Grass vs Devin: Autonomous Delegation vs Real-Time Agent Oversight
Devin handles tasks autonomously in the cloud. Grass keeps you in the loop while your agent works. They're built for different levels of trust and different types of tasks.
Devin and Grass are built on different assumptions about how much you want to be involved while an agent works. Devin is designed for autonomous delegation — you assign a task and Devin handles it end-to-end in the cloud, opening a PR when it is done. Grass is designed for real-time oversight — your agent runs on your own infrastructure, and Grass keeps you connected to it from your phone, with live output and per-action approval. If you want to hand off a well-defined task and review the result later, Devin is built for that. If you want to stay in the loop while Claude Code or OpenCode works through something complex, Grass is the interface for that.
TL;DR
- Devin is a fully autonomous AI software engineer that runs tasks in the cloud and delivers a PR
- Grass is a mobile interface for monitoring and controlling Claude Code or OpenCode on your own infrastructure
- Devin requires no oversight during execution — that is the point; Grass is built for developers who want oversight
- Devin starts at $20/month; Grass is free for local use
- These products are rarely direct alternatives — most developers would use them for different types of tasks
What is Devin?
Devin is an autonomous AI software engineer built by Cognition AI. You assign Devin a task — fix a bug, build a feature, migrate a codebase — and it works independently in a cloud-hosted environment with its own terminal, editor, and browser. When it is done, it opens a pull request. You can assign tasks via the Devin web interface, Slack, or Jira. Devin 2.0, released in late 2025, starts at $20/month with usage-based pricing. See the Devin documentation for the full capability overview.
What is Grass?
Grass is a native iOS app (with an Android PWA) that connects to coding agents running on your own machine or a transient dev server like Daytona. You run grass start in your project directory, scan the QR code, and get live output streaming, per-action approval modals, and bidirectional chat from your phone. Grass supports Claude Code and OpenCode. It is free for local use — your agent runs on your infrastructure, not a third-party cloud.
Head-to-head: Devin vs Grass
| Dimension | Devin | Grass |
|---|---|---|
| Agent type | Devin's own autonomous agent | Claude Code, OpenCode |
| Where agent runs | Devin's cloud infrastructure | Your machine or Daytona workspace |
| Oversight model | Autonomous — delivers result at end | Real-time — live output and per-action approval |
| Mobile interface | Web interface (task assignment + status) | Native iOS app; Android PWA |
| Per-action approval | No — agent runs to completion autonomously | Core feature — approve or deny every tool action |
| Task assignment | Natural language, Slack, Jira | Grass chat interface or terminal |
| Code/data location | Devin cloud infrastructure | Your machine or your server |
| Pricing | From $20/month (usage-based) | Free for local use |
The key difference is the oversight model. Devin is built around autonomy — its value proposition is that you do not need to supervise it. It plans, executes, and delivers. The developer reviews the PR at the end. Claude Code running via Grass is different: it runs in default permission mode, pausing at agent approval gates before writing files or running commands. Grass surfaces those pauses as phone notifications. The developer stays in the loop throughout.
Neither model is objectively better — they suit different tasks and different levels of trust.
When to use Devin
Devin is well-suited for well-scoped, self-contained tasks where you trust the agent to work independently and you want to review the result rather than the process. Good fits include backlog tasks with clear acceptance criteria, codebase migrations with defined source and target states, test coverage improvements, and dependency upgrades. Devin is also the right choice if your team uses Jira or Slack as the primary task interface — its integrations for assigning work via those tools are a genuine workflow advantage.
Cognition reports that Devin 2.0 completes over 83% more junior-level development tasks per Agent Compute Unit compared to its predecessor, based on internal benchmarks. If your priority is reducing developer involvement in execution, Devin's autonomous model delivers that.
When to use Grass
Grass is the right choice when you are running Claude Code or OpenCode and want to stay connected to the session from your phone. Specifically:
You need per-action oversight. For tasks where you want to review each file write and bash command before it executes, Claude Code's default permission mode with Grass's approval modals gives you that. Devin's autonomous model does not offer per-action control.
Your code stays on your infrastructure. Grass connects to agents running on your machine or a Daytona workspace. If your codebase contains sensitive data or you have restrictions on where code can be processed, Grass keeps it on infrastructure you control.
Your task is exploratory or iterative. Devin works best on well-defined tasks. Claude Code via Grass is better suited to tasks that require mid-session redirection — you can send a follow-up prompt from your phone as the agent's approach becomes clearer.
You run long sessions overnight. According to Anthropic's research on agent autonomy, Claude Code can run for 45+ minutes per turn on complex tasks. Grass lets you monitor a running session, handle agent approval gates as they arrive, and check progress at any point without being at a laptop. The agent runs on your machine or Daytona — it does not need Devin's cloud infrastructure.
The bottom line
Devin and Grass are rarely direct alternatives. Devin replaces a developer for autonomous, self-contained tasks — you delegate and review. Grass keeps a developer connected to their own agent during complex, long-running, or iterative work. Many developers would use both: Devin for well-scoped backlog tasks, Claude Code via Grass for the work that benefits from active oversight. The question is not which is better — it is which model matches the task and the level of involvement you want.
Frequently asked questions
Can Grass connect to a Devin session?
No. Devin runs entirely on Cognition's cloud infrastructure — there is no way to connect Grass to a Devin session. Grass connects to Claude Code and OpenCode sessions running on infrastructure you control: your local machine or a transient dev server like Daytona. Devin and Grass are complementary tools for different parts of the delegation spectrum, not competing interfaces for the same agent.
What is the key difference in how Devin and Claude Code handle human oversight?
Devin is designed for maximum autonomy — you delegate a task and Devin executes it end-to-end, with minimal checkpoints. Claude Code in default permission mode takes the opposite approach: it pauses at agent approval gates before potentially destructive actions, keeping you in the loop for consequential decisions. Grass makes those Claude Code approval gates accessible from your phone, so you get Claude Code's granular oversight without being chained to a terminal.
How does Devin's pricing compare to running Claude Code with Grass?
Devin starts at $20/month with usage-based pricing on top, oriented toward teams and frequent use. Claude Code usage is billed through your Anthropic API key at standard API rates, or included in your Claude Pro or Max subscription. Grass is free for local use. The cost profile is very different: Devin is a premium fully-managed service; Claude Code with Grass is a self-managed setup where you control the compute costs.
Which is better for overnight or long-running tasks — Devin or Grass with Claude Code?
Devin is purpose-built for this: it runs in the cloud, handles multi-hour tasks autonomously, and doesn't require your laptop to stay on. Claude Code with Grass can also run overnight — especially when using a transient dev server like Daytona so your laptop doesn't need to stay on — but you're more involved in managing approval gates along the way. If you want to fully delegate and check back on results, Devin is the better fit. If you want live oversight and control during execution, Grass with Claude Code is.
Where does my code go when I use Devin versus Claude Code with Grass?
With Devin, your code and task context are sent to Cognition's cloud infrastructure for processing. With Claude Code and Grass, your code stays on your own machine or your own Daytona workspace — Grass itself has no cloud infrastructure. It connects directly from your phone to wherever you're running the agent. For teams with data residency requirements or codebases that shouldn't leave their own infrastructure, Claude Code with Grass is the locally-controlled option.
Can I use Devin and Grass together in the same workflow?
Indirectly, yes. Some developers use Devin for fully autonomous cloud tasks and Claude Code with Grass for tasks that need real-time oversight and approval. They operate on separate codebases and sessions — there's no integration between them. The choice is task-by-task: delegate fully to Devin for well-defined, trusted tasks; use Claude Code with Grass for tasks where you want to stay in the loop.