GPAI Ledger › Mythos 5.1 / Fable 5.1 (Anthropic)
Mythos 5.1 / Fable 5.1
Public summary of training content · Article 53(1)(d), Regulation (EU) 2024/1689
Provider: Anthropic — status: Published
Anthropic publishes a public summary of training content for Mythos 5.1 / Fable 5.1 under the EU AI Act; every version this ledger has captured is archived below with its hash and timestamp proof.
AIAL metadata: summary dated 2026-09-01, model released 2026-09-01, eval page
Document versions
| Capture (UTC) | Source of copy | URL | SHA-256 | Bytes | Notes |
|---|---|---|---|---|---|
| 20260913T114722Z | AIAL archived copy | aial.ie/research/gpai-training-transpare…able_Mythos_5_1_2026_09_08.pdf | ff3ed62ab5d93f58… | 293,261 |
Watch-surface captures
Captures of the page(s) where the document is published (portals, hubs, docs pages) — monitored for change detection; not the document itself.
| Capture (UTC) | Source of copy | URL | SHA-256 | Bytes | Notes |
|---|---|---|---|---|---|
| 20261012T134311Z | provider site | trust.anthropic.com/resources | 0faf3ab6c6c0e6f8… | 278,718 | rendered page (captured with a browser); page text changed vs the previous capture of this target (44 word(s) differ in the extracted text) |
| 20261008T122519Z | provider site | trust.anthropic.com/resources | 611908435061a2d3… | 271,496 | rendered page (captured with a browser); page text changed vs the previous capture of this target (19 word(s) differ in the extracted text) |
| 20261007T120944Z | provider site | trust.anthropic.com/resources | e783e8dc0cf7d121… | 268,334 | rendered page (captured with a browser); page text changed vs the previous capture of this target (70 word(s) differ in the extracted text) |
| 20261006T122002Z | provider site | trust.anthropic.com/resources | d1383f12f8d5299f… | 261,968 | rendered page (captured with a browser); page text changed vs the previous capture of this target (32 word(s) differ in the extracted text) |
| 20260930T112852Z | provider site | trust.anthropic.com/resources | 2d0cb0f33301a748… | 258,532 | rendered page (captured with a browser); page text changed vs the previous capture of this target (16 word(s) differ in the extracted text) |
| 20260929T114118Z | provider site | trust.anthropic.com/resources | eba317748274eb6f… | 258,172 | rendered page (captured with a browser); page text changed vs the previous capture of this target (54 word(s) differ in the extracted text) |
| 20260924T103826Z | provider site | trust.anthropic.com/resources | 37b7597fdc56473c… | 251,991 | rendered page (captured with a browser); page text changed vs the previous capture of this target (30 word(s) differ in the extracted text) |
| 20260923T102506Z | provider site | trust.anthropic.com/resources | ce514a80ab7ca363… | 248,586 | rendered page (captured with a browser); page text changed vs the previous capture of this target (44 word(s) differ in the extracted text) |
| 20260918T060237Z | provider site | trust.anthropic.com/resources | 239bb4b36921aa97… | 242,509 | rendered page (captured with a browser); page text changed vs the previous capture of this target (32 word(s) differ in the extracted text) |
| 20260913T114644Z | provider site | trust.anthropic.com/resources | f41756d3de9092e2… | 238,732 | rendered page (captured with a browser) |
Third-party evaluation
The AI Accountability Lab scores published summaries against the Commission's template and publishes the result. These are captures of their assessment, archived here because they are revised over time and a score is otherwise unrecoverable once changed. It is AIAL's research judgement, not a legal determination, and not the provider's document. Their assessment is archived here but not served on this site or in the dataset: each capture below proves what was published and when, and points to AIAL for the content. Attribution: aial.ie.
| Capture (UTC) | Source of copy | URL | SHA-256 | Bytes | Notes |
|---|---|---|---|---|---|
| 20260913T125648Z | AIAL evaluation (earlier state) | raw.githubusercontent.com/AIAccountabili…evals/anthropic-mythos5.1.yaml | cbdb426c25f4ec5e… | 3,188 | the state that stood upstream from 10 Sep 2026 (fetched here on 13 Sep 2026); bytes identical to 20260913T114727Z |
| 20260913T114735Z | AIAL evaluation page | aial.ie/research/gpai-training-transparency/evals/anthropic-mythos5.1/ | abdb14d358b9c095… | 19,957 | |
| 20260913T114727Z | AIAL evaluation | raw.githubusercontent.com/AIAccountabili…evals/anthropic-mythos5.1.yaml | cbdb426c25f4ec5e… | 3,188 |
Last checked: 2026-10-12 (re-checked on the daily schedule — see Methodology). Seen a summary we missed? See the contact details.