Add frontmatter tools, append, delete + pyyaml dep

requirements.txt

@@ -1 +1,2 @@
 fastmcp>=2.0.0
+pyyaml>=6.0

server.py

@@ -15,6 +15,7 @@ from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any
 
+import yaml
 from fastmcp import FastMCP
 
 # ── Config ────────────────────────────────────────────────────────────────
@@ -599,6 +600,149 @@ def move_document(vault_name: str, src_path: str, dest_path: str) -> dict[str, A
     }
 
 
+@mcp.tool()
+def read_frontmatter(vault_name: str, doc_path: str, key: str | None = None) -> dict[str, Any]:
+    """Read YAML frontmatter from a markdown document.
+
+    Args:
+        vault_name: Name of the vault.
+        doc_path: Relative path to the document.
+        key: Optional specific key to read. If None, returns all frontmatter.
+
+    Returns the frontmatter dict or specific key value.
+    """
+    target = _resolve_doc(vault_name, doc_path)
+    if not target.exists():
+        return {"error": f"Document not found: {doc_path}", "vault": vault_name}
+
+    content = target.read_text(encoding="utf-8", errors="replace")
+    fm = _parse_frontmatter(content)
+    if fm is None:
+        return {"vault": vault_name, "path": doc_path, "frontmatter": {}, "note": "No frontmatter found"}
+
+    if key:
+        return {"vault": vault_name, "path": doc_path, "key": key, "value": fm.get(key)}
+    return {"vault": vault_name, "path": doc_path, "frontmatter": fm}
+
+
+@mcp.tool()
+def write_frontmatter(vault_name: str, doc_path: str, key: str, value: Any = None) -> dict[str, Any]:
+    """Set a YAML frontmatter key on a markdown document. Creates frontmatter if absent.
+
+    Args:
+        vault_name: Name of the vault.
+        doc_path: Relative path to the document.
+        key: Frontmatter key to set.
+        value: Value to set (string, number, boolean, list, or dict). Pass null/None to delete.
+
+    Returns the updated frontmatter state.
+    """
+    target = _resolve_doc(vault_name, doc_path)
+    if not target.exists():
+        return {"error": f"Document not found: {doc_path}", "vault": vault_name}
+
+    content = target.read_text(encoding="utf-8", errors="replace")
+    fm = _parse_frontmatter(content)
+
+    if fm is None:
+        # No frontmatter — create one
+        if value is None:
+            return {"vault": vault_name, "path": doc_path, "action": "noop", "note": "No frontmatter to delete from"}
+        new_fm = {key: value}
+        new_content = "---\n" + yaml.dump(new_fm, default_flow_style=False, allow_unicode=True).strip() + "\n---\n\n" + content
+        target.write_text(new_content, encoding="utf-8")
+        return {"vault": vault_name, "path": doc_path, "key": key, "value": value, "action": "created"}
+
+    # Existing frontmatter
+    if value is None:
+        fm.pop(key, None)
+        action = "deleted"
+    else:
+        fm[key] = value
+        action = "set"
+
+    new_fm_block = "---\n" + yaml.dump(fm, default_flow_style=False, allow_unicode=True).strip() + "\n---"
+    body = _body_after_frontmatter(content)
+    target.write_text(new_fm_block + "\n\n" + body, encoding="utf-8")
+
+    return {"vault": vault_name, "path": doc_path, "key": key, "value": value, "action": action}
+
+
+@mcp.tool()
+def append_to_document(vault_name: str, doc_path: str, content: str) -> dict[str, Any]:
+    """Append content to the end of a markdown document. Creates the file if it doesn't exist.
+
+    Args:
+        vault_name: Name of the vault.
+        doc_path: Relative path to the document.
+        content: Markdown content to append.
+
+    Returns the updated document info.
+    """
+    if not doc_path.lower().endswith(".md"):
+        doc_path = doc_path.rstrip("/\\") + ".md"
+
+    target = _resolve_doc(vault_name, doc_path)
+
+    if not target.exists():
+        target.parent.mkdir(parents=True, exist_ok=True)
+        target.write_text(content + "\n", encoding="utf-8")
+        action = "created"
+    else:
+        existing = target.read_text(encoding="utf-8", errors="replace")
+        separator = "\n" if existing.endswith("\n") else "\n\n"
+        target.write_text(existing + separator + content + "\n", encoding="utf-8")
+        action = "appended"
+
+    return {
+        "vault": vault_name,
+        "path": doc_path.lstrip("/\\").replace("\\", "/"),
+        "action": action,
+        "size_bytes": target.stat().st_size,
+    }
+
+
+@mcp.tool()
+def delete_document(vault_name: str, doc_path: str) -> dict[str, Any]:
+    """Delete a document from a vault.
+
+    Args:
+        vault_name: Name of the vault.
+        doc_path: Relative path to the document.
+
+    Returns deletion confirmation.
+    """
+    target = _resolve_doc(vault_name, doc_path)
+    if not target.exists():
+        return {"error": f"Document not found: {doc_path}", "vault": vault_name}
+
+    target.unlink()
+    return {"vault": vault_name, "path": doc_path.lstrip("/\\").replace("\\", "/"), "action": "deleted"}
+
+
+def _parse_frontmatter(content: str) -> dict[str, Any] | None:
+    """Parse YAML frontmatter from markdown content. Returns None if not found."""
+    if not content.startswith("---"):
+        return None
+    parts = content.split("---", 2)
+    if len(parts) < 3:
+        return None
+    try:
+        return yaml.safe_load(parts[1]) or {}
+    except yaml.YAMLError:
+        return None
+
+
+def _body_after_frontmatter(content: str) -> str:
+    """Return the body content after YAML frontmatter."""
+    if not content.startswith("---"):
+        return content
+    parts = content.split("---", 2)
+    if len(parts) < 3:
+        return content
+    return parts[2].lstrip("\n")
+
+
 # ── Entrypoint ────────────────────────────────────────────────────────────
 
 def main():