write_file
Write content to a file. Creates the file if it doesn't exist, overwrites if it does.
This record as markdown: /tools/deep-ai-kr-dev-mcp/write-file.md
What write_file does on Dev
AI agents use write_file to create or update resources in Dev, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Dev environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
path | string | — | Path to the file to write (relative to root) |
content | string | — | Content to write to the file |
Parameters from the server's own tool schema.
Why write_file is rated Medium
The tool modifies data reversibly by creating or overwriting files. It is not destructive in the sense that the operation is reversible (files can be re-written or restored), and it does not delete data.
From the tool's definition Tool description states 'Write content to a file. Creates the file if it doesn't exist, overwrites if it does.' This is explicitly a write/create/overwrite operation on files.
Risk signalsAccepts file system path (path) · Accepts raw HTML/template content (content)
Attacks that exploit this kind of access
The rule that runs write_file safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Dev, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For write_file, this is the rule to start with:
write_file 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.
The button opens the PolicyLayer dashboard: create your workspace, connect Dev, apply this rule, and every write_file call is checked against it from then on.
Questions about write_file
Write content to a file. Creates the file if it doesn't exist, overwrites if it does. It is categorised as a Write tool in the Dev MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
write_file accepts 2 parameters: path, content. The full parameter table on this page comes from the server's own tool schema.
Register the Dev MCP server in PolicyLayer and add a rule for write_file: 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 Dev. Nothing to install.
write_file 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 write_file 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 write_file. 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.
write_file is provided by the Dev MCP server (deep-ai-kr/dev-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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