Local customizations: vault injection (Layer 3) preserved after upstream update

agent/vault_injection.py

@@ -0,0 +1,117 @@
+"""Vault injection — auto-load Obsidian vault files into the system prompt.
+
+Reads working-context.md and user-profile.md from a configured vault path
+at session start and injects them into the system prompt alongside Layer 1
+memory (MEMORY.md / USER.md). This is a structural fix for vault neglect:
+the agent no longer needs to remember to read these files — they're injected
+automatically, the same way Layer 1 memory is.
+
+The vault is Layer 3 in the memory architecture. Files injected here are
+read-only in the system prompt (frozen at session start). Mid-session
+writes to vault files require the read_file/write_file tools or the
+memory-vault skill.
+
+Config (in config.yaml under 'vault'):
+  enabled: true          # enable vault injection
+  path: /path/to/vault   # absolute path to the Obsidian vault root
+
+Files read (relative to vault path):
+  Agent-Hermes/working-context.md   — what the agent is actively doing
+  Agent-Shared/user-profile.md      — who the user is (durable facts)
+
+If either file doesn't exist or is empty, it's silently skipped.
+If the vault path doesn't exist or isn't configured, vault injection is
+silently disabled.
+"""
+
+import logging
+import os
+from pathlib import Path
+from typing import Optional
+
+logger = logging.getLogger(__name__)
+
+# Character limits for vault injection blocks (to prevent prompt bloat)
+WORKING_CONTEXT_CHAR_LIMIT = 4000
+USER_PROFILE_CHAR_LIMIT = 4000
+
+SEPARATOR = "\u2550" * 46  # ═ same as memory_tool uses
+
+
+def _read_vault_file(path: Path, char_limit: int) -> Optional[str]:
+    """Read a vault file and return its content, or None if missing/empty.
+
+    Truncates with a notice if the file exceeds char_limit.
+    """
+    if not path.exists():
+        return None
+    try:
+        content = path.read_text(encoding="utf-8").strip()
+    except (OSError, IOError) as e:
+        logger.debug("Could not read vault file %s: %s", path, e)
+        return None
+
+    if not content:
+        return None
+
+    # Strip YAML frontmatter (same as prompt_builder does for context files)
+    content = _strip_yaml_frontmatter(content)
+
+    if not content:
+        return None
+
+    if len(content) > char_limit:
+        truncated = content[:char_limit]
+        # Find last newline to avoid cutting mid-line
+        last_nl = truncated.rfind("\n")
+        if last_nl > char_limit // 2:
+            truncated = truncated[:last_nl]
+        content = truncated + f"\n[... truncated at {char_limit} chars ...]"
+
+    return content
+
+
+def _strip_yaml_frontmatter(content: str) -> str:
+    """Remove optional YAML frontmatter (--- delimited) from content."""
+    if content.startswith("---"):
+        end = content.find("\n---", 3)
+        if end != -1:
+            body = content[end + 4:].lstrip("\n")
+            return body if body else content
+    return content
+
+
+def build_vault_system_prompt(vault_path: str) -> str:
+    """Build the vault injection block for the system prompt.
+
+    Reads working-context.md and user-profile.md from the vault and formats
+    them with headers matching the style of Layer 1 memory blocks.
+
+    Returns an empty string if vault is disabled, path is missing, or
+    all files are empty.
+    """
+    if not vault_path:
+        return ""
+
+    vault_root = Path(vault_path)
+    if not vault_root.is_dir():
+        logger.debug("Vault path does not exist or is not a directory: %s", vault_path)
+        return ""
+
+    parts = []
+
+    # Read working-context.md (agent's current state)
+    wc_path = vault_root / "Agent-Hermes" / "working-context.md"
+    wc_content = _read_vault_file(wc_path, WORKING_CONTEXT_CHAR_LIMIT)
+    if wc_content:
+        header = "VAULT: WORKING CONTEXT (what you're doing right now)"
+        parts.append(f"{SEPARATOR}\n{header}\n{SEPARATOR}\n{wc_content}")
+
+    # Read user-profile.md (shared user profile)
+    up_path = vault_root / "Agent-Shared" / "user-profile.md"
+    up_content = _read_vault_file(up_path, USER_PROFILE_CHAR_LIMIT)
+    if up_content:
+        header = "VAULT: USER PROFILE (durable facts from Obsidian vault)"
+        parts.append(f"{SEPARATOR}\n{header}\n{SEPARATOR}\n{up_content}")
+
+    return "\n\n".join(parts)