Update existing memory (partial update supported).
AI agents use update_memory to create or update resources in Code Graph Knowledge System — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Code Graph Knowledge System environment.
This tool modifies existing memory records within the Neo4j knowledge graph. While updates are reversible (can be undone or corrected), they alter stored state. The 'partial update' support suggests surgical modifications rather than wholesale replacement.
From the tool's definition Tool name 'update_memory' and description 'Update existing memory (partial update supported)' indicate modification of existing data in the knowledge graph. The partial update capability confirms reversible write operations rather than destructive actions.
Documented attack patterns abuse exactly the kind of access update_memory gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Code Graph Knowledge System, and nothing reaches the server without passing your rules. This is the rule we recommend for update_memory:
{
"version": "1",
"default": "deny",
"tools": {
"update_memory": {
"limits": [
{
"counter": "update_memory_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_memory 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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Update existing memory (partial update supported). It is categorised as a Write tool in the Code Graph Knowledge System MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Code Graph Knowledge System MCP server in PolicyLayer and add a rule for update_memory: 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 Code Graph Knowledge System. Nothing to install.
update_memory 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 update_memory 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 update_memory. 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.
update_memory is provided by the Code Graph Knowledge System MCP server (royisme/codebase-rag). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Code Graph Knowledge System, 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.
30 Code Graph Knowledge System tools catalogued and risk-classified — across an index of 43,000+ MCP servers.