Chron

What is Chron?

Chron is an MCP server that provides a timestamped audit trail for every AI conversation. It logs each exchange with precise local datetime (including timezone offset) to a local SQLite file you own. Works with Claude Desktop, Claude Code, Cursor, Windsurf, and any MCP-compatible AI tool.

How to use Chron?

Add the server to your AI tool’s MCP configuration by setting command to npx and args to ["-y", "chron-mcp"]. First run automatically creates ~/.chron/chron.db. For Claude Code, additionally install the companion skill hook to enable automatic session logging. Run as HTTP+SSE for team/self-hosted use by setting CHRON_TRANSPORT=http.

Key features of Chron

• Logs user and assistant timestamps with timezone offset
• Stores audit trail in a local SQLite file you own
• Tamper-evident SHA-256 hash chaining
• Companion skill file for automatic logging
• HTTP+SSE mode for remote/team usage
• Works with any MCP-compatible AI tool

Use cases of Chron

• Audit AI conversation timestamps and response generation time
• Retrieve full conversation history with exact timing across sessions
• Verify message integrity after logging via hash chain verification
• Self-host a shared audit trail for a team’s AI interactions
• Query your entire conversation log directly with SQLite tools

FAQ from Chron

What data does Chron log?

Every exchange records the user message’s received timestamp and the assistant response’s sent timestamp, along with full content and session metadata.

Where is my data stored?

Your audit log lives in a single SQLite file at ~/.chron/chron.db (configurable via CHRON_DB_PATH). No data leaves your machine; no cloud or telemetry.

How does tamper-evident hashing work?

Each message is linked to the previous one via a SHA-256 chain. The verify_session tool walks the chain and reports whether any message has been modified post-logging and the exact row of the first break.

Which AI tools does Chron support?

Claude Desktop, Claude Code, Cursor, Windsurf, and any MCP-compatible AI tool. Installation instructions are provided for each.

Do I need an API key for normal use?

No. In stdio mode (default) no API key is required. An API key is optional and only needed when using HTTP+SSE mode.