---
title: "Your Agent Speaks MCP. Give It a Computer."
description: "Sprites are presented as disposable cloud computers for running coding agents and as tools agents can create for testing, debugging, benchmarking, and multi-service work. The post describes MCP as the transport and authorization layer, while progressive disclosure comes from plugins and skills that reveal capabilities only when needed; CLI, REST, and machine-readable /.sprite/llm.txt remain available. The hosted MCP server returns file reads as MCP resources and attaches safety annotations, marking read-only and destructive operations and flagging exec and service_start as crossing the Sprite boundary. Agents connect through sprites.dev/mcp and authenticate to a specific Fly.io organization, with configurable scoping, a default five-Sprite cap, and an mcp- name prefix. The design emphasizes durable filesystems, real networks, and near-zero idle cost instead of stateless sandboxes, while the post argues these properties make disposable computers practical for agent workflows."
---

# Your Agent Speaks MCP. Give It a Computer.

[Fly.io](https://yomu.fyi/company/fly-io) · Sep 3, 2026

**Type:** Announcement

## Summary

Sprites are presented as disposable cloud computers for running coding agents and as tools agents can create for testing, debugging, benchmarking, and multi-service work. The post describes MCP as the transport and authorization layer, while progressive disclosure comes from plugins and skills that reveal capabilities only when needed; CLI, REST, and machine-readable /.sprite/llm.txt remain available. The hosted MCP server returns file reads as MCP resources and attaches safety annotations, marking read-only and destructive operations and flagging exec and service\_start as crossing the Sprite boundary. Agents connect through sprites.dev/mcp and authenticate to a specific Fly.io organization, with configurable scoping, a default five-Sprite cap, and an mcp- name prefix. The design emphasizes durable filesystems, real networks, and near-zero idle cost instead of stateless sandboxes, while the post argues these properties make disposable computers practical for agent workflows.

## Context

Agents need disposable computers for tasks such as reproducing bugs, benchmarking code, testing dependency updates, running load generators, and coordinating multiple services. The post also argues that stateless sandboxes are insufficient because agents benefit from real filesystems and real networks.

## Approach / What changed

Sprites expose a hosted MCP server at sprites.dev/mcp, with client plugins and skills for progressive capability disclosure. The same underlying API remains accessible through the sprite CLI and REST, while /.sprite/llm.txt provides machine-readable documentation inside each Sprite. Sessions can be scoped to a Fly.io organization and constrained by Sprite count and name prefix.

## Takeaways

- Plugins combine a hosted MCP server with skills, so agents receive a short contextual capability description and retrieve details progressively.
- MCP file reads use resources; safety annotations distinguish read-only and destructive operations and flag exec and service\_start as reaching beyond the Sprite boundary.
- Sessions authenticate to one Fly.io organization and default to five Sprites with an mcp- name prefix; both the cap and prefix can be changed.

**Tags:** [AI Agents](https://yomu.fyi/topic/ai-agents), [MCP](https://yomu.fyi/topic/mcp), [Sandboxing](https://yomu.fyi/topic/sandboxing)

- Source: [Fly.io](https://fly.io/blog/sprites-mcp)
- Source URL: https://fly.io/blog/sprites-mcp
- Ingested by Yomu: 2026-09-03T12:00:50.798Z

[Read original post](https://fly.io/blog/sprites-mcp)