Claim · 2025-05 · publication · Stated in source · Supported

Anthropic published the system card for Claude Opus 4 and Claude Sonnet 4, dated May 2025 on its cover.

One recorded claim. The claim panel gives its qualification, the source passages with their place in each source, and how it was checked.

What it connects

Anthropic → published → System Card: Claude Opus 4 & Claude Sonnet 4

Where it appears

No collection page holds this claim. It is listed with its records in the explorer.

Claim and evidence

Anthropicpublished ↓System Card: Claude Opus 4 & Claude Sonnet 4

Machine-checkedStated in sourceSupported

Supporting evidence: primary · 1 source

Object version: As dated May 2025 on its cover · Published 2025-05 · Effective date not established
Date: 2025-05 · publication Records dated 2025 →

Scope and limitsPublication is not evidence that the evaluations described were carried out as described.

The evidence 01

primary sourceSupports the claim

System Card: Claude Opus 4 & Claude Sonnet 4

Anthropic · 2025-05

Cite the original source

Cite the original document, not Selekoa. Check these details against it.

Source excerpt

“May 2025”

Location in source Cover, PDF p. 1

How it was read Retrieved directly from the publisher

Machine-checked · 2026-11-05

Source details and check notes

Authors: Anthropic
Version: Retrieved for the candidate pack on 2026-11-05 (SHA-256 c358464289e24283fc9d5613d2a676fd8aaba510f1449bcedae01a74d8232ab4) directly from the publisher’s host. Retrieved again on 2026-11-05, after the adjudication, with the same SHA-256; the cross-family check of 2026-11-05 retrieved the same SHA-256. The cross-family check of 2026-11-05 located an Internet Archive capture of 2025-07-17 at the same address; it was not retrieved, so it is not recorded as this source's archive copy.
Canonical address: Open the canonical source ↗
Accessed: 2026-11-05
Language: English (en)
Attribution: Anthropic, “System Card: Claude Opus 4 & Claude Sonnet 4”, 2025-05.
Reuse: No open redistribution licence asserted. Bibliographic metadata, editorial paraphrases and short attributed quotations (at most 50 words each). Recheck terms before wider redistribution.
Check notes: Candidate pack passage, model cards compared (research/model-cards-3). The quotation (2 words) matched the card’s text retrieved for the candidate pack on 2026-11-05 (SHA-256 c358464289e24283fc9d5613d2a676fd8aaba510f1449bcedae01a74d8232ab4) and again on 2026-11-05, after the adjudication, in a fresh retrieval with the same SHA-256. Matching ignored differences of whitespace, case, quotation marks, dashes, PDF line-break hyphens and Unicode compatibility forms, so the source’s typography can differ. The pack was prepared by a model of the GPT family (Codex) and checked by a Claude model. No human editorial review.

Status and meaning

Editorial status. Machine-checked. Machines found this record and checked it against its sources; no person accepted it individually. Each evidence record above shows how it was checked.

Relation. Publication of a specific document or version. Publication of a policy is not evidence of implementation.

Date. The month printed on the cover; no day is printed.

Record ID mc-anthropic-claude-4-card-published