Write text to a file under PROJECT_ROOT (creates dirs if needed)
AI agents use project_write_file to create or update resources in 8th Wall MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your 8th Wall MCP Server environment.
This tool creates or modifies files reversibly within a project directory structure. It does not delete data (Destructive) nor execute arbitrary code (Execute). The blast radius is moderate because an agent could overwrite project files, corrupt the WebAR project state, or pollute the filesystem with unwanted files, but changes remain reversible through normal file operations.
From the tool's definition Tool name contains 'write' and description states 'Write text to a file'. The phrase 'creates dirs if needed' indicates it modifies the filesystem by creating files and directories.
Documented attack patterns abuse exactly the kind of access project_write_file gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and 8th Wall MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for project_write_file:
{
"version": "1",
"default": "deny",
"tools": {
"project_write_file": {
"limits": [
{
"counter": "project_write_file_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}project_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.
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Write text to a file under PROJECT_ROOT (creates dirs if needed). It is categorised as a Write tool in the 8th Wall MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the 8th Wall MCP Server MCP server in PolicyLayer and add a rule for project_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 8th Wall MCP Server. Nothing to install.
project_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 project_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 project_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.
project_write_file is provided by the 8th Wall MCP Server MCP server (superdwayne/8thwallmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from 8th Wall MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
64 8th Wall MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.