AI agents use link to create or update resources in MegaMemory — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MegaMemory environment.
This tool creates new relationships in a persistent knowledge graph but does not delete data or execute arbitrary code. The effect is reversible (relationships can be removed via 'remove_concept' or modified via subsequent 'link' calls).
From the tool's definition Tool name 'link' combined with description 'Create a relationship between two existing concepts' indicates it creates or modifies data (a relationship graph) reversibly.
Documented attack patterns abuse exactly the kind of access link gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MegaMemory, and nothing reaches the server without passing your rules. This is the rule we recommend for link:
{
"version": "1",
"default": "deny",
"tools": {
"link": {
"limits": [
{
"counter": "link_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}link 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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Create a relationship between two existing concepts. It is categorised as a Write tool in the MegaMemory MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MegaMemory MCP server in PolicyLayer and add a rule for link: 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 MegaMemory. Nothing to install.
link 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 link 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 link. 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.
link is provided by the MegaMemory MCP server (0xk3vin/megamemory). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 9 MegaMemory tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
9 MegaMemory tools catalogued and risk-classified — across an index of 42,500+ MCP servers.