From b3268fef801814340dbd9307dda792bff79efbda Mon Sep 17 00:00:00 2001
From: Affaan Mustafa <me@affaanmustafa.com>
Date: Thu, 18 Jun 2026 16:49:58 -0400
Subject: [PATCH] fix: resolve four bug reports (#2290, #2282, #2276, #2272)
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- #2290 suggest-compact: honor ECC_CONTEXT_WINDOW_TOKENS / CLAUDE_CODE_AUTO_COMPACT_WINDOW
  so 400k-window models (Opus 4.x) no longer report ~double context usage; add
  override + isolation tests in transcript-context.test.js.
- #2282 install: bare-language syntax is legacy-only by design, but the error
  now distinguishes a supported-but-wrong-mode target (gemini/codex/…) from a
  genuinely unknown one and points to --profile/--modules/--skills.
- #2276 cost-report: the command + cost-tracking skill targeted a SQLite DB no
  tracker writes. Repoint both at the real ~/.claude/metrics/costs.jsonl (JSONL,
  estimated_cost_usd), reduce cumulative-per-session snapshots to latest-per-session,
  and use node instead of sqlite3 for cross-platform support.
- #2272 gateguard: make the 'confirm no existing file' checklist item
  tool-agnostic (Glob/Grep or find/grep via Bash) so hosts without a Glob tool
  don't get a dead tool call.

Full suite 2839/2839; lint green.
---
 commands/cost-report.md               | 148 ++++++-------
 docs/COMMAND-REGISTRY.json            |   2 +-
 scripts/hooks/gateguard-fact-force.js |  51 ++---
 scripts/lib/install-executor.js       | 286 ++++++++++++--------------
 scripts/lib/transcript-context.js     |  29 ++-
 skills/cost-tracking/SKILL.md         | 165 +++++----------
 tests/lib/transcript-context.test.js  |  68 +++---
 7 files changed, 325 insertions(+), 424 deletions(-)

diff --git a/commands/cost-report.md b/commands/cost-report.md
index adf2d252..f482b593 100644
--- a/commands/cost-report.md
+++ b/commands/cost-report.md
@@ -1,107 +1,81 @@
 ---
-description: Generate a local Claude Code cost report from a cost-tracker SQLite database.
+description: Generate a local Claude Code cost report from the ECC cost-tracker metrics log.
 argument-hint: [csv]
 ---
 
 # Cost Report
 
-Query the local cost-tracking database and present a spending report by day,
-project, tool, and session. This command assumes a cost-tracking hook or plugin
-is already writing usage rows to `~/.claude-cost-tracker/usage.db`.
+Summarize local Claude Code spend by day, model, and session from the metrics
+log that ECC's `stop:cost-tracker` hook writes.
 
-## What This Command Does
+## Where the data lives
 
-1. Check that `sqlite3` is available.
-2. Check that `~/.claude-cost-tracker/usage.db` exists.
-3. Run aggregate queries against the `usage` table.
-4. Present a compact report, or export recent rows as CSV when the argument is
-   `csv`.
+The tracker appends one JSON object per session-stop to
+`~/.claude/metrics/costs.jsonl`. Each row is a **cumulative snapshot for that
+session**, so the report takes the **latest row per `session_id`** and sums
+across sessions (summing every row would multiply-count).
 
-## Prerequisites
+Row schema:
+`{ timestamp, session_id, transcript_path, model, input_tokens, output_tokens, cache_write_tokens, cache_read_tokens, estimated_cost_usd }`
 
-The database must be populated by a local cost tracker. If the file is missing,
-tell the user the tracker is not set up and suggest installing or enabling a
-trusted Claude Code cost-tracking hook/plugin first.
+## What this command does
+
+1. Check that `~/.claude/metrics/costs.jsonl` exists. If it does not, tell the
+   user the tracker is not set up yet (it populates after the first session ends
+   with the `stop:cost-tracker` hook enabled).
+2. Reduce rows to the latest snapshot per session and aggregate.
+3. Present a compact report, or export recent rows as CSV when the argument is `csv`.
+
+`node` is used instead of `sqlite3`/`jq` so this works identically on macOS,
+Linux, and Windows.
+
+## Report
 
 ```bash
-test -f ~/.claude-cost-tracker/usage.db && echo "Database found" || echo "Database not found"
+node -e '
+const fs=require("fs"),os=require("os"),path=require("path");
+const f=path.join(os.homedir(),".claude","metrics","costs.jsonl");
+if(!fs.existsSync(f)){console.log("Cost tracker not set up: "+f+" not found. Enable the stop:cost-tracker hook and finish a session first.");process.exit(0);}
+const rows=fs.readFileSync(f,"utf8").split(/\r?\n/).filter(Boolean).map(l=>{try{return JSON.parse(l)}catch{return null}}).filter(Boolean);
+const bySession=new Map();
+for(const r of rows){const k=r.session_id||r.transcript_path||r.timestamp;const p=bySession.get(k);if(!p||String(r.timestamp)>String(p.timestamp))bySession.set(k,r);}
+const latest=[...bySession.values()];
+const cost=r=>Number(r.estimated_cost_usd)||0;
+const day=r=>String(r.timestamp||"").slice(0,10);
+const today=new Date().toISOString().slice(0,10);
+const d=new Date(Date.now()-864e5).toISOString().slice(0,10);
+const sum=a=>a.reduce((s,r)=>s+cost(r),0);
+const f4=n=>"$"+n.toFixed(4);
+console.log("=== Cost summary ===");
+console.log("today:     "+f4(sum(latest.filter(r=>day(r)===today))));
+console.log("yesterday: "+f4(sum(latest.filter(r=>day(r)===d))));
+console.log("total:     "+f4(sum(latest))+"  ("+latest.length+" sessions)");
+const by=(key)=>{const m=new Map();for(const r of latest){const k=key(r)||"(unknown)";m.set(k,(m.get(k)||0)+cost(r));}return [...m.entries()].sort((a,b)=>b[1]-a[1]);};
+console.log("\n=== By model ===");for(const [k,v] of by(r=>r.model))console.log(f4(v).padStart(12)+"  "+k);
+console.log("\n=== Last 7 days ===");
+const days=new Map();for(const r of latest){const k=day(r);days.set(k,(days.get(k)||0)+cost(r));}
+[...days.entries()].sort((a,b)=>b[0]<a[0]?-1:1).slice(0,7).forEach(([k,v])=>console.log(k+"  "+f4(v)));
+'
 ```
 
-## Summary Query
+## CSV export (`/cost-report csv`)
 
 ```bash
-sqlite3 -header -column ~/.claude-cost-tracker/usage.db "
-  SELECT
-    ROUND(COALESCE(SUM(CASE WHEN date(timestamp) = date('now') THEN cost_usd END), 0), 4) AS today_cost,
-    ROUND(COALESCE(SUM(CASE WHEN date(timestamp) = date('now', '-1 day') THEN cost_usd END), 0), 4) AS yesterday_cost,
-    ROUND(COALESCE(SUM(cost_usd), 0), 4) AS total_cost,
-    COUNT(*) AS total_calls,
-    COUNT(DISTINCT session_id) AS sessions
-  FROM usage;
-"
+node -e '
+const fs=require("fs"),os=require("os"),path=require("path");
+const f=path.join(os.homedir(),".claude","metrics","costs.jsonl");
+if(!fs.existsSync(f)){console.error("no data");process.exit(0);}
+const rows=fs.readFileSync(f,"utf8").split(/\r?\n/).filter(Boolean).map(l=>{try{return JSON.parse(l)}catch{return null}}).filter(Boolean).slice(-100);
+console.log("timestamp,session_id,model,input_tokens,output_tokens,cache_write_tokens,cache_read_tokens,estimated_cost_usd");
+for(const r of rows)console.log([r.timestamp,r.session_id,r.model,r.input_tokens,r.output_tokens,r.cache_write_tokens,r.cache_read_tokens,r.estimated_cost_usd].join(","));
+'
 ```
 
-## Project Breakdown
+## Report format
 
-```bash
-sqlite3 -header -column ~/.claude-cost-tracker/usage.db "
-  SELECT project, ROUND(SUM(cost_usd), 4) AS cost, COUNT(*) AS calls
-  FROM usage
-  GROUP BY project
-  ORDER BY cost DESC;
-"
-```
+1. Summary: today, yesterday, total, session count.
+2. By model: models ranked by total cost.
+3. Last seven days: date and cost.
 
