Claim · 2025-11 · publication · Stated in source · Supported

Anthropic published the Claude Opus 4.5 system card, dated November 2025 on its cover and revised to December 5, 2025.

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 4.5

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 4.5

Machine-checkedStated in sourceSupported

Supporting evidence: primary · 1 source

Object version: As dated November 2025 on its cover, with changelog entries to December 5, 2025 · Published 2025-11 · Effective date not established · Revised 2025-12-05
Date: 2025-11 · publication Records dated 2025 →

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

The evidence 02

primary sourceSupports the claim

System Card: Claude Opus 4.5

Anthropic · 2025-11

Cite the original source

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

Source excerpt

“System Card: Claude Opus 4.5 November 2025”

Location in source Cover, PDF p. 1

How it was read Retrieved directly from the publisher

Machine-checked · 2026-11-03

Source details and check notes

Authors: Anthropic
Version: Retrieved for the candidate pack on 2026-11-02 (SHA-256 33be92efcb58f901d9d2c17e61bf277afbd514a1ac70a642f21e918c21ca25a8) directly from the publisher’s host. Retrieved again on 2026-11-03 with the same SHA-256.
Version date: 2025-12-05
Canonical address: Open the canonical source ↗
Accessed: 2026-11-02
Language: English (en)
Attribution: Anthropic, “System Card: Claude Opus 4.5”, 2025-11.
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). The quotation (7 words) matched the card’s text retrieved for the candidate pack on 2026-11-02 (SHA-256 33be92efcb58f901d9d2c17e61bf277afbd514a1ac70a642f21e918c21ca25a8) and again on 2026-11-03 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. No human editorial review.

primary sourceSupports the claim

System Card: Claude Opus 4.5

Anthropic · 2025-11

Cite the original source

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

Source excerpt

“November 24, 2025 … November 25, 2025 … December 5, 2025”

Location in source Changelog, PDF p. 2

How it was read Retrieved directly from the publisher

Machine-checked · 2026-11-03

Source details and check notes

Authors: Anthropic
Version: Retrieved for the candidate pack on 2026-11-02 (SHA-256 33be92efcb58f901d9d2c17e61bf277afbd514a1ac70a642f21e918c21ca25a8) directly from the publisher’s host. Retrieved again on 2026-11-03 with the same SHA-256.
Version date: 2025-12-05
Canonical address: Open the canonical source ↗
Accessed: 2026-11-02
Language: English (en)
Attribution: Anthropic, “System Card: Claude Opus 4.5”, 2025-11.
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). The quotation (11 words) matched the card’s text retrieved for the candidate pack on 2026-11-02 (SHA-256 33be92efcb58f901d9d2c17e61bf277afbd514a1ac70a642f21e918c21ca25a8) and again on 2026-11-03 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. Abridged quotation: the ellipsis marks omitted words, so it is not one continuous string. 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 cover date, month precision; no day is given. The changelog's latest revision is dated December 5, 2025.

Record ID mc-anthropic-claude-opus-4-5-card-published