Security: Reject session paths containing '..' traversal segments or
non-.jsonl extensions before resolving them. This prevents a malicious
sessions-index.json from tricking the viewer into reading arbitrary files.
Performance: Process all project directories concurrently with Promise.all
instead of sequentially awaiting each one. Each directory's stat + readFile
is independent I/O that benefits from parallelism.
Add test case verifying that traversal paths and non-JSONL paths are rejected
while valid paths pass through.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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>
