Server-side implementation for reading, parsing, and exporting Claude
Code session logs:
session-discovery.ts:
- Walks ~/.claude/projects/ directories, reads sessions-index.json from
each project folder, supports both the current {version, entries}
format and the legacy raw array format
- Aggregates sessions across all projects, sorted by most recently
modified first
- Gracefully handles missing directories, corrupt index files, and
missing entries
session-parser.ts:
- Parses Claude Code JSONL session files line-by-line into normalized
ParsedMessage objects
- Handles the full real-world format: type="user" (string or
ContentBlock array content), type="assistant" (text, thinking,
tool_use blocks), type="progress" (hook events with structured data
fields), type="summary" (summary text field), type="file-history-
snapshot", and silently skips type="system" (turn_duration metadata)
and type="queue-operation" (internal)
- Detects <system-reminder> tags in user messages and reclassifies them
as system_message category
- Resilient to malformed JSONL lines (skips with continue, no crash)
html-exporter.ts:
- Generates self-contained HTML exports with no external dependencies —
all CSS (layout, category-specific colors, syntax highlighting) is
inlined in a <style> block
- Dark theme (GitHub dark palette) with category-specific left border
colors and backgrounds matching the Claude Code aesthetic
- Renders markdown content via marked + highlight.js with syntax
highlighting, inserts "content redacted" dividers where redacted
messages were removed
- Outputs a complete <!DOCTYPE html> document with session metadata
header (project name, date, message count)
routes/sessions.ts:
- GET /api/sessions — returns all discovered sessions with 30-second
in-memory cache to avoid re-scanning the filesystem on every request
- GET /api/sessions/:id — looks up session by ID from cache, parses
the JSONL file, returns parsed messages
routes/export.ts:
- POST /api/export — accepts ExportRequest body, validates required
fields, generates HTML via the exporter, returns as a downloadable
attachment with sanitized filename
index.ts:
- Express app factory (createApp) with 50MB JSON body limit, health
check endpoint, session and export routers, and static file serving
for the built client
- Dual-bind to localhost and Tailscale IP (100.84.4.113) for local +
tailnet access, with optional browser-open on startup via
SESSION_VIEWER_OPEN_BROWSER env var
- Auto-start guard: only calls startServer() when run directly, not
when imported by tests
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Shared module consumed by both the Express server and the React client:
types.ts:
- ParsedMessage: the normalized message unit (uuid, category, content,
toolName, toolInput, timestamp, rawIndex) that the parser emits and
every downstream consumer (viewer, filter, export) operates on
- MessageCategory: 9-value union covering user_message, assistant_text,
thinking, tool_call, tool_result, system_message, hook_progress,
file_snapshot, and summary
- SessionEntry / SessionListResponse / SessionDetailResponse / ExportRequest:
API contract types for the sessions list, session detail, and HTML
export endpoints
- ALL_CATEGORIES, CATEGORY_LABELS, DEFAULT_HIDDEN_CATEGORIES: constants
for the filter panel UI and presets (thinking + hook_progress hidden
by default)
sensitive-redactor.ts:
- 34 regex patterns derived from gitleaks production config, organized
into Tier 1 (known secret formats: AWS, GitHub, GitLab, OpenAI,
Anthropic, HuggingFace, Perplexity, Stripe, Slack, SendGrid, Twilio,
GCP, Azure AD, Heroku, npm, PyPI, Sentry, JWT, PEM private keys,
generic API key assignments) and Tier 2 (PII/system info: home
directory paths, connection strings, URLs with credentials, email
addresses, IPv4 addresses, Bearer tokens, env var secret assignments)
- Keyword pre-filtering: each pattern declares keywords that must appear
in the text before the expensive regex is evaluated, following the
gitleaks performance optimization approach
- False-positive allowlists: example/test email domains, localhost/
documentation IPs (RFC 5737), noreply@anthropic.com
- Pure functions: redactSensitiveContent returns {sanitized, count,
categories}, redactString returns just the string, redactMessage
returns a new ParsedMessage with content and toolInput redacted
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Initialize the session-viewer project — a tool for browsing, filtering,
redacting, and exporting Claude Code session logs as self-contained HTML.
Scaffolding includes:
- package.json with Express server + React client dual-stack setup,
dev/build/test/lint/typecheck scripts, and a CLI bin entry point
- TypeScript configs: base tsconfig.json (ESNext, bundler resolution,
strict, react-jsx) and tsconfig.server.json extending it for the
Express server compilation target
- Vite config: React plugin, Tailscale-aware dev server on :3847 with
API proxy to :3848, client build output to dist/client
- Vitest config: node environment, test discovery from tests/unit and
src/client/components
- ESLint flat config: typescript-eslint recommended, unused-vars with
underscore exception
- Tailwind CSS config scoped to src/client, PostCSS with autoprefixer
- Playwright config: Chromium-only E2E against dev server
- bin/session-viewer.js: CLI entry point that re-execs via tsx with
browser-open flag
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
