# Perplexity — Prompt caching for presets

- Company: Perplexity (perplexity.ai)
- Announced: 2026-08-19T17:39:11+00:00
- Category: capability-change
- Subject: Sonar
- Source: https://docs.perplexity.ai/docs/resources/changelog#august-2026
- Record: https://forck.live/items/5057-prompt-caching-for-presets

Agent API presets now automatically use stable prompt cache keys, allowing reuse of shared prompt prefix across requests, which can reduce costs by about 5%.

## Evidence

Verbatim from https://docs.perplexity.ai/docs/resources/changelog#august-2026:

> Agent API presets now use stable prompt cache keys automatically, allowing independent requests with the same preset to reuse the shared prompt prefix (system prompt and tool definitions).

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Record: https://forck.live/items/5057-prompt-caching-for-presets
Catalogue: https://forck.live/llms.txt
Feed: https://forck.live/feed.md