Mastra drops 6-minute prompt caching tutorial

Hot take: this is more valuable as developer education than as a flashy launch, because prompt caching only matters when your prompt structure is disciplined enough to keep prefixes stable.

• –The pitch is straightforward: reuse long shared prefixes to reduce cost and response time.
• –OpenAI’s caching only kicks in for sufficiently long prompts, so this is most relevant for agent apps, memory systems, and other repeated-context workloads.
• –Mastra’s angle is strong because it can make caching easier to apply in real agent pipelines, not just in toy demos.
• –The claimed savings are meaningful, but they depend on workload shape; they are not universal.