personal-wiki/references/soul-md-approach-official.md

Raw Source: SOUL.md Introduction & Methods — Approach A (Official / Pragmatic)

Source: https://hermes-agent.nousresearch.com/docs/user-guide/features/personality Source: https://hermes-agent.nousresearch.com/docs/guides/use-soul-with-hermes Type: official documentation (Nous Research / Hermes Agent) Confidence: high (primary source) Date collected: 2026-09-25

Summary

SOUL.md is the agent's primary identity file at ~/.hermes/SOUL.md (or $HERMES_HOME/SOUL.md). It lives at slot #1 of the system prompt — the first text the model sees before any user message. It defines tone, personality, communication style, and how the agent handles uncertainty, disagreement, and ambiguity.

Key rules

• Load path: ONLY from HERMES_HOME (never from cwd).
• Never overwritten by Hermes; starter file auto-seeded if missing.
• Empty/missing file → falls back to built-in default identity.
• Scanned for prompt injection before inclusion; content injected verbatim after truncation.
• Stable identity: durable voice, not project-specific rules.

What goes in SOUL.md (official recommendation)

• Identity / who the agent is
• Style / how it communicates
• Avoid / stylistic prohibitions
• Defaults / behavior under ambiguity

What does NOT go in SOUL.md

• Project conventions → AGENTS.md
• File paths, repo rules → AGENTS.md
• Tool preferences / commands → AGENTS.md or config.yaml
• Memory / user context → MEMORY.md / USER.md