VAC: Vector Access Protocol

[giusmarci]

Explainer:
https://github.com/giusmarci/vac-vector-access-protocol/blob/main/docs/explainer.md

Specification URL (optional):
https://github.com/giusmarci/vac-vector-access-protocol

Summary:
VAC (Vector Access Protocol) is a proposed open web standard that enables websites to expose semantically meaningful vector embeddings to LLMs and AI agents. It introduces a discoverable .well-known/vectors.json file, similar to robots.txt or ads.txt, to describe site content in a format optimized for machine understanding. Future extensions support live querying via endpoints like /vac/query.

VAC empowers AI systems to understand content rather than scrape HTML heuristically, paving the way for semantic web browsing, vector-native search engines, and privacy-safe AI indexing.

Relationship to other specs:

Similar discoverability pattern to .well-known files (robots.txt, ads.txt, manifest.json)

Complements existing metadata systems like schema.org and OpenGraph, but optimized for machine understanding via vector embeddings

Can integrate with or extend OpenAPI or MCP-based protocols for dynamic querying

Preferred venue for discussion:
GitHub Discussions

Impact on privacy / security:
VAC does not require user data or cookies. Embedding vectors of public pages is equivalent to publishing readable summaries or semantic metadata. VAC avoids scraping and encourages intentional AI-friendly content sharing.

GitHub usernames of submitters:
@giusmarci

[liminzhu]

This is not the right repo for filing proposal, but I see you already posted in the right place which is great WICG/proposals#222.