NousResearch/hermes-agent

Agent cache prefix stability and tool refresh fixes

Cluster 100336. Data as of 2026-10-24 04:06 UTC

Nothing open on GitHub. Fix merged in #101367 on 2 Sep 2026. Check it covers your case.

open issues

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items grouped

Known?: Yes. 4 related items grouped here, 1 issue already closed.
Fix event: A fix was merged to main in PR #101367. Check it covers your case. No release data is tracked.
Tracker: The maintainers' tracker marks this unresolved. That is separate from the fix event.
Still open: Nothing open on GitHub.

Next step: read #101367, then check it covers your case.

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These items address bugs where the cached system-prompt prefix or tool list was being invalidated or reset during a session—specifically across model switches, agent-cache evictions, and between-turn tool refreshes. The work focuses on preserving prefix-cache state to maintain high cache-hit rates.

Open issues0

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No open pull requests.

Fixes on record

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

#101367 fix(tools): tools[] stays frozen for the session — prefix preserved, survives agent-cache eviction, /reload-mcp re-probes (salvage #100638)

merged to main

files: agent/conversation_loop.py, agent/turn_context.py, cli.py, gateway/run.py, hermes_state.py, hermes_state_common.py, tests/tools/test_refresh_agent_mcp_tools.py, tools/mcp_tool.py, tui_gateway/methods_tools.py, website/docs/reference/slash-commands.md, website/docs/user-guide/features/mcp.md

2 PRs closed without merging

From the close comments: merged via another change 1 · other 1

#100358 fix(agent): keep stored prompt prefix across a mid-session /model switch · other → #100336, #48173, #52666
#100638 fix(agent): stop the between-turns tool refresh from forking the cached prefix (#100336 defect b) · merged via another change → #101367, #100336

Closed issues · 1

Closed#100336Prefix-cache invalidation on model switch: stored system prompt is nulled, forcing full re-prefill of entire history (2% -> 99% cache hit measured)

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At a glance

Merged PRs: #101367
Closed issues: 1
Attempts: 2 PRs closed without merging
Fix link checked: 2 Sep 2026

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