db_migrate · Yaver MCP: Risk & Policy

WHAT IT DOES

What db_migrate does on Yaver

AI agents use db_migrate 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.

PARAMETERS

Parameter	Type	Required	Description
`target`	string	—	Target: local or production (default: local)

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why db_migrate needs a policy

An AI agent can call db_migrate faster than any human can review — one bad instruction and it creates or modifies resources in Yaver by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

db_migrate Rate-limited

db_migrate 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "db_migrate": {
      "limits": [
        {
          "counter": "db_migrate_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Yaver, so you can run agents against it safely.

FAQ

Questions about db_migrate

What does the db_migrate tool do? +

Run pending database migrations. Auto-detects ORM (Drizzle, Prisma, Goose, Alembic). 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.

What parameters does db_migrate accept? +

db_migrate accepts 1 parameter: target. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on db_migrate? +

Register the Yaver MCP server in PolicyLayer and add a rule for db_migrate: 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.

What risk level is db_migrate? +

db_migrate is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit db_migrate? +

Yes. Add a rate_limit block to the db_migrate 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.

How do I block db_migrate completely? +

Set action: deny in the PolicyLayer policy for db_migrate. 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.

What MCP server provides db_migrate? +

db_migrate 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.