perf: async tokenization with worker threads

Tokenization now runs in worker threads to prevent blocking during
heavy encoding operations, maintaining UI responsiveness.

Previous synchronous approach with fallback approximations caused
UI lag when calculating token counts for large chat histories. Moving
tokenization off the main thread keeps the UI responsive at 60fps
even during expensive tokenization workloads.

Key changes:
- Worker thread pool using node:worker_threads
- All tokenizer APIs converted to async
- IPC channels for renderer-side tokenization
- Frontend LRU cache with Suspense integration
- Real-time token estimates in ChatInput
- Updated ~50 test files for async API

Author: ThomasK33

.github/workflows/chromatic.yml

@@ -36,4 +36,3 @@ jobs:
           projectToken: ${{ secrets.CHROMATIC_PROJECT_TOKEN }}
           exitZeroOnChanges: true
           onlyChanged: true
-

.github/workflows/ci.yml

@@ -74,6 +74,9 @@ jobs:
 
       - uses: ./.github/actions/setup-cmux
 
+      - name: Build worker files
+        run: make build-main
+
       - name: Run tests with coverage
         run: bun test --coverage --coverage-reporter=lcov ${{ github.event.inputs.test_filter || 'src' }}
 
@@ -96,6 +99,9 @@ jobs:
 
       - uses: ./.github/actions/setup-cmux
 
+      - name: Build worker files
+        run: make build-main
+
       - name: Run integration tests with coverage
         # --silent suppresses per-test output (17 test files × 32 workers = overwhelming logs)
         run: TEST_INTEGRATION=1 bun x jest --coverage --maxWorkers=100% --silent ${{ github.event.inputs.test_filter || 'tests' }}

.github/workflows/nightly-terminal-bench.yml

@@ -3,13 +3,13 @@ name: Nightly Terminal-Bench
 on:
   schedule:
     # Run full benchmark suite (~80 tasks) every night at midnight UTC
-    - cron: '0 0 * * *'
+    - cron: "0 0 * * *"
   workflow_dispatch:
     inputs:
       models:
         description: 'Models to test (comma-separated, or "all" for both)'
         required: false
-        default: 'all'
+        default: "all"
         type: string
 
 jobs:
@@ -41,9 +41,9 @@ jobs:
     uses: ./.github/workflows/terminal-bench.yml
     with:
       model_name: ${{ matrix.model }}
-      thinking_level: 'high'
-      dataset: 'terminal-bench-core==0.1.1'
-      concurrency: '4'
+      thinking_level: "high"
+      dataset: "terminal-bench-core==0.1.1"
+      concurrency: "4"
       livestream: true
     secrets:
       ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}

.github/workflows/publish-npm.yml

@@ -5,7 +5,7 @@ on:
     branches:
       - main
     tags:
-      - 'v*'
+      - "v*"
   workflow_dispatch:
 
 permissions:
@@ -24,12 +24,12 @@ jobs:
 
       - uses: ./.github/actions/setup-cmux
         with:
-          install-imagemagick: 'true'
+          install-imagemagick: "true"
 
       # Sets up .npmrc with the auth token
       - uses: actions/setup-node@v4
         with:
-          registry-url: 'https://registry.npmjs.org'
+          registry-url: "https://registry.npmjs.org"
 
       - run: sudo npm i -g npm@latest
 
@@ -38,10 +38,10 @@ jobs:
         run: |
           # Get base version from package.json
           BASE_VERSION=$(node -p "require('./package.json').version")
-          
+
           # Generate git describe version
           GIT_DESCRIBE=$(git describe --tags --always --dirty 2>/dev/null || echo "unknown")
-          
+
           if [[ $GITHUB_REF == refs/tags/* ]]; then
             # For tags, use the base version as-is (stable release)
             NPM_VERSION="${BASE_VERSION}"
@@ -56,13 +56,13 @@ jobs:
             NPM_TAG="next"
             echo "Publishing pre-release: ${NPM_VERSION}"
           fi
-          
+
           echo "version=${NPM_VERSION}" >> $GITHUB_OUTPUT
           echo "tag=${NPM_TAG}" >> $GITHUB_OUTPUT
-          
+
           # Update package.json with the new version
           node -e "const fs = require('fs'); const pkg = JSON.parse(fs.readFileSync('package.json')); pkg.version = '${NPM_VERSION}'; fs.writeFileSync('package.json', JSON.stringify(pkg, null, 2) + '\n');"
-          
+
           echo "Updated package.json to version ${NPM_VERSION}"
 
       - name: Generate version file
@@ -76,7 +76,7 @@ jobs:
         run: |
           PACKAGE_NAME=$(node -p "require('./package.json').name")
           VERSION="${{ steps.version.outputs.version }}"
-          
+
           if npm view "${PACKAGE_NAME}@${VERSION}" version &>/dev/null; then
             echo "exists=true" >> $GITHUB_OUTPUT
             echo "Version ${VERSION} already exists on npm"
@@ -95,7 +95,7 @@ jobs:
           PACKAGE_NAME=$(node -p "require('./package.json').name")
           VERSION="${{ steps.version.outputs.version }}"
           TAG="${{ steps.version.outputs.tag }}"
-          
+
           echo "Version ${VERSION} already published, updating dist-tag to ${TAG}"
           npm dist-tag add "${PACKAGE_NAME}@${VERSION}" "${TAG}"
 

