companion_up
Arm the companion manifest (yaver.companion.yaml) at repo: schedule HTTP crons on the in-process scheduler and start/instal durable workers as OS units. Idempotent. Reboot-durable.
This record as markdown: /tools/io-github-kivanccakmak-yaver/companion-up.md
What companion_up does on Yaver
AI agents invoke companion_up to trigger actions in Yaver. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
| Parameter | Type | Required | Description |
|---|---|---|---|
repo | string | Yes | Absolute path to the serverless project repo |
Parameters from the server's own tool schema.
Why companion_up is rated High
This tool executes code/operations by starting workers and scheduling HTTP cron jobs. While not destructive on its own (it is idempotent and can be reversed via companion_down), it performs active execution with persistent side effects (workers as OS units, scheduled tasks).
From the tool's definition The tool description states it will 'schedule HTTP crons on the in-process scheduler and start/install durable workers as OS units.' These are external operations whose effects depend on the manifest configuration and arguments.
Attacks that exploit this kind of access
The rule that runs companion_up safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Yaver, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For companion_up, this is the rule to start with:
companion_up stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Yaver, apply this rule, and every companion_up call is checked against it from then on.
Questions about companion_up
Arm the companion manifest (yaver.companion.yaml) at repo: schedule HTTP crons on the in-process scheduler and start/instal durable workers as OS units. Idempotent. Reboot-durable. It is categorised as a Execute tool in the Yaver MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
companion_up accepts 1 parameter: repo. Required: repo. The full parameter table on this page comes from the server's own tool schema.
Register the Yaver MCP server in PolicyLayer and add a rule for companion_up: 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.
companion_up is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the companion_up 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 companion_up. 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.
companion_up 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.
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