-## Tool Breakdown
-
-```bash
-sqlite3 -header -column ~/.claude-cost-tracker/usage.db "
-  SELECT tool_name, ROUND(SUM(cost_usd), 4) AS cost, COUNT(*) AS calls
-  FROM usage
-  GROUP BY tool_name
-  ORDER BY cost DESC;
-"
-```
-
-## Last Seven Days
-
-```bash
-sqlite3 -header -column ~/.claude-cost-tracker/usage.db "
-  SELECT date(timestamp) AS date, ROUND(SUM(cost_usd), 4) AS cost, COUNT(*) AS calls
-  FROM usage
-  GROUP BY date(timestamp)
-  ORDER BY date DESC
-  LIMIT 7;
-"
-```
-
-## CSV Export
-
-If the user asks for `/cost-report csv`, export the most recent usage rows with
-an explicit column list:
-
-```bash
-sqlite3 -csv -header ~/.claude-cost-tracker/usage.db "
-  SELECT timestamp, project, tool_name, input_tokens, output_tokens, cost_usd, session_id, model
-  FROM usage
-  ORDER BY timestamp DESC
-  LIMIT 100;
-"
-```
-
-## Report Format
-
-Format the response as:
-
-1. Summary: today, yesterday, total, calls, sessions.
-2. By project: projects ranked by total cost.
-3. By tool: tools ranked by total cost.
-4. Last seven days: date, cost, call count.
-
-Use four decimal places for sub-dollar amounts. Do not estimate pricing from raw
-tokens in this command; rely on the precomputed `cost_usd` values written by the
-tracker.
-
-## Source
-
-Salvaged from stale community PR #1304 by `MayurBhavsar`.
+Rely on the precomputed `estimated_cost_usd` values written by the tracker; do
+not re-estimate pricing from raw tokens here.
diff --git a/docs/COMMAND-REGISTRY.json b/docs/COMMAND-REGISTRY.json
index 056287b4..ace19851 100644
--- a/docs/COMMAND-REGISTRY.json
+++ b/docs/COMMAND-REGISTRY.json
@@ -49,7 +49,7 @@
     },
     {
       "command": "cost-report",
-      "description": "Generate a local Claude Code cost report from a cost-tracker SQLite database.",
+      "description": "Generate a local Claude Code cost report from the ECC cost-tracker metrics log.",
       "type": "testing",
       "primaryAgents": [],
       "allAgents": [],
diff --git a/scripts/hooks/gateguard-fact-force.js b/scripts/hooks/gateguard-fact-force.js
index 19d8b01a..ccfd8f44 100644
--- a/scripts/hooks/gateguard-fact-force.js
+++ b/scripts/hooks/gateguard-fact-force.js
@@ -25,11 +25,7 @@
 const crypto = require('crypto');
 const fs = require('fs');
 const path = require('path');
-const {
-  extractCommandSubstitutions,
-  extractSubshellGroups,
-  extractBraceGroups
-} = require('../lib/shell-substitution');
+const { extractCommandSubstitutions, extractSubshellGroups, extractBraceGroups } = require('../lib/shell-substitution');
 
 // Session state — scoped per session to avoid cross-session races.
 const STATE_DIR = process.env.GATEGUARD_STATE_DIR || path.join(process.env.HOME || process.env.USERPROFILE || '/tmp', '.gateguard');
@@ -88,10 +84,10 @@ function getExtraDestructiveRegex() {
     extraDestructiveCacheRegex = null;
     if (!extraDestructiveWarnLogged) {
       try {
-        process.stderr.write(
-          `[gateguard-fact-force] ignoring invalid GATEGUARD_BASH_EXTRA_DESTRUCTIVE regex: ${err.message}\n`
-        );
-      } catch (_) { /* stderr write failure is non-fatal */ }
+        process.stderr.write(`[gateguard-fact-force] ignoring invalid GATEGUARD_BASH_EXTRA_DESTRUCTIVE regex: ${err.message}\n`);
+      } catch (_) {
+        /* stderr write failure is non-fatal */
+      }
       extraDestructiveWarnLogged = true;
     }
   }
@@ -112,9 +108,7 @@ function isRoutineBashGateDisabled() {
  * @returns {string}
  */
 function stripQuotedStrings(input) {
-  return input
-    .replace(/'(?:[^'\\]|\\.)*'/g, "''")
-    .replace(/"(?:[^"\\]|\\.)*"/g, '""');
+  return input.replace(/'(?:[^'\\]|\\.)*'/g, "''").replace(/"(?:[^"\\]|\\.)*"/g, '""');
 }
 
 /**
@@ -168,7 +162,6 @@ function tokenize(segment) {
   return segment.split(/\s+/).filter(Boolean);
 }
 
-
 /**
  * Tokenize a short allowlisted shell command while preserving quoted
  * arguments. This is intentionally smaller than a full shell parser: the
@@ -236,7 +229,10 @@ function tokenizeAllowlistedShellWords(input) {
  */
 function commandBasename(token) {
   if (!token) return '';
-  return token.replace(/^.*[\\/]/, '').replace(/\.exe$/i, '').toLowerCase();
+  return token
+    .replace(/^.*[\\/]/, '')
+    .replace(/\.exe$/i, '')
+    .toLowerCase();
 }
 
 /**
@@ -553,7 +549,10 @@ function isDestructiveBash(command) {
   // that false-negative while also catching `&&`, `;`, `|`, and `||` compound forms.
   const bodies = collectExecutableBodies(raw);
   for (const body of bodies) {
-    for (const rawSeg of body.split(/[;|&]+/).map(s => s.trim()).filter(Boolean)) {
+    for (const rawSeg of body
+      .split(/[;|&]+/)
+      .map(s => s.trim())
+      .filter(Boolean)) {
       if (isDestructiveFindExec(rawSeg)) return true;
     }
   }
@@ -573,7 +572,9 @@ function isDestructiveBash(command) {
 // --- State management (per-session, atomic writes, bounded) ---
 
 function normalizeEnvValue(value) {
-  return String(value || '').trim().toLowerCase();
+  return String(value || '')
+    .trim()
+    .toLowerCase();
 }
 
 function isGateGuardDisabled() {
@@ -886,8 +887,7 @@ function isReadOnlyGitIntrospection(command) {
     if (args.length === 2) {
       const [first, second] = args;
       // ref + flag
-      if (!first.startsWith('--') && /^[a-zA-Z0-9._:/ -]+$/.test(first) &&
-          (second === '--stat' || second === '--name-only')) {
+      if (!first.startsWith('--') && /^[a-zA-Z0-9._:/ -]+$/.test(first) && (second === '--stat' || second === '--name-only')) {
         return true;
       }
       return false;
@@ -932,7 +932,7 @@ function writeGateMsg(filePath) {
     `Before creating ${safe}, present these facts:`,
     '',
     '1. Name the file(s) and line(s) that will call this new file',
-    '2. Confirm no existing file serves the same purpose (use Glob)',
+    '2. Confirm no existing file serves the same purpose (search the tree — Glob/Grep, or find/grep via Bash)',
     '3. If this file reads/writes data files, show field names, structure, and date format (use redacted or synthetic values, not raw production data)',
     "4. Quote the user's current instruction verbatim",
     '',
@@ -983,11 +983,7 @@ function routineBashMsg() {
 
 function withRecoveryHint(message, hookIds = [EDIT_WRITE_HOOK_ID]) {
   const disableTargets = hookIds.map(hookId => `\`${hookId}\``).join(' or ');
-  return [
-    message,
-    '',
-    `Recovery: if GateGuard is blocking setup or repair work, run this session with \`ECC_GATEGUARD=off\` or add ${disableTargets} to \`ECC_DISABLED_HOOKS\`.`
-  ].join('\n');
+  return [message, '', `Recovery: if GateGuard is blocking setup or repair work, run this session with \`ECC_GATEGUARD=off\` or add ${disableTargets} to \`ECC_DISABLED_HOOKS\`.`].join('\n');
 }
 
 function isSubagentInvocation(data) {
@@ -995,12 +991,7 @@ function isSubagentInvocation(data) {
     return false;
   }
 
