Tools, sub-agents, and sandboxes

Runtime tools act inside the sandbox or Hivy. Connections and custom MCP servers add outside tools, while skills provide reusable instructions. Grant only the combination required by the job.

Files and code

Read files, write changes, apply patches, and inspect code.

Shell

Run scripts or commands inside the session sandbox.

Image and web

Create visuals, search the web, or read a specific page.

Orchestration

Manage plans, request input, search sessions, or delegate.

Hivy selects every configurable built-in tool on a new custom agent. Remove the ones this role won't use; if you add a sub-agent, Hivy keeps the delegation tool switched on. Drive transfer tools stay on because they protect useful files from temporary sandbox storage.

An agent receives the connections available to its team, which may expose a connected service or database. Switch off an optional connection on one agent when that role doesn't need it; the team grant remains available to its other agents.

Catalog requirements work differently: Hivy blocks the team installation until every required connection is available, then keeps those required connections on for the installed agent.

Give a sub-agent one bounded specialty and describe when the parent should call it. Its instructions and tool list should cover that assignment, not the parent's whole role.

1. 01

   Separate by expertise

   Create a specialist when a part of the job needs instructions or context that would distract the parent.

2. 02

   Choose its model independently

   Let the sub-agent inherit the parent model unless its assignment has a different cost or capability requirement.

3. 03

   Grant its tools independently

   Parent-only tools don't flow into the sub-agent; it receives the tool list saved on its own configuration.

4. 04

   Keep delegation worth the overhead

   Don't split out work the parent already handles well. A separate run makes sense when the specialist needs a distinct context or can take a self-contained assignment.

Hivy shows each delegated task as a sub-agent card during the session. Open the card to inspect its progress while the parent coordinates the overall task.

Hivy provisions an isolated sandbox when a session starts, using the image and size saved on the agent. Files, commands, and runtime tools operate inside that sandbox.

Use the Default image for general work; choose Developer when the agent needs preinstalled developer tooling.

Nano

1 CPU, 1 GB RAM, 5 GB disk

Small

1 CPU, 2 GB RAM, 10 GB disk

Medium

2 CPU, 4 GB RAM, 20 GB disk

Large

4 CPU, 8 GB RAM, 40 GB disk

Start with the smallest size that fits the work. Move up only after a session runs short of memory, disk, or processing capacity because larger sandboxes spend more credits while active.