write_file
Write content to a file. Creates parent directories if needed.
This record as markdown: /tools/io-github-kivanccakmak-yaver/write-file.md
What write_file does on Yaver
AI agents use write_file to create or update resources in Yaver, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Yaver environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
path | string | Yes | File path |
content | string | Yes | File content |
Parameters from the server's own tool schema.
Why write_file is rated Medium
This tool creates or modifies files reversibly, which is the definition of Write category. Severity is high because uncontrolled file writes in a development environment could overwrite critical configuration, source code, or build artifacts, potentially causing significant local disruption.
From the tool's definition Tool name is 'write_file' and description states 'Write content to a file. Creates parent directories if needed.' This directly modifies or creates files on the system.
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 Yaver, 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 Yaver, 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 parent directories if needed. It is categorised as a Write tool in the Yaver MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
write_file accepts 2 parameters: path, content. Required: path, content. The full parameter table on this page comes from the server's own tool schema.
Register the Yaver 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 Yaver. 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 Yaver MCP server (yaver-cli). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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