-  const candidates = [
-    data.agent_id,
-    data.agentId,
-    data.parent_tool_use_id,
-    data.parentToolUseId
-  ];
+  const candidates = [data.agent_id, data.agentId, data.parent_tool_use_id, data.parentToolUseId];
 
   return candidates.some(candidate => typeof candidate === 'string' && candidate.trim());
 }
diff --git a/scripts/lib/install-executor.js b/scripts/lib/install-executor.js
index ce2274ea..e5855ecc 100644
--- a/scripts/lib/install-executor.js
+++ b/scripts/lib/install-executor.js
@@ -5,20 +5,12 @@ const { execFileSync } = require('child_process');
 
 const { toCursorAgentRelativePath } = require('./cursor-agent-names');
 const { LEGACY_INSTALL_TARGETS, parseInstallArgs } = require('./install/request');
-const {
-  SUPPORTED_INSTALL_TARGETS,
-  listLegacyCompatibilityLanguages,
-  resolveLegacyCompatibilitySelection,
-  resolveInstallPlan,
-} = require('./install-manifests');
+const { SUPPORTED_INSTALL_TARGETS, listLegacyCompatibilityLanguages, resolveLegacyCompatibilitySelection, resolveInstallPlan } = require('./install-manifests');
 const { getInstallTargetAdapter } = require('./install-targets/registry');
 
 const LANGUAGE_NAME_PATTERN = /^[a-zA-Z0-9_-]+$/;
 const CLAUDE_ECC_NAMESPACE = 'ecc';
-const EXCLUDED_GENERATED_SOURCE_SUFFIXES = [
-  '/ecc-install-state.json',
-  '/ecc/install-state.json',
-];
+const EXCLUDED_GENERATED_SOURCE_SUFFIXES = ['/ecc-install-state.json', '/ecc/install-state.json'];
 
 function getSourceRoot() {
   return path.join(__dirname, '../..');
@@ -26,9 +18,7 @@ function getSourceRoot() {
 
 function getPackageVersion(sourceRoot) {
   try {
-    const packageJson = JSON.parse(
-      fs.readFileSync(path.join(sourceRoot, 'package.json'), 'utf8')
-    );
+    const packageJson = JSON.parse(fs.readFileSync(path.join(sourceRoot, 'package.json'), 'utf8'));
     return packageJson.version || null;
   } catch (_error) {
     return null;
@@ -37,9 +27,7 @@ function getPackageVersion(sourceRoot) {
 
 function getManifestVersion(sourceRoot) {
   try {
-    const modulesManifest = JSON.parse(
-      fs.readFileSync(path.join(sourceRoot, 'manifests', 'install-modules.json'), 'utf8')
-    );
+    const modulesManifest = JSON.parse(fs.readFileSync(path.join(sourceRoot, 'manifests', 'install-modules.json'), 'utf8'));
     return modulesManifest.version || 1;
   } catch (_error) {
     return 1;
@@ -52,7 +40,7 @@ function getRepoCommit(sourceRoot) {
       cwd: sourceRoot,
       encoding: 'utf8',
       stdio: ['ignore', 'pipe', 'ignore'],
-      timeout: 5000,
+      timeout: 5000
     }).trim();
   } catch (_error) {
     return null;
@@ -64,32 +52,35 @@ function readDirectoryNames(dirPath) {
     return [];
   }
 
-  return fs.readdirSync(dirPath, { withFileTypes: true })
+  return fs
+    .readdirSync(dirPath, { withFileTypes: true })
     .filter(entry => entry.isDirectory())
     .map(entry => entry.name)
     .sort();
 }
 
 function listAvailableLanguages(sourceRoot = getSourceRoot()) {
-  return [...new Set([
-    ...listLegacyCompatibilityLanguages(),
-    ...readDirectoryNames(path.join(sourceRoot, 'rules'))
-      .filter(name => name !== 'common'),
-  ])].sort();
+  return [...new Set([...listLegacyCompatibilityLanguages(), ...readDirectoryNames(path.join(sourceRoot, 'rules')).filter(name => name !== 'common')])].sort();
 }
 
 function validateLegacyTarget(target) {
-  if (!LEGACY_INSTALL_TARGETS.includes(target)) {
+  if (LEGACY_INSTALL_TARGETS.includes(target)) {
+    return;
+  }
+  // A target can be fully supported yet not installable via the bare-language
+  // positional syntax (which is legacy-only). Guide the user to the right mode
+  // instead of implying the target is unknown (#2282).
+  if (SUPPORTED_INSTALL_TARGETS.includes(target)) {
     throw new Error(
-      `Unknown install target: ${target}. Expected one of ${LEGACY_INSTALL_TARGETS.join(', ')}`
+      `Target '${target}' is supported, but the bare-language install syntax only accepts ${LEGACY_INSTALL_TARGETS.join(', ')}. ` +
+        `Install '${target}' with a component selection instead, e.g. \`install.sh --target ${target} --profile full\` ` +
+        `(or --modules <id,...> / --skills <id,...>).`
     );
   }
+  throw new Error(`Unknown install target: ${target}. Expected one of ${SUPPORTED_INSTALL_TARGETS.join(', ')}`);
 }
 
-const IGNORED_DIRECTORY_NAMES = new Set([
-  'node_modules',
-  '.git',
-]);
+const IGNORED_DIRECTORY_NAMES = new Set(['node_modules', '.git']);
 
 function listFilesRecursive(dirPath) {
   if (!fs.existsSync(dirPath)) {
@@ -141,7 +132,7 @@ function buildCopyFileOperation({ moduleId, sourcePath, sourceRelativePath, dest
     destinationPath,
     strategy,
     ownership: 'managed',
-    scaffoldOnly: false,
+    scaffoldOnly: false
   };
 }
 
@@ -156,20 +147,20 @@ function addRecursiveCopyOperations(operations, options) {
   for (const relativeFile of relativeFiles) {
     const sourceRelativePath = path.join(options.sourceRelativeDir, relativeFile);
     const sourcePath = path.join(options.sourceRoot, sourceRelativePath);
-    const destinationRelativePath = typeof options.destinationRelativePathTransform === 'function'
-      ? options.destinationRelativePathTransform(relativeFile, sourceRelativePath)
-      : relativeFile;
+    const destinationRelativePath = typeof options.destinationRelativePathTransform === 'function' ? options.destinationRelativePathTransform(relativeFile, sourceRelativePath) : relativeFile;
     if (!destinationRelativePath) {
       continue;
     }
     const destinationPath = path.join(options.destinationDir, destinationRelativePath);
-    operations.push(buildCopyFileOperation({
-      moduleId: options.moduleId,
-      sourcePath,
-      sourceRelativePath,
-      destinationPath,
-      strategy: options.strategy || 'preserve-relative-path',
-    }));
+    operations.push(
+      buildCopyFileOperation({
+        moduleId: options.moduleId,
+        sourcePath,
+        sourceRelativePath,
+        destinationPath,
+        strategy: options.strategy || 'preserve-relative-path'
+      })
+    );
   }
 
   return relativeFiles.length;
@@ -181,13 +172,15 @@ function addFileCopyOperation(operations, options) {
     return false;
   }
 
-  operations.push(buildCopyFileOperation({
-    moduleId: options.moduleId,
-    sourcePath,
-    sourceRelativePath: options.sourceRelativePath,
-    destinationPath: options.destinationPath,
-    strategy: options.strategy || 'preserve-relative-path',
-  }));
+  operations.push(
+    buildCopyFileOperation({
+      moduleId: options.moduleId,
+      sourcePath,
+      sourceRelativePath: options.sourceRelativePath,
+      destinationPath: options.destinationPath,
+      strategy: options.strategy || 'preserve-relative-path'
+    })
+  );
 
   return true;
 }
@@ -218,7 +211,7 @@ function addCursorAgentDataScaffoldOperations(operations, options) {
     sourceRoot: options.sourceRoot,
     sourceRelativePath: path.join('scaffolds', 'cursor', 'ecc-agent-data.json'),
     destinationPath: path.join(options.targetRoot, 'ecc-agent-data.json'),
-    strategy: 'preserve-relative-path',
+    strategy: 'preserve-relative-path'
   });
 
   addFileCopyOperation(operations, {
@@ -226,21 +219,17 @@ function addCursorAgentDataScaffoldOperations(operations, options) {
     sourceRoot: options.sourceRoot,
     sourceRelativePath: path.join('scaffolds', 'cursor', 'rules', 'ecc-agent-data-home.mdc'),
     destinationPath: path.join(options.targetRoot, 'rules', 'ecc-agent-data-home.mdc'),
-    strategy: 'preserve-relative-path',
+    strategy: 'preserve-relative-path'
   });
 
   addJsonMergeOperation(operations, {
     moduleId: options.moduleId,
     sourceRoot: options.sourceRoot,
     sourceRelativePath: path.join('scaffolds', 'cursor', 'hooks.json'),
-    destinationPath: path.join(options.targetRoot, 'hooks.json'),
+    destinationPath: path.join(options.targetRoot, 'hooks.json')
   });
 
