Hash-chained, Ed25519-signed audit trails. Prove what your agent did — to auditors, customers, and yourself.
Three steps to verifiable agent behavior.
Record every action with cryptographic proof. Each receipt is Ed25519-signed and timestamped.
Build tamper-proof audit trails per agent. Each receipt hashes its predecessor — no gaps, no rewrites.
Anyone can verify any receipt, anytime. Open format, no vendor lock-in, independently auditable.
Drop in via MCP or use the SDK directly. Two lines to your first attestation.
// .claude/settings.json { "mcpServers": { "sigil": { "command": "uvx", "args": ["sigil-notary"], "env": { "SIGIL_API_KEY": "sg_..." } } } }
from sigil import SigilClient client = SigilClient(api_key="sg_...") receipt = client.attest( "file_write", {"path": "/src/main.py"} ) # receipt.receipt_hash → "a3f8..." # receipt.seq → 17 # receipt.signature → Ed25519
Open source today. Hosted services coming soon.
The Sigil MCP server and SDK are MIT-licensed. Audit the code that audits your agents.