Devin Glossary: 40 Terms, From ACU to Outposts

Devin has its own vocabulary, and most of it maps to one of five things: where Devin runs, the agents and models doing the work, the context you give it, the work you automate, and how it is billed. Each definition below is one or two sentences drawn from Cognition’s documentation, with a link to the source and to our longer guide where we have one.

Read the steps as text

1. Surfaces. Devin Cloud, Devin Desktop, Devin CLI and Devin Review: where you work with Devin.
2. Agents and models. Devin Local, Fusion, SWE-2 and subagents do the work.
3. Context. Knowledge, Skills, Playbooks, Memory and DeepWiki tell Devin how your team works.
4. Automation. Automations, Handoff and Dynamic Workflows start and chain work for you.
5. Billing. Quota, on-demand credits and ACUs measure what that work costs.

1. Surfaces. Devin Cloud, Devin Desktop, Devin CLI and Devin Review: where you work with Devin.
2. Agents and models. Devin Local, Fusion, SWE-2 and subagents do the work.
3. Context. Knowledge, Skills, Playbooks, Memory and DeepWiki tell Devin how your team works.
4. Automation. Automations, Handoff and Dynamic Workflows start and chain work for you.
5. Billing. Quota, on-demand credits and ACUs measure what that work costs.

Surfaces

Devin Cloud

Devin’s autonomous cloud agent. Each session gets its own virtual machine with a shell, browser and full repository access, so it keeps working after you close your laptop. (Handoff docs) See Where Devin runs.

Devin Desktop

Cognition’s desktop editor, formerly Windsurf, renamed on June 2, 2026. It keeps the full editor and adds a layer for managing local and cloud agents. (Announcement) See Windsurf is now Devin Desktop.

Devin CLI

A local coding agent that runs in your terminal on macOS, Linux, WSL and Windows, with handoff to cloud Devin. (Devin CLI docs)

Agent Command Center

The Devin Desktop view for managing every agent you have running, local and cloud, in one place. (Agent Command Center docs)

Spaces

A Devin Desktop feature for grouping sessions, pull requests, files and context, and sharing that context between agents. (Announcement)

Devin Review

Devin’s pull-request reviewer. It groups related changes, explains them next to the diff and flags likely bugs; you can start it by commenting /devin review on a pull request. (Devin Review docs) See Using Devin Review.

Quick Review

An agentic review of your local changes inside Devin Desktop, run by a second agent before you commit. Its SWE-check model has no cost on paid plans and trials. (Quick Review docs)

Ask Devin

A way to ask questions about your codebase, plan tasks and start well-informed sessions, using DeepWiki’s understanding of your repositories. (Ask Devin docs)

Agents and models

Devin Local

The local agent in Devin Desktop and the same agent harness as Devin CLI. It works on your machine with your files and tools, and supports subagents, sandboxing, plan mode, worktrees and permission rules. (Devin Local docs)

Cascade

Windsurf’s original local agent. Devin Local replaced it, and Cascade was removed from Devin Desktop in version 3.9.19 on September 8, 2026. (Changelog)

Modes

Devin Local can run in Code, Smart, Ask, Plan or Bypass Permissions mode. Plan mode makes it plan before it changes anything. (Modes docs)

Subagents

Helper agents that a main agent starts for part of a task. Fast Context, for example, is a subagent that finds relevant code. (Fast Context docs)

Fusion

A pairing of a frontier “lead” model, which plans and checks the work, with a cheaper “sidekick” model that writes code and runs tests. Cognition says this costs “meaningfully less” than running the frontier model alone. (Fusion docs)

SWE-2

Cognition’s own software engineering model, available at Medium, High and Max reasoning effort. SWE-1.7 and SWE-1.6 are earlier generations; SWE-2 Flash is a lighter variant for Devin Desktop and Devin CLI. (Models docs)

Fast Context

A subagent that retrieves relevant code from your codebase, which Cognition says is up to 20 times faster, using its swe-grep models. (Fast Context docs)

Arena Mode

A Devin Desktop feature, launched as Windsurf’s Wave 14, that runs two agents side by side with the models’ names hidden so you can vote on which did better. (Changelog)

ACP (Agent Client Protocol)

An open protocol for communication between code editors and coding agents, similar to what LSP did for language servers. Any agent that speaks ACP can run inside Devin Desktop. (ACP docs)

Data Analyst Agent (DANA)

A Devin agent for database queries, data analysis and charts, available in Slack or the web app. (DANA docs)

Context

Knowledge

Codebase-level instructions and advice that Devin can use in every session, such as testing workflows or pull-request naming. Devin also builds Knowledge automatically from files like AGENTS.md, CLAUDE.md and .cursorrules. (Knowledge docs) See Knowledge, Playbooks and Skills.