-  const cursorSessionHookDeps = [
-    path.join('scripts', 'hooks', 'cursor-session-env.js'),
-    path.join('scripts', 'lib', 'agent-data-home.js'),
-    path.join('scripts', 'lib', 'utils.js'),
-  ];
+  const cursorSessionHookDeps = [path.join('scripts', 'hooks', 'cursor-session-env.js'), path.join('scripts', 'lib', 'agent-data-home.js'), path.join('scripts', 'lib', 'utils.js')];
 
   for (const sourceRelativePath of cursorSessionHookDeps) {
     addFileCopyOperation(operations, {
@@ -248,7 +237,7 @@ function addCursorAgentDataScaffoldOperations(operations, options) {
       sourceRoot: options.sourceRoot,
       sourceRelativePath,
       destinationPath: path.join(options.targetRoot, sourceRelativePath),
-      strategy: 'preserve-relative-path',
+      strategy: 'preserve-relative-path'
     });
   }
 }
@@ -267,7 +256,7 @@ function addJsonMergeOperation(operations, options) {
     strategy: 'merge-json',
     ownership: 'managed',
     scaffoldOnly: false,
-    mergePayload: readJsonObject(sourcePath, options.sourceRelativePath),
+    mergePayload: readJsonObject(sourcePath, options.sourceRelativePath)
   });
 
   return true;
@@ -279,7 +268,8 @@ function addMatchingRuleOperations(operations, options) {
     return 0;
   }
 
-  const files = fs.readdirSync(sourceDir, { withFileTypes: true })
+  const files = fs
+    .readdirSync(sourceDir, { withFileTypes: true })
     .filter(entry => entry.isFile() && options.matcher(entry.name))
     .map(entry => entry.name)
     .sort();
@@ -287,18 +277,17 @@ function addMatchingRuleOperations(operations, options) {
   for (const fileName of files) {
     const sourceRelativePath = path.join(options.sourceRelativeDir, fileName);
     const sourcePath = path.join(options.sourceRoot, sourceRelativePath);
-    const destinationPath = path.join(
-      options.destinationDir,
-      options.rename ? options.rename(fileName) : fileName
-    );
+    const destinationPath = path.join(options.destinationDir, options.rename ? options.rename(fileName) : fileName);
 
-    operations.push(buildCopyFileOperation({
-      moduleId: options.moduleId,
-      sourcePath,
-      sourceRelativePath,
-      destinationPath,
-      strategy: options.strategy || 'flatten-copy',
-    }));
+    operations.push(
+      buildCopyFileOperation({
+        moduleId: options.moduleId,
+        sourcePath,
+        sourceRelativePath,
+        destinationPath,
+        strategy: options.strategy || 'flatten-copy'
+      })
+    );
   }
 
   return files.length;
@@ -324,7 +313,7 @@ function planClaudeStyleLegacyInstall(context, { adapterId, adapterRootInput, ru
     moduleId: 'legacy-claude-rules',
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: path.join('rules', 'common'),
-    destinationDir: path.join(rulesDir, 'common'),
+    destinationDir: path.join(rulesDir, 'common')
   });
 
   for (const language of context.languages) {
@@ -343,7 +332,7 @@ function planClaudeStyleLegacyInstall(context, { adapterId, adapterRootInput, ru
       moduleId: 'legacy-claude-rules',
       sourceRoot: context.sourceRoot,
       sourceRelativeDir: path.join('rules', language),
-      destinationDir: path.join(rulesDir, language),
+      destinationDir: path.join(rulesDir, language)
     });
   }
 
@@ -356,7 +345,7 @@ function planClaudeStyleLegacyInstall(context, { adapterId, adapterRootInput, ru
     installStatePath,
     operations,
     warnings,
-    selectedModules: ['legacy-claude-rules'],
+    selectedModules: ['legacy-claude-rules']
   };
 }
 
@@ -364,7 +353,7 @@ function planClaudeLegacyInstall(context) {
   return planClaudeStyleLegacyInstall(context, {
     adapterId: 'claude',
     adapterRootInput: { homeDir: context.homeDir },
-    rulesDir: context.claudeRulesDir || null,
+    rulesDir: context.claudeRulesDir || null
   });
 }
 
@@ -372,7 +361,7 @@ function planClaudeProjectLegacyInstall(context) {
   return planClaudeStyleLegacyInstall(context, {
     adapterId: 'claude-project',
     adapterRootInput: { repoRoot: context.projectRoot },
-    rulesDir: null,
+    rulesDir: null
   });
 }
 
@@ -388,14 +377,12 @@ function planCursorLegacyInstall(context) {
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: path.join('.cursor', 'rules'),
     destinationDir: path.join(targetRoot, 'rules'),
-    matcher: fileName => /^common-.*\.md$/.test(fileName),
+    matcher: fileName => /^common-.*\.md$/.test(fileName)
   });
 
   for (const language of context.languages) {
     if (!LANGUAGE_NAME_PATTERN.test(language)) {
-      warnings.push(
-        `Invalid language name '${language}'. Only alphanumeric, dash, and underscore are allowed`
-      );
+      warnings.push(`Invalid language name '${language}'. Only alphanumeric, dash, and underscore are allowed`);
       continue;
     }
 
@@ -404,7 +391,7 @@ function planCursorLegacyInstall(context) {
       sourceRoot: context.sourceRoot,
       sourceRelativeDir: path.join('.cursor', 'rules'),
       destinationDir: path.join(targetRoot, 'rules'),
-      matcher: fileName => fileName.startsWith(`${language}-`) && fileName.endsWith('.md'),
+      matcher: fileName => fileName.startsWith(`${language}-`) && fileName.endsWith('.md')
     });
 
     if (matches === 0) {
@@ -417,44 +404,44 @@ function planCursorLegacyInstall(context) {
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: path.join('.cursor', 'agents'),
     destinationDir: path.join(targetRoot, 'agents'),
-    destinationRelativePathTransform: toCursorAgentRelativePath,
+    destinationRelativePathTransform: toCursorAgentRelativePath
   });
   addRecursiveCopyOperations(operations, {
     moduleId: 'legacy-cursor-install',
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: path.join('.cursor', 'skills'),
-    destinationDir: path.join(targetRoot, 'skills'),
+    destinationDir: path.join(targetRoot, 'skills')
   });
   addRecursiveCopyOperations(operations, {
     moduleId: 'legacy-cursor-install',
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: path.join('.cursor', 'commands'),
-    destinationDir: path.join(targetRoot, 'commands'),
+    destinationDir: path.join(targetRoot, 'commands')
   });
   addRecursiveCopyOperations(operations, {
     moduleId: 'legacy-cursor-install',
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: path.join('.cursor', 'hooks'),
-    destinationDir: path.join(targetRoot, 'hooks'),
+    destinationDir: path.join(targetRoot, 'hooks')
   });
 
   addFileCopyOperation(operations, {
     moduleId: 'legacy-cursor-install',
     sourceRoot: context.sourceRoot,
     sourceRelativePath: path.join('.cursor', 'hooks.json'),
-    destinationPath: path.join(targetRoot, 'hooks.json'),
+    destinationPath: path.join(targetRoot, 'hooks.json')
   });
   addJsonMergeOperation(operations, {
     moduleId: 'legacy-cursor-install',
     sourceRoot: context.sourceRoot,
     sourceRelativePath: '.mcp.json',
-    destinationPath: path.join(targetRoot, 'mcp.json'),
+    destinationPath: path.join(targetRoot, 'mcp.json')
   });
 
   addCursorAgentDataScaffoldOperations(operations, {
     moduleId: 'legacy-cursor-install',
     sourceRoot: context.sourceRoot,
-    targetRoot,
+    targetRoot
   });
 
   return {
@@ -466,7 +453,7 @@ function planCursorLegacyInstall(context) {
     installStatePath,
     operations,
     warnings,
-    selectedModules: ['legacy-cursor-install'],
+    selectedModules: ['legacy-cursor-install']
   };
 }
 
