AI agents use FileEdit to create or update resources in Mcp Wcgw — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mcp Wcgw environment.
FileEdit creates or modifies data (file content) reversibly through search/replace operations. It does not delete files (would be Destructive) but edits them, placing it in Write category. Severity is high because an AI agent could modify critical source code, configuration files, or credentials with broad blast radius, though the modifications are theoretically reversible via version control or undo.
From the tool's definition Tool description states 'Edit existing files using search/replace blocks' — this directly modifies file content. The server description emphasizes 'file edit capabilities' and notes it can 'invoke any cli command', indicating broad file system access.
Documented attack patterns abuse exactly the kind of access FileEdit gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Wcgw, and nothing reaches the server without passing your rules. This is the rule we recommend for FileEdit:
{
"version": "1",
"default": "deny",
"tools": {
"FileEdit": {
"limits": [
{
"counter": "fileedit_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}FileEdit stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Edit existing files using search/replace blocks. It is categorised as a Write tool in the Mcp Wcgw MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mcp Wcgw MCP server in PolicyLayer and add a rule for FileEdit: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Mcp Wcgw. Nothing to install.
FileEdit is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the FileEdit rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for FileEdit. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
FileEdit is provided by the Mcp Wcgw MCP server (rusiaaman/wcgw). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Mcp Wcgw tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
7 Mcp Wcgw tools catalogued and risk-classified — across an index of 42,500+ MCP servers.