Playbooks

Shareable, reusable prompts for a repeated task, which the docs liken to “a custom system prompt.” You attach one to a session with a macro. (Playbooks docs)

Skills

SKILL.md files that teach Devin a repeatable procedure, such as testing before opening a pull request. They follow the open Agent Skills standard, so the same files work in other AI coding tools. (Skills docs)

Rules

Instructions Devin Local follows in a workspace, kept in .devin/rules/. It also reads .windsurfrules and AGENTS.md. (Customizations docs)

Memory

Notes Devin saves on its own about your preferences, corrections and project lessons, carried into future sessions. Memory is personal and not shared with your team. (Memory docs)

DeepWiki

Automatically generated wikis for your repositories, with architecture diagrams, source links and summaries. A free DeepWiki MCP server covers public repositories. (DeepWiki docs)

MCP (Model Context Protocol)

A standard way to connect Devin to outside tools and data. You can install MCP servers from Devin’s marketplace or add your own. (MCP docs)

Blueprints

Descriptions of Devin’s environment for a repository, so sessions start with dependencies, tools and secrets ready. Devin can generate them from your repository for you to review. (Blueprints docs)

Secrets

API keys, site cookies and one-time password (TOTP) codes stored at organization, personal, repository or session level so Devin can sign in to tools. (Secrets docs)

Automation

Automations

Rules that start Devin sessions automatically from Slack messages, GitHub events, Linear updates, schedules or webhooks. Each has a trigger and actions, with optional conditions. (Automations docs)

Handoff

Passing a task from a local agent to a cloud Devin session so it keeps running. Devin CLI has a built-in /handoff command; other agents such as Claude Code or Codex hand off through the Devin API. (Handoff docs)

Local Hands

The reverse of handoff: a cloud Devin session runs commands and edits files on your own computer, through Devin Desktop or devin connect, with your approval for each action. (Local Hands docs)

Dynamic Workflows

A Python script that runs many Devin sessions in a fixed order, passing results between stages and resuming where it stopped. (Dynamic Workflows docs)

Stacked PRs

Devin’s way of splitting a large change into an ordered stack of GitHub pull requests that land together from the bottom up. (Stacked PRs docs)

Outposts

Running Devin sessions on infrastructure you control, such as your own VMs, containers or Kubernetes clusters. Devin’s planning still runs in Cognition’s cloud; commands, file edits and repository access happen on your machines. (Outposts docs)

Devin Security 2.0 and Security Swarm

Devin’s security scanning: scan repositories, review findings across your organization and assign fixes to Devin. Its docs page replaced the earlier Security Swarm guide. (Security docs)

Billing

Quota

The usage included with a self-serve plan. Pro and Teams full seats have daily and weekly allowances; Max has a larger weekly allowance with no daily cap. (Self-serve billing) See Devin pricing explained.

On-demand credits

Prepaid credits that pay for usage past your quota. They roll over every month and, per the docs, “never expire.” (Self-serve billing)

Full seat and flex seat

The two kinds of Teams seat. A full seat costs $40 a month with its own quota and Devin Desktop; a flex seat is free, draws on the team’s shared credits and has no Desktop access. (Self-serve billing)

ACU (Agent Compute Unit)

The unit Enterprise customers are billed in, at the rate set in their order form. ACUs measure the work Devin performs; Cognition does not publish a conversion to minutes or dollars. (Enterprise billing)

Session Insights

An analysis of a finished Devin session: what happened, what went wrong, what Knowledge it used and a better prompt for next time. It also shows the session’s cost, at no extra charge. (Session Insights docs)

Sleep

What a Devin session does after 30 minutes without activity (5 minutes for Lite and API-created sessions). A sleeping session uses almost no quota and wakes when you send a message. (Usage docs)

Sources

1. Devin documentation index — docs.devin.ai; each term above links to its own page
2. Usage — docs.devin.ai
3. Self-serve billing — docs.devin.ai
4. Enterprise billing — docs.devin.ai
5. Windsurf is now Devin Desktop — devin.ai

Terms change as Devin ships. Definitions checked against Cognition’s docs on 10 November 2026.

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