Every Inc has open-sourced Proof SDK, the document infrastructure behind its hosted editor at proofeditor.ai, under an MIT license. The release covers the full monorepo as five npm packages — doc-core, doc-editor, doc-server, doc-store-sqlite, and agent-bridge — providing a self-hostable collaborative markdown environment where every edit is attributed to its author, whether human or AI.
The agent-bridge package exposes an HTTP interface at /documents/:slug/bridge/ through which AI agents can interact with documents using the same operations as human editors: reading document state and snapshots, posting comments and suggestions, submitting edits, triggering rewrites, managing marks, and registering presence. Every Inc has published an AGENT_CONTRACT.md in the repo that formally specifies what behavior agents can expect from those routes — a versioned spec intended to keep the interface stable as the SDK evolves.
The SDK ships with documented support for Claude Code, ChatGPT, and Codex. Every Inc describes the target use cases as iterative knowledge-work documents — product requirements, bug reports, research briefs, and implementation plans — where humans and agents work through drafts together. The hosted product at proofeditor.ai has reportedly hit load-related outages; the company has not publicly addressed them.
Every Inc did not respond to a request for comment before publication. The packages are available on npm now.