PatternsAgent Patterns

Anthropic Cache Control (AI Gateway)

Lightweight ToolLoopAgent pattern for Anthropic ephemeral cache control through Vercel AI Gateway: cached system instructions with cacheControl and reports cache read/write tokens.

Loading preview…

Problems solved

Technical challenges this implementation handles out of the box.

Set Anthropic ephemeral cacheControl breakpoints via AI Gateway
Cache long system instructions on a ToolLoopAgent
Measure cache creation versus cache read tokens per turn

Use cases

Products and workflows this pattern is designed to support.

Explicit ephemeral caching for long agent policies
Multi-turn agents with stable system prefixes
Teaching Anthropic cache read versus write metrics

Setup

Requirements, wiring steps, and what this pattern adds to your project.

Getting started

Pick how you want to pull this pattern in — then wire env vars and routes the same way.

1
Install from the preview toolbar
Copy the install command above and run it in your project — Pro patterns include a short-lived token.
2
Add environment variables to .env.local
AI_GATEWAY_API_KEY
3
Point client fetches at your API routes
Replace preview `/view/.../api/...` paths with `/api/...` in the installed files.
4
Customize the agent and tool files
Adapt prompts, tools, and stop conditions for your product — Copy for AI in the toolbar helps seed that work.
5
Run your dev server and open the pattern route
Install dependencies if needed, then start the app and verify responses.

Environment variables

AI_GATEWAY_API_KEYGet key

Capabilities

AI SDK APIs

ToolLoopAgentgatewayproviderOptionsinstructionsstepCountIs

Providers

anthropic

Files added

9 files

app/page.tsx
app/layout.tsx
app/api/cache-anthropic/route.ts
lib/cache-anthropic-agent.ts
lib/build-cached-instructions.ts
lib/cache-metrics.ts
lib/stable-system-prompt.ts
lib/request-utils.ts
README.md

Dependencies

9 total

npm packages

AISDKlucide-reactNext.jsReactZod

Registry components

alertbadgebuttonskeleton

Critical files

lib/build-cached-instructions.ts
Builds SystemModelMessage instructions with providerOptions.anthropic.cacheControl ephemeral breakpoint.
lib/cache-anthropic-agent.ts
ToolLoopAgent uses buildAnthropicCachedInstructions() as instructions (not messages).