write_file_base64
A write tool on the Mapi Agent Memory MCP server.
This record as markdown: /tools/mapi-agent-memory/write-file-base64.md
What write_file_base64 does on Mapi Agent Memory
AI agents use write_file_base64 to create or update resources in Mapi Agent Memory, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mapi Agent Memory environment.
Why write_file_base64 is rated Medium
This tool creates or modifies files by writing base64-encoded content, which is a reversible Write operation. The lack of descriptive information and base64 encoding (often used to obscure content) prevents confidence from reaching 'critical', but the write capability to a file system poses a medium-to-high risk of data corruption or unauthorized modification if misused by an AI agent.
From the tool's definition Tool name 'write_file_base64' indicates writing data to a file in base64 format. Description is empty, limiting direct evidence, but the name strongly suggests file modification.
Attacks that exploit this kind of access
The rule that runs write_file_base64 safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Mapi Agent Memory, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For write_file_base64, this is the rule to start with:
write_file_base64 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 Mapi Agent Memory, apply this rule, and every write_file_base64 call is checked against it from then on.
Questions about write_file_base64
write_file_base64 is a write tool on the Mapi Agent Memory MCP server. It is categorised as a Write tool in the Mapi Agent Memory MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mapi Agent Memory MCP server in PolicyLayer and add a rule for write_file_base64: 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 Mapi Agent Memory. Nothing to install.
write_file_base64 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_base64 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_base64. 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_base64 is provided by the Mapi Agent Memory MCP server (cabo0m/mapi-agent-memory). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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