Prompt Caching
Claude API · Anthropic
Foundation Model & API — Anthropic (Claude)
Evaluates Anthropic's Prompt Caching across 9 scenario-based test cases, each graded against an expected-behavior rubric by an LLM judge, from Corsac's Foundation Model & API eval coverage.
About Anthropic
Anthropic is an AI safety company and the maker of Claude. Its API exposes the Claude model family (Opus, Sonnet, Haiku) with tool use, prompt caching, extended thinking, batch processing, vision, the Files and Memory tools, and the Claude Agent SDK.
Sample tests· showing 3 of 9
| # | Input | Expected behavior | Check |
|---|---|---|---|
| 01 | Agent reuses a 12k-token system prompt across many requests. First request adds cache_control={type:'ephemeral'} on the system content block. | First request returns usage.cache_creation_input_tokens covering the system block. Subsequent requests within TTL return usage.cache_read_input_tokens for the same span. Verify both counters before claiming cost savings. | Pass / FailAi Platformhigh |
| 02 | Agent attempts 5 cache_control breakpoints: tools, system, messages[0], messages[2], messages[4]. | Per docs the maximum is 4 cache breakpoints in a single request. The 5th breakpoint causes invalid_request_error. Plan breakpoint placement (typically tools, system, and last 2 stable conversation prefixes). | Pass / FailAi Platformmedium |
| 03 | Large tools[] array (40 tools, 8k tokens of schemas) is reused. Place cache_control on the last tool entry. | cache_control on the trailing tool establishes a breakpoint covering the entire tools[] array (and any earlier cached prefix). Subsequent requests with the identical tools[] hit; any reordering or schema mutation invalidates. | Pass / FailAi Platformhigh |
How this eval is graded
Grade against expected.ideal_behavior and expected.rubric. Per-criterion pass requires mean >= 4.0 and no criterion below 3.
Rubric criteria
- Anthropic
- Ai Platform
- Prompt Caching
Recommended for
Works with
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ViewFrequently asked questions
What does the Prompt Caching eval for Anthropic Claude API test?+
Evaluates Anthropic's Prompt Caching across 9 scenario-based test cases, each graded against an expected-behavior rubric by an LLM judge, from Corsac's Foundation Model & API eval coverage.
How is the Prompt Caching eval scored?+
The judge rubric: Grade against expected.ideal_behavior and expected.rubric. Per-criterion pass requires mean >= 4.0 and no criterion below 3.
How many test cases does this eval pack include?+
The Prompt Caching pack for Anthropic Claude API contains 9 test cases. 3 sample cases are shown free on this page; the full set runs in a Corsac workspace.
How do I run this eval?+
Sign up for Corsac, connect your model or agent endpoint, and run the Prompt Caching pack as-is or after customizing thresholds. Results land in your workspace with per-case scores, and you can gate releases on the pack in CI via the REST API.
Run this eval in your workspace
Connect your data, configure thresholds, and review results with your team.