@@ -478,9 +465,7 @@ function planAntigravityLegacyInstall(context) {
   const warnings = [];
 
   if (isDirectoryNonEmpty(path.join(targetRoot, 'rules'))) {
-    warnings.push(
-      `Destination ${path.join(targetRoot, 'rules')}/ already exists and files may be overwritten`
-    );
+    warnings.push(`Destination ${path.join(targetRoot, 'rules')}/ already exists and files may be overwritten`);
   }
 
   addMatchingRuleOperations(operations, {
@@ -489,14 +474,12 @@ function planAntigravityLegacyInstall(context) {
     sourceRelativeDir: path.join('rules', 'common'),
     destinationDir: path.join(targetRoot, 'rules'),
     matcher: fileName => fileName.endsWith('.md'),
-    rename: fileName => `common-${fileName}`,
+    rename: fileName => `common-${fileName}`
   });
 
   for (const language of context.languages) {
     if (!LANGUAGE_NAME_PATTERN.test(language)) {
-      warnings.push(
-        `Invalid language name '${language}'. Only alphanumeric, dash, and underscore are allowed`
-      );
+      warnings.push(`Invalid language name '${language}'. Only alphanumeric, dash, and underscore are allowed`);
       continue;
     }
 
@@ -512,7 +495,7 @@ function planAntigravityLegacyInstall(context) {
       sourceRelativeDir: path.join('rules', language),
       destinationDir: path.join(targetRoot, 'rules'),
       matcher: fileName => fileName.endsWith('.md'),
-      rename: fileName => `${language}-${fileName}`,
+      rename: fileName => `${language}-${fileName}`
     });
   }
 
@@ -520,19 +503,19 @@ function planAntigravityLegacyInstall(context) {
     moduleId: 'legacy-antigravity-install',
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: 'commands',
-    destinationDir: path.join(targetRoot, 'workflows'),
+    destinationDir: path.join(targetRoot, 'workflows')
   });
   addRecursiveCopyOperations(operations, {
     moduleId: 'legacy-antigravity-install',
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: 'agents',
-    destinationDir: path.join(targetRoot, 'skills'),
+    destinationDir: path.join(targetRoot, 'skills')
   });
   addRecursiveCopyOperations(operations, {
     moduleId: 'legacy-antigravity-install',
     sourceRoot: context.sourceRoot,
     sourceRelativeDir: 'skills',
-    destinationDir: path.join(targetRoot, 'skills'),
+    destinationDir: path.join(targetRoot, 'skills')
   });
 
   return {
@@ -544,7 +527,7 @@ function planAntigravityLegacyInstall(context) {
     installStatePath,
     operations,
     warnings,
-    selectedModules: ['legacy-antigravity-install'],
+    selectedModules: ['legacy-antigravity-install']
   };
 }
 
@@ -561,7 +544,7 @@ function createLegacyInstallPlan(options = {}) {
     projectRoot,
     homeDir,
     languages: Array.isArray(options.languages) ? options.languages : [],
-    claudeRulesDir: options.claudeRulesDir || process.env.CLAUDE_RULES_DIR || null,
+    claudeRulesDir: options.claudeRulesDir || process.env.CLAUDE_RULES_DIR || null
   };
 
   let plan;
@@ -578,7 +561,7 @@ function createLegacyInstallPlan(options = {}) {
   const source = {
     repoVersion: getPackageVersion(sourceRoot),
     repoCommit: getRepoCommit(sourceRoot),
-    manifestVersion: getManifestVersion(sourceRoot),
+    manifestVersion: getManifestVersion(sourceRoot)
   };
 
   const statePreview = createStatePreview({
@@ -589,14 +572,14 @@ function createLegacyInstallPlan(options = {}) {
       profile: null,
       modules: [],
       legacyLanguages: context.languages,
-      legacyMode: true,
+      legacyMode: true
     },
     resolution: {
       selectedModules: plan.selectedModules,
-      skippedModules: [],
+      skippedModules: []
     },
     operations: plan.operations,
-    source,
+    source
   });
 
   return {
@@ -605,7 +588,7 @@ function createLegacyInstallPlan(options = {}) {
     adapter: {
       id: plan.adapter.id,
       target: plan.adapter.target,
-      kind: plan.adapter.kind,
+      kind: plan.adapter.kind
     },
     targetRoot: plan.targetRoot,
     installRoot: plan.installRoot,
@@ -613,7 +596,7 @@ function createLegacyInstallPlan(options = {}) {
     warnings: plan.warnings,
     languages: context.languages,
     operations: plan.operations,
-    statePreview,
+    statePreview
   };
 }
 
@@ -621,19 +604,15 @@ function createLegacyCompatInstallPlan(options = {}) {
   const sourceRoot = options.sourceRoot || getSourceRoot();
   const projectRoot = options.projectRoot || process.cwd();
   const target = options.target || 'claude';
-  const includeComponentIds = Array.isArray(options.includeComponentIds)
-    ? [...options.includeComponentIds]
-    : [];
-  const excludeComponentIds = Array.isArray(options.excludeComponentIds)
-    ? [...options.excludeComponentIds]
-    : [];
+  const includeComponentIds = Array.isArray(options.includeComponentIds) ? [...options.includeComponentIds] : [];
+  const excludeComponentIds = Array.isArray(options.excludeComponentIds) ? [...options.excludeComponentIds] : [];
 
   validateLegacyTarget(target);
 
   const selection = resolveLegacyCompatibilitySelection({
     repoRoot: sourceRoot,
     target,
-    legacyLanguages: options.legacyLanguages || [],
+    legacyLanguages: options.legacyLanguages || []
   });
 
   return createManifestInstallPlan({
@@ -651,25 +630,24 @@ function createLegacyCompatInstallPlan(options = {}) {
     requestModuleIds: [],
     requestIncludeComponentIds: includeComponentIds,
     requestExcludeComponentIds: excludeComponentIds,
-    mode: 'legacy-compat',
+    mode: 'legacy-compat'
   });
 }
 
 function materializeScaffoldOperation(sourceRoot, operation) {
   if (operation.kind === 'merge-json') {
-    return [{
-      kind: 'merge-json',
-      moduleId: operation.moduleId,
-      sourceRelativePath: operation.sourceRelativePath,
-      destinationPath: operation.destinationPath,
-      strategy: operation.strategy || 'merge-json',
-      ownership: operation.ownership || 'managed',
-      scaffoldOnly: Object.hasOwn(operation, 'scaffoldOnly') ? operation.scaffoldOnly : false,
-      mergePayload: readJsonObject(
-        path.join(sourceRoot, operation.sourceRelativePath),
-        operation.sourceRelativePath
-      ),
-    }];
+    return [
+      {
+        kind: 'merge-json',
+        moduleId: operation.moduleId,
+        sourceRelativePath: operation.sourceRelativePath,
+        destinationPath: operation.destinationPath,
+        strategy: operation.strategy || 'merge-json',
+        ownership: operation.ownership || 'managed',
+        scaffoldOnly: Object.hasOwn(operation, 'scaffoldOnly') ? operation.scaffoldOnly : false,
+        mergePayload: readJsonObject(path.join(sourceRoot, operation.sourceRelativePath), operation.sourceRelativePath)
+      }
+    ];
   }
 
   const sourcePath = path.join(sourceRoot, operation.sourceRelativePath);
@@ -683,13 +661,15 @@ function materializeScaffoldOperation(sourceRoot, operation) {
 
   const stat = fs.statSync(sourcePath);
   if (stat.isFile()) {
-    return [buildCopyFileOperation({
-      moduleId: operation.moduleId,
-      sourcePath,
-      sourceRelativePath: operation.sourceRelativePath,
-      destinationPath: operation.destinationPath,
-      strategy: operation.strategy,
-    })];
+    return [
+      buildCopyFileOperation({
+        moduleId: operation.moduleId,
+        sourcePath,
+        sourceRelativePath: operation.sourceRelativePath,
+        destinationPath: operation.destinationPath,
+        strategy: operation.strategy
+      })
+    ];
   }
 
