Cairn

Anthropic prompt caching for tool schemas and sessions

NousResearch/hermes-agent · cluster 20880 · agent

Data as of

Nothing open on GitHub. Fix merged in #76032. Check it covers your case.

The short answer

0open issues
0open PRs
5items grouped
Known?
Yes. 5 related items grouped here, 1 issue already closed.
Fix event
A fix was merged to main in PR #76032. Check it covers your case. No release data is tracked.
Tracker
The maintainers' tracker marks this resolved, deciding PR #76032. That is separate from the fix event.
Still open
Nothing open on GitHub.

These items address caching of tool schemas and system prompts on Anthropic, including cross-session prefix caching, cache_control budget enforcement, and reducing input-token overhead for tool-heavy agents.

Open issues0

No open issues.

Open PRs0

No open pull requests.

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

  • #76032 perf(prompt-caching): cache tool schemas on native Anthropic without history loss

    merged to main

    files: agent/agent_runtime_helpers.py, agent/auxiliary_client.py, agent/chat_completion_helpers.py, agent/conversation_loop.py, agent/moa_loop.py, agent/prompt_caching.py, run_agent.py, tests/agent/test_auxiliary_client.py, tests/agent/test_failover_identity.py, tests/agent/test_moa_aggregator_cache_control.py, tests/agent/test_prompt_caching.py, tests/run_agent/test_anthropic_prompt_cache_policy.py, tests/run_agent/test_run_agent.py

3 PRs closed without merging

From the close comments: superseded by another PR 2 · merged via another change 1

  • #27170 fix: enforce Anthropic cache_control budget · superseded by another PR → #76032, #37611, #20880
  • #37611 perf(prompt-caching): cache tool schemas without history loss · merged via another change → 9fc12bf, #76032, #20880
  • #69633 fix(agent): support stable cross-session prefix caching on Anthropic · superseded by another PR → #69704
Closed issues · 1
  • Closed#20880Tool-heavy agents pay ~70% input-token overhead — `system_and_3` caching skips tools schema
How this cluster was grouped
  • Link evidence (structural links throughout): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
  • Pairwise link density 0.40: the share of item pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. 1.00 means every pair is linked.

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At a glance

Subsystem
agent
Merged PRs
#76032
Closed issues
1
Attempts
3 PRs closed without merging
Fix link checked
1 Aug 2026

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