Summary
The Managed Agents API (Sessions API) automatically applies prompt caching server-side, but there is no client-side option to disable it. This results in cache_creation_input_tokens charges that users cannot opt out of.
Current behavior
SessionCreateParams has no caching-related parameters- The Messages API provides
cache_control as an opt-in mechanism, giving users full control
- The Managed Agents harness applies caching automatically with no way to disable it
Expected behavior
A parameter (e.g., disable_prompt_caching: true in SessionCreateParams, or an equivalent header) to opt out of automatic prompt caching in Managed Agents sessions.
Motivation
Cache write tokens cost 1.25x standard input tokens. For use cases where sessions are short-lived or prompts rarely repeat, automatic caching increases cost without benefit. Users should be able to opt out, just as they can choose not to use cache_control in the Messages API.
Environment
- SDK version:
@anthropic-ai/sdk 0.89.0
- Beta:
managed-agents-2026-04-01
Summary
The Managed Agents API (Sessions API) automatically applies prompt caching server-side, but there is no client-side option to disable it. This results in
cache_creation_input_tokenscharges that users cannot opt out of.Current behavior
SessionCreateParamshas no caching-related parameterscache_controlas an opt-in mechanism, giving users full controlExpected behavior
A parameter (e.g.,
disable_prompt_caching: trueinSessionCreateParams, or an equivalent header) to opt out of automatic prompt caching in Managed Agents sessions.Motivation
Cache write tokens cost 1.25x standard input tokens. For use cases where sessions are short-lived or prompts rarely repeat, automatic caching increases cost without benefit. Users should be able to opt out, just as they can choose not to use
cache_controlin the Messages API.Environment
@anthropic-ai/sdk0.89.0managed-agents-2026-04-01