{
  "id": "data.file.write.v1",
  "name": "File Write Access Policy",
  "description": "Pre-action governance for file write operations. Enforces path allowlists, blocked paths (system directories, binaries), extension restrictions, size limits, and rate limiting for secure agent file modifications.",
  "version": "1.0.0",
  "status": "active",
  "requires_capabilities": ["data.file.write"],
  "min_assurance": "L0",
  "limits_required": ["allowed_paths"],
  "required_fields": ["file_path"],
  "optional_fields": [
    "content",
    "content_length",
    "encoding",
    "append",
    "create_dirs"
  ],
  "enforcement": {
    "path_allowlist_enforced": true,
    "blocked_paths_enforced": true,
    "extension_restrictions_enforced": true,
    "file_size_enforced": true,
    "rate_limiting_enforced": true
  },
  "mcp": {
    "require_allowlisted_if_present": true
  },
  "advice": [
    "Use path allowlists to restrict file writes to specific directories",
    "Block system directories (/etc, /bin, /usr/bin, /System, C:\\Windows)",
    "Enforce allowed file extensions to prevent malicious file creation",
    "Set file size limits to prevent disk exhaustion attacks",
    "Implement rate limiting (writes per hour) to detect anomalous behavior",
    "Log all file write operations for Verifiable Attestation and rollback",
    "Use working directory restrictions in combination with path allowlists",
    "Monitor write patterns for anomalies (e.g., writing to 100s of files/hour)",
    "Subscribe to status webhooks for instant suspend on suspicious activity",
    "Consider implementing write sandboxing for untrusted agents",
    "Audit logs should capture file path, size, hash, and timestamp"
  ],
  "required_context": {
    "$schema": "http://json-schema.org/draft-07/schema#",
    "type": "object",
    "required": ["file_path"],
    "properties": {
      "file_path": {
        "type": "string",
        "minLength": 1,
        "maxLength": 4096,
        "description": "Absolute or relative file path to write"
      },
      "content": {
        "type": "string",
        "maxLength": 10485760,
        "description": "File content to write (max 10MB)"
      },
      "content_length": {
        "type": "integer",
        "minimum": 0,
        "maximum": 10485760,
        "description": "Content length in bytes (for size validation without transferring full content)"
      },
      "encoding": {
        "type": "string",
        "enum": ["utf-8", "utf-16", "ascii", "base64", "binary"],
        "description": "File encoding (optional, default: utf-8)"
      },
      "append": {
        "type": "boolean",
        "description": "Append to file instead of overwriting (optional, default: false)"
      },
      "create_dirs": {
        "type": "boolean",
        "description": "Create parent directories if they don't exist (optional, default: false)"
      },
      "mcp_servers": {
        "type": "array",
        "items": { "type": "string" },
        "description": "MCP servers being used in this request"
      },
      "mcp_tools": {
        "type": "array",
        "items": { "type": "string" },
        "description": "MCP tools being used in this request"
      },
      "mcp_server": {
        "type": "string",
        "description": "Single MCP server being used (backward compatibility)"
      },
      "mcp_tool": {
        "type": "string",
        "description": "Single MCP tool being used (backward compatibility)"
      },
      "mcp_session": {
        "type": "string",
        "description": "MCP session identifier for audit trail (optional)"
      }
    }
  },
  "evaluation_rules_version": "1.0",
  "evaluation_rules": [
    {
      "name": "path_allowlist",
      "type": "expression",
      "condition": "limits.allowed_paths.includes('*') || limits.allowed_paths.some(p => context.file_path.startsWith(p) || context.file_path.includes(p.replace('*', '')))",
      "deny_code": "oap.path_not_allowed",
      "description": "File path must be in allowed list or match allowed pattern",
      "message": "File path not in allowed list. Configure passport limits.data.file.write.allowed_paths to grant access."
    },
    {
      "name": "blocked_paths",
      "type": "custom_validator",
      "validator": "validateWriteBlockedPaths",
      "deny_code": "oap.path_blocked",
      "description": "File path must not be in blocked list (system directories, binaries)",
      "message": "Writing to system directories or critical files is not allowed."
    },
    {
      "name": "extension_check",
      "type": "custom_validator",
      "validator": "validateWriteFileExtension",
      "deny_code": "oap.extension_not_allowed",
      "description": "File extension must be in allowed list (if configured)",
      "message": "File extension not allowed. Configure passport limits.data.file.write.allowed_extensions to grant access."
    },
    {
      "name": "file_size_limit",
      "type": "custom_validator",
      "validator": "validateFileContentSize",
      "deny_code": "oap.limit_exceeded",
      "description": "File size must not exceed configured limit",
      "message": "File size exceeds configured limit. Reduce content size or increase passport limit."
    },
    {
      "name": "rate_limit",
      "type": "custom_validator",
      "validator": "validateWriteRateLimit",
      "deny_code": "oap.rate_limit_exceeded",
      "description": "Write operations must not exceed rate limit (writes per hour)",
      "message": "Write rate limit exceeded. Too many file writes in the current time window."
    },
    {
      "name": "parent_directory_check",
      "type": "custom_validator",
      "validator": "validateParentDirectory",
      "deny_code": "oap.directory_not_allowed",
      "description": "Parent directory must exist or create_dirs must be allowed",
      "message": "Parent directory does not exist and create_dirs is not allowed."
    }
  ],
  "cache": {
    "default_ttl_seconds": 60,
    "suspend_invalidate_seconds": 30
  },
  "deprecation": null,
  "created_at": "2026-02-21T00:00:00Z",
  "updated_at": "2026-02-21T00:00:00Z"
}