Sigill — AI Conversation Timestamper

Sigill turns your AI conversations into verifiable evidence. Every completed conversation turn on claude.ai, chatgpt.com and gemini.google.com is captured from the platform's own response stream — real message IDs, the actual model identifier, and true completion events, not screen scraping. Each turn becomes a structured evidence envelope that is canonicalized (RFC 8785), hashed (SHA-256), and timestamped by an RFC 3161 Timestamp Authority with optional Cades sealing. Privacy by architecture: your conversation content never leaves the browser. Only a cryptographic hash is sent for timestamping. Files you attach and files the AI generates are recorded by hash as well. Your evidence log is a chained, tamper-evident ledger stored locally, with hourly integrity anchors. Export it as a self-contained bundle that anyone can verify offline with standard tools — no Sigill account required to check the proofs. Why it matters: when an AI conversation becomes a dispute — what was asked, what was answered, when — logs you can edit prove nothing. Sigill gives each turn an independent, cryptographic timestamp at the moment it happened. Requires a free API key from sigill.ai. Works with Claude, ChatGPT and Gemini.