   const relativeFiles = listFilesRecursive(sourcePath).filter(relativeFile => {
@@ -703,7 +683,7 @@ function materializeScaffoldOperation(sourceRoot, operation) {
       sourcePath: path.join(sourcePath, relativeFile),
       sourceRelativePath,
       destinationPath: path.join(operation.destinationPath, relativeFile),
-      strategy: operation.strategy,
+      strategy: operation.strategy
     });
   });
 }
@@ -712,21 +692,19 @@ function createManifestInstallPlan(options = {}) {
   const sourceRoot = options.sourceRoot || getSourceRoot();
   const projectRoot = options.projectRoot || process.cwd();
   const target = options.target || 'claude';
-  const legacyLanguages = Array.isArray(options.legacyLanguages)
-    ? [...options.legacyLanguages]
-    : [];
-  const requestProfileId = Object.hasOwn(options, 'requestProfileId')
-    ? options.requestProfileId
-    : (options.profileId || null);
-  const requestModuleIds = Object.hasOwn(options, 'requestModuleIds')
-    ? [...options.requestModuleIds]
-    : (Array.isArray(options.moduleIds) ? [...options.moduleIds] : []);
+  const legacyLanguages = Array.isArray(options.legacyLanguages) ? [...options.legacyLanguages] : [];
+  const requestProfileId = Object.hasOwn(options, 'requestProfileId') ? options.requestProfileId : options.profileId || null;
+  const requestModuleIds = Object.hasOwn(options, 'requestModuleIds') ? [...options.requestModuleIds] : Array.isArray(options.moduleIds) ? [...options.moduleIds] : [];
   const requestIncludeComponentIds = Object.hasOwn(options, 'requestIncludeComponentIds')
     ? [...options.requestIncludeComponentIds]
-    : (Array.isArray(options.includeComponentIds) ? [...options.includeComponentIds] : []);
+    : Array.isArray(options.includeComponentIds)
+      ? [...options.includeComponentIds]
+      : [];
   const requestExcludeComponentIds = Object.hasOwn(options, 'requestExcludeComponentIds')
     ? [...options.requestExcludeComponentIds]
-    : (Array.isArray(options.excludeComponentIds) ? [...options.excludeComponentIds] : []);
+    : Array.isArray(options.excludeComponentIds)
+      ? [...options.excludeComponentIds]
+      : [];
   const plan = resolveInstallPlan({
     repoRoot: sourceRoot,
     projectRoot,
@@ -735,14 +713,14 @@ function createManifestInstallPlan(options = {}) {
     moduleIds: options.moduleIds || [],
     includeComponentIds: options.includeComponentIds || [],
     excludeComponentIds: options.excludeComponentIds || [],
-    target,
+    target
   });
   const adapter = getInstallTargetAdapter(target);
   const operations = plan.operations.flatMap(operation => materializeScaffoldOperation(sourceRoot, operation));
   const source = {
     repoVersion: getPackageVersion(sourceRoot),
     repoCommit: getRepoCommit(sourceRoot),
-    manifestVersion: getManifestVersion(sourceRoot),
+    manifestVersion: getManifestVersion(sourceRoot)
   };
   const statePreview = createStatePreview({
     adapter,
@@ -754,14 +732,14 @@ function createManifestInstallPlan(options = {}) {
       includeComponents: requestIncludeComponentIds,
       excludeComponents: requestExcludeComponentIds,
       legacyLanguages,
-      legacyMode: Boolean(options.legacyMode),
+      legacyMode: Boolean(options.legacyMode)
     },
     resolution: {
       selectedModules: plan.selectedModuleIds,
-      skippedModules: plan.skippedModuleIds,
+      skippedModules: plan.skippedModuleIds
     },
     operations,
-    source,
+    source
   });
 
   return {
@@ -770,7 +748,7 @@ function createManifestInstallPlan(options = {}) {
     adapter: {
       id: adapter.id,
       target: adapter.target,
-      kind: adapter.kind,
+      kind: adapter.kind
     },
     targetRoot: plan.targetRoot,
     installRoot: plan.targetRoot,
@@ -787,7 +765,7 @@ function createManifestInstallPlan(options = {}) {
     skippedModuleIds: plan.skippedModuleIds,
     excludedModuleIds: plan.excludedModuleIds,
     operations,
-    statePreview,
+    statePreview
   };
 }
 
@@ -800,5 +778,5 @@ module.exports = {
   createLegacyInstallPlan,
   getSourceRoot,
   listAvailableLanguages,
-  parseInstallArgs,
+  parseInstallArgs
 };
diff --git a/scripts/lib/transcript-context.js b/scripts/lib/transcript-context.js
index 4a00a551..c499523f 100644
--- a/scripts/lib/transcript-context.js
+++ b/scripts/lib/transcript-context.js
@@ -98,9 +98,7 @@ function readLatestContextTokens(transcriptPath, options = {}) {
     return null;
   }
 
-  const tailBytes = Number.isInteger(options.tailBytes) && options.tailBytes > 0
-    ? options.tailBytes
-    : DEFAULT_TRANSCRIPT_TAIL_BYTES;
+  const tailBytes = Number.isInteger(options.tailBytes) && options.tailBytes > 0 ? options.tailBytes : DEFAULT_TRANSCRIPT_TAIL_BYTES;
 
   const tail = readFileTail(transcriptPath, tailBytes);
   if (!tail) {
@@ -124,9 +122,7 @@ function readLatestContextTokens(transcriptPath, options = {}) {
 
     const tokens = extractUsageTokens(record);
     if (tokens > 0) {
-      const model = record.message && typeof record.message.model === 'string'
-        ? record.message.model
-        : '';
+      const model = record.message && typeof record.message.model === 'string' ? record.message.model : '';
       return { tokens, model };
     }
   }
@@ -141,6 +137,15 @@ function readLatestContextTokens(transcriptPath, options = {}) {
  * suffix); otherwise the standard 200k window.
  */
 function resolveContextWindowTokens(tokens, model) {
+  // Explicit window override wins: 400k models (e.g. Opus 4.x) match neither the
+  // 200k default nor the 1M marker and would otherwise report ~double usage (#2290).
+  // Honor ECC's own knob and Claude Code's native CLAUDE_CODE_AUTO_COMPACT_WINDOW.
+  const env = (typeof process !== 'undefined' && process.env) || {};
+  const envWindow = Number.parseInt(env.ECC_CONTEXT_WINDOW_TOKENS || env.CLAUDE_CODE_AUTO_COMPACT_WINDOW || '', 10);
+  if (Number.isInteger(envWindow) && envWindow > 0) {
+    return envWindow;
+  }
+
   if (typeof model === 'string' && model.includes(LARGE_WINDOW_MODEL_MARKER)) {
     return LARGE_CONTEXT_WINDOW_TOKENS;
   }
@@ -169,9 +174,7 @@ function resolveContextThreshold(env, windowTokens) {
     }
   }
 
-  return windowTokens >= LARGE_CONTEXT_WINDOW_TOKENS
-    ? DEFAULT_CONTEXT_THRESHOLD_LARGE
-    : DEFAULT_CONTEXT_THRESHOLD_STANDARD;
+  return windowTokens >= LARGE_CONTEXT_WINDOW_TOKENS ? DEFAULT_CONTEXT_THRESHOLD_LARGE : DEFAULT_CONTEXT_THRESHOLD_STANDARD;
 }
 
 /**
@@ -181,9 +184,7 @@ function resolveContextThreshold(env, windowTokens) {
 function resolveContextInterval(env) {
   const raw = env && env.COMPACT_CONTEXT_INTERVAL;
   const parsed = Number.parseInt(raw, 10);
-  return Number.isInteger(parsed) && parsed > 0 && parsed <= MAX_TOKEN_SETTING
-    ? parsed
-    : DEFAULT_CONTEXT_INTERVAL_TOKENS;
+  return Number.isInteger(parsed) && parsed > 0 && parsed <= MAX_TOKEN_SETTING ? parsed : DEFAULT_CONTEXT_INTERVAL_TOKENS;
 }
 
