Halo – Tamper-evident runtime evidence for AI agents

Show HN: Halo – open-source, tamper-evident runtime evidence for AI agents

Halo is an open-source tool creating tamper-evident runtime records for AI agents, ensuring an audit trail that vendors cannot edit. It transforms every agent action, including tool calls and data access, into an append-only, hash-chained log verifiable by anyone without trust. With zero runtime dependencies and a focus on security, Halo allows developers to provide customers with a verifiable link instead of written assurances. It integrates seamlessly with existing stacks like OpenTelemetry, LangChain, and the Vercel AI SDK, offering a robust solution for compliance frameworks such as SOC 2 and the EU AI Act.

"When a customer's security team asks 'what did your agent do with our data?', you hand them a link instead of a paragraph."