.github/workflows/terminal-bench.yml

@@ -4,34 +4,34 @@ on:
   workflow_call:
     inputs:
       model_name:
-        description: 'Model to use (e.g., anthropic:claude-sonnet-4-5)'
+        description: "Model to use (e.g., anthropic:claude-sonnet-4-5)"
         required: false
         type: string
       thinking_level:
-        description: 'Thinking level (off, low, medium, high)'
+        description: "Thinking level (off, low, medium, high)"
         required: false
         type: string
       dataset:
-        description: 'Terminal-Bench dataset to use'
+        description: "Terminal-Bench dataset to use"
         required: false
         type: string
-        default: 'terminal-bench-core==0.1.1'
+        default: "terminal-bench-core==0.1.1"
       concurrency:
-        description: 'Number of concurrent tasks (--n-concurrent)'
+        description: "Number of concurrent tasks (--n-concurrent)"
         required: false
         type: string
-        default: '4'
+        default: "4"
       livestream:
-        description: 'Enable livestream mode'
+        description: "Enable livestream mode"
         required: false
         type: boolean
         default: true
       sample_size:
-        description: 'Number of random tasks to run (empty = all tasks)'
+        description: "Number of random tasks to run (empty = all tasks)"
         required: false
         type: string
       extra_args:
-        description: 'Additional arguments to pass to terminal-bench'
+        description: "Additional arguments to pass to terminal-bench"
         required: false
         type: string
     secrets:
@@ -42,34 +42,34 @@ on:
   workflow_dispatch:
     inputs:
       dataset:
-        description: 'Terminal-Bench dataset to use'
+        description: "Terminal-Bench dataset to use"
         required: false
-        default: 'terminal-bench-core==0.1.1'
+        default: "terminal-bench-core==0.1.1"
         type: string
       concurrency:
-        description: 'Number of concurrent tasks (--n-concurrent)'
+        description: "Number of concurrent tasks (--n-concurrent)"
         required: false
-        default: '4'
+        default: "4"
         type: string
       livestream:
-        description: 'Enable livestream mode'
+        description: "Enable livestream mode"
         required: false
         default: true
         type: boolean
       sample_size:
-        description: 'Number of random tasks to run (empty = all tasks)'
+        description: "Number of random tasks to run (empty = all tasks)"
         required: false
         type: string
       model_name:
-        description: 'Model to use (e.g., anthropic:claude-sonnet-4-5, openai:gpt-5-codex)'
+        description: "Model to use (e.g., anthropic:claude-sonnet-4-5, openai:gpt-5-codex)"
         required: false
         type: string
       thinking_level:
-        description: 'Thinking level (off, low, medium, high)'
+        description: "Thinking level (off, low, medium, high)"
         required: false
         type: string
       extra_args:
-        description: 'Additional arguments to pass to terminal-bench'
+        description: "Additional arguments to pass to terminal-bench"
         required: false
         type: string
 
@@ -148,4 +148,3 @@ jobs:
             runs/
           if-no-files-found: warn
           retention-days: 30
-

.storybook/main.ts

@@ -4,11 +4,7 @@ import path from "path";
 
 const config: StorybookConfig = {
   stories: ["../src/**/*.stories.@(ts|tsx)"],
-  addons: [
-    "@storybook/addon-links",
-    "@storybook/addon-docs",
-    "@storybook/addon-interactions",
-  ],
+  addons: ["@storybook/addon-links", "@storybook/addon-docs", "@storybook/addon-interactions"],
   framework: {
     name: "@storybook/react-vite",
     options: {},

.storybook/mocks/version.ts

@@ -6,4 +6,3 @@ export const VERSION = {
   git_describe: "v1.0.0",
   buildTime: "2024-01-24T17:41:00Z", // 9:41 AM PST
 };
-

Makefile

@@ -203,11 +203,11 @@ check-deadcode: node_modules/.installed ## Check for potential dead code (manual
 		|| echo "✓ No obvious dead code found"
 
 ## Testing
-test-integration: node_modules/.installed ## Run all tests (unit + integration)
+test-integration: node_modules/.installed build-main ## Run all tests (unit + integration)
 	@bun test src
 	@TEST_INTEGRATION=1 bun x jest tests
 
-test-unit: node_modules/.installed ## Run unit tests
+test-unit: node_modules/.installed build-main ## Run unit tests
 	@bun test src
 
 test: test-unit ## Alias for test-unit
@@ -220,7 +220,7 @@ test-coverage: ## Run tests with coverage
 
 test-e2e: ## Run end-to-end tests
 	@$(MAKE) build
-	@CMUX_E2E_LOAD_DIST=1 CMUX_E2E_SKIP_BUILD=1 PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1 bun x playwright test --project=electron
+	@CMUX_E2E_LOAD_DIST=1 CMUX_E2E_SKIP_BUILD=1 PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1 bun x playwright test --project=electron $(PLAYWRIGHT_ARGS)
 
 ## Distribution
 dist: build ## Build distributable packages

benchmarks/terminal_bench/README.md

@@ -36,6 +36,7 @@ The benchmark uses a **global timeout** applied to all tasks. The default is **3
 **Design Rationale:**
 
 Based on analysis of Oct 30, 2025 nightly runs:
+
 - Longest successful task: `blind-maze-explorer-algorithm.hard` at 20 minutes
 - 95th percentile: ~15 minutes
 - Mean duration: ~6 minutes