 /**
@@ -205,9 +206,7 @@ function computeContextBucket(tokens, threshold, interval) {
  * Human-readable label for a context window size (e.g. "200k", "1M").
  */
 function formatWindowLabel(windowTokens) {
-  return windowTokens >= LARGE_CONTEXT_WINDOW_TOKENS
-    ? '1M'
-    : `${Math.round(windowTokens / 1000)}k`;
+  return windowTokens >= LARGE_CONTEXT_WINDOW_TOKENS ? '1M' : `${Math.round(windowTokens / 1000)}k`;
 }
 
 module.exports = {
diff --git a/skills/cost-tracking/SKILL.md b/skills/cost-tracking/SKILL.md
index b07713f1..36fa80ab 100644
--- a/skills/cost-tracking/SKILL.md
+++ b/skills/cost-tracking/SKILL.md
@@ -1,148 +1,97 @@
 ---
 name: cost-tracking
-description: Track and report Claude Code token usage, spending, and budgets from a local cost-tracking database. Use when the user asks about costs, spending, usage, tokens, budgets, or cost breakdowns by project, tool, session, or date.
+description: Track and report Claude Code token usage, spending, and budgets from the local ECC cost-tracker metrics log. Use when the user asks about costs, spending, usage, tokens, budgets, or cost breakdowns by model, session, or date.
 metadata:
   origin: community
 ---
 
 # Cost Tracking
 
-Use this skill to analyze Claude Code cost and usage history from a local SQLite
-database. It is intended for users who already have a cost-tracking hook or
-plugin writing usage rows to `~/.claude-cost-tracker/usage.db`.
+Use this skill to analyze Claude Code cost and usage history from the metrics log
+that ECC's `stop:cost-tracker` hook writes.
 
-Source: salvaged from stale community PR #1304 by `MayurBhavsar`.
+## Where the data lives
+
+The tracker appends one JSON object per session-stop to
+`~/.claude/metrics/costs.jsonl`. Each row is a **cumulative snapshot for that
+session**, so to total spend you take the **latest row per `session_id`** and
+sum across sessions — summing every row multiply-counts.
+
+Row schema:
+
+| Field | Meaning |
+| --- | --- |
+| `timestamp` | ISO timestamp of the snapshot |
+| `session_id` | Claude Code session identifier |
+| `transcript_path` | Path to the session transcript |
+| `model` | Model used |
+| `input_tokens` / `output_tokens` | Token counts |
+| `cache_write_tokens` / `cache_read_tokens` | Prompt-cache token counts |
+| `estimated_cost_usd` | Precomputed cumulative cost in USD for the session |
+
+Prefer `estimated_cost_usd` over hand-calculating pricing — model and cache
+prices change, and the tracker is the source of truth.
 
 ## When to Use
 
 - The user asks "how much have I spent?", "what did this session cost?", or
   "what is my token usage?"
 - The user mentions budgets, spending limits, overruns, or cost controls.
-- The user wants a cost breakdown by project, tool, session, model, or date.
-- The user wants to compare today against yesterday or inspect a recent trend.
-- The user asks for a CSV export of recent usage records.
+- The user wants a cost breakdown by model, session, or date, or a CSV export.
 
 ## How It Works
 
-First verify prerequisites:
+First verify the log exists (use `node`, not `sqlite3` — the tracker writes
+JSONL, and `node` is cross-platform):
 
 ```bash
-command -v sqlite3 >/dev/null && echo "sqlite3 available" || echo "sqlite3 missing"
-test -f ~/.claude-cost-tracker/usage.db && echo "Database found" || echo "Database not found"
+node -e 'const fs=require("fs"),os=require("os"),p=require("path");const f=p.join(os.homedir(),".claude","metrics","costs.jsonl");console.log(fs.existsSync(f)?"cost log found":"cost log not found: "+f)'
 ```
 
-If the database is missing, do not fabricate usage data. Tell the user that cost
-tracking is not configured and suggest installing or enabling a trusted local
-cost-tracking hook/plugin.
+If the log is missing, do not fabricate usage data. Tell the user that cost
+tracking populates after the first session ends with the `stop:cost-tracker`
+hook enabled.
 
-The expected `usage` table usually contains one row per tool call or model
-interaction. Column names vary by tracker, but the examples below assume:
-
-| Column | Meaning |
-| --- | --- |
-| `timestamp` | ISO timestamp for the usage event |
-| `project` | Project or repository name |
-| `tool_name` | Tool or event name |
-| `input_tokens` | Input token count, when recorded |
-| `output_tokens` | Output token count, when recorded |
-| `cost_usd` | Precomputed cost in USD |
-| `session_id` | Claude Code session identifier |
-| `model` | Model used for the event |
-
-Prefer `cost_usd` over hand-calculating pricing. Model prices and cache pricing
-change over time, and the tracker should be the source of truth for how each row
-was priced.
-
-## Examples
-
-### Quick Summary
+## Example — summary, by model, last 7 days
 
 ```bash
-sqlite3 ~/.claude-cost-tracker/usage.db "
-  SELECT
-    'Today: $' || ROUND(COALESCE(SUM(CASE WHEN date(timestamp) = date('now') THEN cost_usd END), 0), 4) ||
-    ' | Total: $' || ROUND(COALESCE(SUM(cost_usd), 0), 4) ||
-    ' | Calls: ' || COUNT(*) ||
-    ' | Sessions: ' || COUNT(DISTINCT session_id)
-  FROM usage;
-"
+node -e '
+const fs=require("fs"),os=require("os"),path=require("path");
+const f=path.join(os.homedir(),".claude","metrics","costs.jsonl");
+if(!fs.existsSync(f)){console.log("cost log not found: "+f);process.exit(0);}
+const rows=fs.readFileSync(f,"utf8").split(/\r?\n/).filter(Boolean).map(l=>{try{return JSON.parse(l)}catch{return null}}).filter(Boolean);
+const bySession=new Map();
+for(const r of rows){const k=r.session_id||r.transcript_path||r.timestamp;const p=bySession.get(k);if(!p||String(r.timestamp)>String(p.timestamp))bySession.set(k,r);}
+const latest=[...bySession.values()];
+const cost=r=>Number(r.estimated_cost_usd)||0, day=r=>String(r.timestamp||"").slice(0,10), sum=a=>a.reduce((s,r)=>s+cost(r),0), f4=n=>"$"+n.toFixed(4);
+const today=new Date().toISOString().slice(0,10), yest=new Date(Date.now()-864e5).toISOString().slice(0,10);
+console.log("today: "+f4(sum(latest.filter(r=>day(r)===today)))+" | yesterday: "+f4(sum(latest.filter(r=>day(r)===yest)))+" | total: "+f4(sum(latest))+" ("+latest.length+" sessions)");
+const m=new Map();for(const r of latest){const k=r.model||"(unknown)";m.set(k,(m.get(k)||0)+cost(r));}
+console.log("by model:");[...m.entries()].sort((a,b)=>b[1]-a[1]).forEach(([k,v])=>console.log("  "+f4(v)+"  "+k));
+'
 ```
 
-### Cost By Project
-
-```bash
-sqlite3 -header -column ~/.claude-cost-tracker/usage.db "
-  SELECT project, ROUND(SUM(cost_usd), 4) AS cost, COUNT(*) AS calls
-  FROM usage
-  GROUP BY project
-  ORDER BY cost DESC;
-"
-```
-
-### Cost By Tool
-
-```bash
-sqlite3 -header -column ~/.claude-cost-tracker/usage.db "
-  SELECT tool_name, ROUND(SUM(cost_usd), 4) AS cost, COUNT(*) AS calls
-  FROM usage
-  GROUP BY tool_name
-  ORDER BY cost DESC;
-"
-```
-
-### Last Seven Days
-
-```bash
-sqlite3 -header -column ~/.claude-cost-tracker/usage.db "
-  SELECT date(timestamp) AS date, ROUND(SUM(cost_usd), 4) AS cost, COUNT(*) AS calls
-  FROM usage
-  GROUP BY date(timestamp)
-  ORDER BY date DESC
-  LIMIT 7;
-"
-```
-
-### Session Drilldown
-
-```bash
-sqlite3 -header -column ~/.claude-cost-tracker/usage.db "
-  SELECT session_id,
-    MIN(timestamp) AS started,
-    MAX(timestamp) AS ended,
-    ROUND(SUM(cost_usd), 4) AS cost,
-    COUNT(*) AS calls
-  FROM usage
-  GROUP BY session_id
-  ORDER BY started DESC
-  LIMIT 10;
-"
-```
+For a session drilldown or CSV export, iterate the same `latest` set (or the raw
+rows for CSV) and print the fields you need.
 
