -0400
Subject: [PATCH 10/11] fix(hooks): preserve metadata-marked human prompts

---
 scripts/hooks/session-end.js |  5 ++++-
 tests/hooks/hooks.test.js    | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/scripts/hooks/session-end.js b/scripts/hooks/session-end.js
index 60ba74720..cb4ba7ac1 100644
--- a/scripts/hooks/session-end.js
+++ b/scripts/hooks/session-end.js
@@ -49,7 +49,10 @@ function extractSessionSummary(transcriptPath) {
         const cleaned = stripAnsi(text).trim();
         // Skip harness noise: local command echoes, caveats, system reminders.
         const isNoise = /^<(local-command-caveat|local-command-stdout|command-name|command-message|command-args|system-reminder|task-notification)/i.test(cleaned);
-        if (cleaned && !isToolResult && !isNoise && !entry.isMeta) {
+        // `isMeta` is also used for genuine channel- and plugin-originated
+        // human prompts. Exclude known structured noise above instead of
+        // discarding every metadata-marked user turn.
+        if (cleaned && !isToolResult && !isNoise) {
           userMessages.push(cleaned.slice(0, 200));
         }
       }
diff --git a/tests/hooks/hooks.test.js b/tests/hooks/hooks.test.js
index 49d6f1e23..7a5a4e7c3 100644
--- a/tests/hooks/hooks.test.js
+++ b/tests/hooks/hooks.test.js
@@ -2118,6 +2118,41 @@ async function runTests() {
     passed++;
   else failed++;
 
+  if (
+    await asyncTest('keeps isMeta human prompts while filtering structured transcript noise', async () => {
+      const testDir = createTestDir();
+      const transcriptPath = path.join(testDir, 'transcript.jsonl');
+      const lines = [
+        JSON.stringify({ type: 'user', isMeta: true, content: 'Prompt delivered by a channel plugin' }),
+        JSON.stringify({ type: 'user', isMeta: true, content: '<system-reminder>internal harness context</system-reminder>' }),
+        JSON.stringify({
+          type: 'user',
+          message: { role: 'user', content: [{ type: 'tool_result', content: 'tool output' }] },
+        }),
+      ];
+      fs.writeFileSync(transcriptPath, lines.join('\n'));
+
+      const result = await runScript(
+        path.join(scriptsDir, 'session-end.js'),
+        JSON.stringify({ transcript_path: transcriptPath }),
+        { HOME: testDir, USERPROFILE: testDir }
+      );
+      assert.strictEqual(result.code, 0);
+
+      const sessionsDir = getCanonicalSessionsDir(testDir);
+      const sessionFiles = fs.readdirSync(sessionsDir).filter(file => file.endsWith('.tmp'));
+      assert.strictEqual(sessionFiles.length, 1, 'Should create one session file');
+      const content = fs.readFileSync(path.join(sessionsDir, sessionFiles[0]), 'utf8');
+      assert.ok(content.includes('Prompt delivered by a channel plugin'));
+      assert.ok(!content.includes('internal harness context'));
+      assert.ok(!content.includes('tool output'));
+      assert.ok(content.includes('Total user messages: 1'));
+      cleanupTestDir(testDir);
+    })
+  )
+    passed++;
+  else failed++;
+
   if (
     await asyncTest('extracts tool names and file paths from transcript', async () => {
       const testDir = createTestDir();

From e51224697d4be22ac88458deb16d275f52d76276 Mon Sep 17 00:00:00 2001
From: haelyra <49814733+haelyra@users.noreply.github.com>
Date: Fri, 28 Aug 2026 16:38:56 -0400
Subject: [PATCH 11/11] docs(costs): cite the pricing contract

---
 scripts/hooks/cost-tracker.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scripts/hooks/cost-tracker.js b/scripts/hooks/cost-tracker.js
index 9f8b07e87..981f67619 100755
--- a/scripts/hooks/cost-tracker.js
+++ b/scripts/hooks/cost-tracker.js
@@ -70,6 +70,7 @@ function readHarnessCost(sessionId, maxAgeSeconds) {
 
 // Approximate per-1M-token billing rates (USD).
 // Cache creation: 1.25x input rate. Cache read: 0.1x input rate.
+// Source: https://platform.claude.com/docs/en/about-claude/pricing
 // Current-generation list prices: Fable/Mythos 5 $10/$50, Opus 5 and
 // Opus 4.5-4.8 $5/$25, Sonnet 5 $2/$10, Sonnet 4.6 $3/$15, and Haiku 4.5
 // $1/$5. Opus 4.0/4.1 and Opus 3 stay on the legacy $15/$75 tier.