---
title: "LLM-Ready File Specification (LRFS) v1.0 | LLMind"
description: "The LLM-Ready File Specification (LRFS) defines the XMP namespace, signing scheme, and semantic-layer format for making files readable by any AI tool."
url: https://llmind.org/spec/
source_format: html
---
# LLM-Ready File Specification (LRFS)

Version 1.0 · Released · Published 2026-04-22

LRFS defines how a file embeds a signed, tamper-evident semantic layer in its XMP metadata, so any AI tool can read the file's meaning without re-parsing or re-OCR.

## Status

This is **v1.0 released**. The LRFS namespace URI `https://llmind.org/ns/1.0/` is stable and will remain unchanged throughout the v1.x family. Breaking changes will use `/ns/2.0/` and leave 1.0 untouched forever.

## Scope

The LRFS specifies:

-   The XMP namespace URI, fields, and value types
-   The per-layer HMAC-SHA256 signing scheme and file-checksum binding
-   The version-chain format (immutable layer history)
-   How readers detect, validate, and extract layers

## Consolidated view

The [full specification on one page](https://llmind.org/spec/lrfs-v1.0/) is the citation-ready URL covering all three chapters in a single document.

## Chapters

LRFS v1.0 is organized into three normative specification chapters:

-   **[Payload format](https://llmind.org/spec/payload-format/)** — XMP packet structure, RDF layer schema, canonicalization rules, and backward-compatibility for in-file semantic metadata.
-   **[Signing scheme](https://llmind.org/spec/signing-scheme/)** — HMAC-SHA256 and ed25519 per-layer signatures, SHA-256 file checksum, and verification algorithms.
-   **[Conformance](https://llmind.org/spec/conformance/)** — L1/L2/L3 conformance levels for reader/writer implementations, test vectors, and self-reported compliance.

## Reference implementation

The Python CLI at [github.com/dmitryrollins/LLMind](https://github.com/dmitryrollins/LLMind) is the reference implementation. Third-party implementations (e.g., in Rust, Go, or JavaScript) are welcomed and encouraged.

## Implementations

See the [LRFS implementations](https://llmind.org/spec/implementations/) directory for a list of known LRFS-conformant libraries. Third-party implementations are welcome — submit a PR adding a markdown entry to `src/content/implementations/`.

## Namespace

The stable XMP namespace for LRFS v1.x is [https://llmind.org/ns/1.0/](https://llmind.org/ns/1.0/).

## Roadmap

-   Sprint 1: v0.1 stub — scope, namespace reservation
-   Sprint 2 (this page): v1.0 release — full specification, three chapters
-   Sprint 3: Third-party implementation guidance, test vector publication
-   Sprint 4+: arXiv submission, awesome-list entries, independent implementations

## Contact

Feedback: [spec@llmind.org](mailto:spec@llmind.org)

## Related

-   [File enrichment glossary](https://llmind.org/glossary/) — definitions of terms used throughout the specification