 ## Reporting Guidance
 
-When presenting cost data, include:
-
-1. Today's spend and yesterday comparison.
-2. Total spend across the tracked database.
-3. Top projects ranked by cost.
-4. Top tools ranked by cost.
-5. Session count and average cost per session when enough data exists.
-
-For small amounts, format currency with four decimal places. For larger amounts,
-two decimals are enough.
+When presenting cost data, include today's spend vs yesterday, total across all
+sessions, a by-model breakdown, and session count. Format sub-dollar amounts
+with four decimals, larger amounts with two.
 
 ## Anti-Patterns
 
-- Do not estimate costs from raw token counts when `cost_usd` is present.
-- Do not assume the database exists without checking.
-- Do not run unbounded `SELECT *` exports on large databases.
+- Do not sum every row — they are cumulative per session; reduce to the latest
+  row per `session_id` first.
+- Do not estimate costs from raw token counts when `estimated_cost_usd` is present.
+- Do not assume the log exists without checking.
 - Do not hard-code current model pricing in user-facing answers.
-- Do not recommend installing unreviewed hooks or plugins that execute arbitrary
-  code.
+- Do not recommend installing unreviewed hooks or plugins that execute arbitrary code.
 
 ## Related
 
-- `/cost-report` - Command-form report using the same database.
+- `/cost-report` - Command-form report over the same metrics log.
 - `cost-aware-llm-pipeline` - Model-routing and budget-design patterns.
 - `token-budget-advisor` - Context and token-budget planning.
 - `strategic-compact` - Context compaction to reduce repeated token spend.
diff --git a/tests/lib/transcript-context.test.js b/tests/lib/transcript-context.test.js
index e6df6565..96615fe4 100644
--- a/tests/lib/transcript-context.test.js
+++ b/tests/lib/transcript-context.test.js
@@ -78,47 +78,32 @@ function tracked(filePath) {
 console.log('readLatestContextTokens:');
 
 test('sums input + cache_read + cache_creation from the latest usage record', () => {
-  const file = tracked(writeTranscript([
-    usageRecord({ input: 10, cacheRead: 20, cacheCreation: 5 }),
-    usageRecord({ input: 100, cacheRead: 150000, cacheCreation: 7000 })
-  ]));
+  const file = tracked(writeTranscript([usageRecord({ input: 10, cacheRead: 20, cacheCreation: 5 }), usageRecord({ input: 100, cacheRead: 150000, cacheCreation: 7000 })]));
   const result = readLatestContextTokens(file);
   assert.ok(result, 'Expected a usage result');
   assert.strictEqual(result.tokens, 157100);
 });
 
 test('returns the model id alongside the token count', () => {
-  const file = tracked(writeTranscript([
-    usageRecord({ input: 1000 }, 'claude-opus-4-5[1m]')
-  ]));
+  const file = tracked(writeTranscript([usageRecord({ input: 1000 }, 'claude-opus-4-5[1m]')]));
   const result = readLatestContextTokens(file);
   assert.strictEqual(result.model, 'claude-opus-4-5[1m]');
 });
 
 test('skips trailing records without usage (e.g. tool results)', () => {
-  const file = tracked(writeTranscript([
-    usageRecord({ input: 5000 }),
-    JSON.stringify({ type: 'user', message: { content: 'tool result' } }),
-    JSON.stringify({ type: 'system', subtype: 'info' })
-  ]));
+  const file = tracked(writeTranscript([usageRecord({ input: 5000 }), JSON.stringify({ type: 'user', message: { content: 'tool result' } }), JSON.stringify({ type: 'system', subtype: 'info' })]));
   const result = readLatestContextTokens(file);
   assert.strictEqual(result.tokens, 5000);
 });
 
 test('skips malformed JSONL lines without throwing', () => {
-  const file = tracked(writeTranscript([
-    usageRecord({ input: 4200 }),
-    '{not json at all',
-    ''
-  ]));
+  const file = tracked(writeTranscript([usageRecord({ input: 4200 }), '{not json at all', '']));
   const result = readLatestContextTokens(file);
   assert.strictEqual(result.tokens, 4200);
 });
 
 test('returns null for a transcript with no usage records', () => {
-  const file = tracked(writeTranscript([
-    JSON.stringify({ type: 'user', message: { content: 'hello' } })
-  ]));
+  const file = tracked(writeTranscript([JSON.stringify({ type: 'user', message: { content: 'hello' } })]));
   assert.strictEqual(readLatestContextTokens(file), null);
 });
 
@@ -132,10 +117,7 @@ test('returns null for empty or non-string paths', () => {
 });
 
 test('ignores zero-token usage records', () => {
-  const file = tracked(writeTranscript([
-    usageRecord({ input: 999 }),
-    usageRecord({ input: 0 })
-  ]));
+  const file = tracked(writeTranscript([usageRecord({ input: 999 }), usageRecord({ input: 0 })]));
   const result = readLatestContextTokens(file);
   assert.strictEqual(result.tokens, 999);
 });
@@ -154,10 +136,42 @@ test('only scans the transcript tail (latest records win on large files)', () =>
 // ── resolveContextWindowTokens ──
 console.log('\nresolveContextWindowTokens:');
 
+// Isolation: an env-set window override (either knob) otherwise leaks into the
+// default-window assertions below and fails them (#2290).
+delete process.env.ECC_CONTEXT_WINDOW_TOKENS;
+delete process.env.CLAUDE_CODE_AUTO_COMPACT_WINDOW;
+
 test('defaults to the standard 200k window', () => {
   assert.strictEqual(resolveContextWindowTokens(50000, 'claude-sonnet-4-6'), STANDARD_CONTEXT_WINDOW_TOKENS);
 });
 
+test('honors an explicit ECC_CONTEXT_WINDOW_TOKENS override (e.g. 400k models, #2290)', () => {
+  process.env.ECC_CONTEXT_WINDOW_TOKENS = '400000';
+  try {
+    assert.strictEqual(resolveContextWindowTokens(50000, 'claude-opus-4-x'), 400000);
+  } finally {
+    delete process.env.ECC_CONTEXT_WINDOW_TOKENS;
+  }
+});
+
+test('honors Claude Code native CLAUDE_CODE_AUTO_COMPACT_WINDOW override', () => {
+  process.env.CLAUDE_CODE_AUTO_COMPACT_WINDOW = '400000';
+  try {
+    assert.strictEqual(resolveContextWindowTokens(50000, 'claude-opus-4-x'), 400000);
+  } finally {
+    delete process.env.CLAUDE_CODE_AUTO_COMPACT_WINDOW;
+  }
+});
+
+test('ignores a non-positive / invalid window override', () => {
+  process.env.ECC_CONTEXT_WINDOW_TOKENS = 'not-a-number';
+  try {
+    assert.strictEqual(resolveContextWindowTokens(50000, 'claude-sonnet-4-6'), STANDARD_CONTEXT_WINDOW_TOKENS);
+  } finally {
+    delete process.env.ECC_CONTEXT_WINDOW_TOKENS;
+  }
+});
+
 test('detects a 1M window from the [1m] model marker', () => {
   assert.strictEqual(resolveContextWindowTokens(50000, 'claude-opus-4-5[1m]'), LARGE_CONTEXT_WINDOW_TOKENS);
 });
@@ -191,11 +205,7 @@ test('COMPACT_CONTEXT_THRESHOLD=0 disables the signal', () => {
 
 test('invalid COMPACT_CONTEXT_THRESHOLD falls back to the default', () => {
   for (const bad of ['-5', 'abc', '99999999999']) {
-    assert.strictEqual(
-      resolveContextThreshold({ COMPACT_CONTEXT_THRESHOLD: bad }, STANDARD_CONTEXT_WINDOW_TOKENS),
-      DEFAULT_CONTEXT_THRESHOLD_STANDARD,
-      `Expected fallback for ${bad}`
-    );
+    assert.strictEqual(resolveContextThreshold({ COMPACT_CONTEXT_THRESHOLD: bad }, STANDARD_CONTEXT_WINDOW_TOKENS), DEFAULT_CONTEXT_THRESHOLD_STANDARD, `Expected fallback for ${bad}`);
   }
 });