Official prompt history

Claude system prompt

Anthropic's January 18 Claude Opus 4.5 entry expands product context and makes the boundary around potentially changed product details more explicit.

Limited excerpt and analysis Claude Opus 4.5 · January 18, 2026

Publication context

Read the provenance first

The official prompt is publicly viewable; this route publishes one short excerpt plus original normalization and interpretation.

Source tier: Tier A · vendor-published
Confidence: high
Published: Jan 18, 2026
Completeness: partial
Checksum: sha256:a86dd6e26d096…
Raw artifact: Not publicly reproduced

The reader presents source-led semantic normalization; the selected January record also includes one short official excerpt. It does not mirror the full Anthropic publication.

Product information boundary

editorial normalization

Editorial normalization:
The January update keeps Claude Opus 4.5 identity and expands named product context to browser, spreadsheet, and desktop task surfaces alongside chat, API, and Claude Code.

Reading note. Anthropic marks the additional product context as changed in the official dated publication.

Knowledge and support routing

verbatim excerpt

Official limited excerpt:
“Claude does not know other details about Anthropic's products.”

Editorial normalization:
The update explicitly treats unlisted product details as potentially changed and routes users to official support or developer documentation.

Reading note. The short excerpt is presented with the broader source-led meaning and does not imply access to live product state.

Response conventions

source led map

Source-led map:
The official publication describes prompt-level response shaping, including current-date context and formatting expectations.

Reading note. This section records the function of the published system prompt without reproducing its full text.

Evidence and provenance

Tier A · vendor-published: Anthropic system-prompt release publication — Vendor-published prompt material supports a Tier A record; full-text republication is intentionally avoided.

Snapshot evidence

What this snapshot includes and leaves out.

Product surface: claude.ai and Claude apps
Model context: Claude Opus 4.5This record selects the model's two official dated entries to demonstrate compatible version history; it is not a claim about every Claude model.
Checksum scope: Three-section limited excerpt and editorial normalization of the official dated entry; UTF-8, LF line endings.
Raw mode: Use Anthropic's official dated publication for the full text. Promptcred retains limited excerpts, normalization, checksums, and change interpretation.