PR #16: fix(memory): suppress built-in memory block when external provider is active (#28796)

• Repository: na-navi/hermes-agent
• Author: na-navi
• State: open | merged: False
• Link: https://github.com/na-navi/hermes-agent/pull/16

Description (problem / solution / changelog)

🟢 Merge order: 5 / 12 — small, conditional skip, low risk

Closes #28796 (P3)

Problem

Both built-in MEMORY.md and the external provider's system_prompt_block() were injected into every system prompt, causing duplicate context.

Fix

Auto-suppress the built-in memory block when _memory_manager is active. USER.md (identity) is still included regardless.

Risk assessment

Files changed

• agent/system_prompt.py (+6/-1)

Changed files

• agent/system_prompt.py (modified, +6/-1)

PR #29020: feat(memory): add memory.suppress_builtin_when_external opt-in

• Repository: NousResearch/hermes-agent
• Author: haran2001
• State: open | merged: False
• Link: https://github.com/NousResearch/hermes-agent/pull/29020

Description (problem / solution / changelog)

Summary

Opt-in config knob to stop double-injecting MEMORY.md/USER.md into the system prompt when an external memory provider (OpenViking, Honcho, etc.) is configured and already supplies its own context block.

Before this change, agent/system_prompt.py unconditionally appended both the built-in memory/user blocks and MemoryManager.build_system_prompt(). Users who migrated their notes into an external provider saw the same information twice on every turn and the only workaround was manually flipping memory_enabled: false (which also disables the memory tool).

Behavior

memory:
  provider: openviking
  suppress_builtin_when_external: true   # new, default false

• Flag false / absent → historical additive behavior, byte-stable for existing deployments.
• Flag true + external provider returns non-empty block → built-in memory/user blocks are skipped, external block is injected.
• Flag true + external provider returns empty (no content yet, transient error, exception) → built-in blocks are still injected. We never silently strip the user's notes.

External-provider exceptions are caught and treated as "empty block", same as the prior behavior.

Files

• agent/system_prompt.py — build the external block first, gate the built-in injection on (_suppress && _ext_mem_block).
• agent/agent_init.py — read memory.suppress_builtin_when_external from config, default False, expose as agent._memory_suppress_builtin_when_external.
• tests/agent/test_system_prompt_memory_suppression.py — 5 cases (default keeps both, suppress drops built-in, empty external keeps built-in, no manager configured, external raises).
• website/docs/user-guide/features/memory.md — document the new knob and the "we don't silently strip" safety.

Test Plan

• python -m pytest tests/agent/test_system_prompt_memory_suppression.py -q -o 'addopts=' → 5 passed
• python -m pytest tests/agent/test_memory_provider.py tests/run_agent/test_memory_provider_init.py tests/agent/test_system_prompt_restore.py tests/agent/test_system_prompt_memory_suppression.py -q -o 'addopts=' → 78 passed in 98s

Closes #28796

Changed files

• agent/agent_init.py (modified, +4/-0)
• agent/system_prompt.py (modified, +21/-9)
• tests/agent/test_system_prompt_memory_suppression.py (added, +124/-0)
• website/docs/user-guide/features/memory.md (modified, +11/-1)