Start your first session and see what Devin can do
Before you start your first session, make sure you’ve indexed and set up your repositories. These are the foundational steps that help Devin understand and work with your codebase.
Now that you’re all set up, kick off your first Devin session! This guide will walk you through the new session interface and help you understand the best ways to interact with Devin.
When you start a new session, you’ll see two primary modes: Ask and Agent.
Unless you already have a fully scoped plan, we recommend starting with Ask to work with Devin on constructing a plan, then moving to Agent mode to execute it.
You can trigger Ask mode from the main page or from a DeepWiki page.For Ask mode from the main page, toggle to Ask mode and select the repository/repositories you want to ask about.
For Ask mode from a DeepWiki page, type a query in the chat input at the bottom of the page and click Ask. This will automatically scope Devin’s knowledge to that repository specifically.
Learn more in our Ask Devin guide.Once you’ve worked with Devin to understand the problem and create a plan, you’re ready to move to Agent mode.
Agent mode is Devin’s full autonomous mode where it can write code, run commands, browse the web, and complete complex tasks end-to-end. Use Agent mode when you’re ready to:
Implement features or fix bugs
Create pull requests
Run tests and debug issues
Perform multi-step tasks that require code changes
You can choose which agent configuration Devin uses for your session. Different agents may have different capabilities or be optimized for specific types of tasks.Currently, we have a default agent that works well for most tasks, and a data analyst agent named Dana that is optimized for data analysis tasks.
If you’re unsure which agent to use, the default agent works well for most tasks.
Use @ mentions to give Devin specific context about files, repositories, or other resources. When you type @ in the chat input, you’ll see a dropdown of available mentions:
@Repos - Reference a specific repository
@Files - Reference a specific file in your codebase
Start with tasks that are smaller in scope and remember to instruct Devin with the level of detail that you would give to a human junior engineer. We’ve seen users work with Devin on everything from fixing small bugs to targeted refactors to large scale migrations.
Create a new endpoint /users/stats that returns a JSON object with user count and average signup age. Use our existing users table in PostgreSQL. You can reference the /orders/stats endpoint in statsController.js for how we structure responses. Ensure the new endpoint is covered by the StatsController.test.js suite.
Small frontend features
frontend features
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Ask AI
In UserProfileComponent, add a dropdown that shows a list of user roles (admin, editor, viewer). Use the styling from DropdownBase. When a role is selected, call the existing API to set the user role. Validate by checking that the selection updates the user role in the DB. Refer to your Knowledge for how to test properly.
Write unit tests
unit tests
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Ask AI
Add Jest tests for the AuthService methods: login and logout. Ensure test coverage for these two functions is at least 80%. Use UserService.test.js as an example.After implementation, run `npm test -- --coverage` and verify the coverage report shows >80% for both functions. Also confirm that tests pass with both valid and invalid credentials, and that logout properly clears session data.
Migrating or refactoring existing code
or refactoring existing code
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Ask AI
Migrate logger.js from JavaScript to TypeScript. We already have a tsconfig.json and a LoggerTest.test.js suite for validation. Make sure it compiles without errors and make sure not to change the existing config!After migration, verify by: 1) running `tsc` to confirm no type errors2) running the test suite with `npm test LoggerTest.test.js` to ensure all tests pass3) checking that all existing logger method calls throughout the codebase still work without type errors.
Updating APIs or database queries
unit tests
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Ask AI
We're switching from pg to sequelize (read https://sequelize.org/api/v6/identifiers). Please update the UserModel queries to use Sequelize methods. Refer to OrderModel for how we do it in this codebase.After implementation, verify by:1) running `npm run test:integration UserModel.test.js` to check all integration tests pass2) confirming query performance hasn't degraded by checking execution time on a test dataset of 1000 users3) validating that all CRUD operations still maintain data integrity by running `npm run test:e2e user-flows.test.js`
Create a quick PR (we recommend using this prompt in a Playbook)
Quick PR
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## OverviewThe task is to make a quick pull request to a repository.Since this is a 'quick' PR, you will not need to run any code or test anything; simply make a PR and the user will handle the testing. Your only responsibility is reading and writing code.## What's Needed From User- The repository to create a pull request## Procedure### Prepare your workspace1. Navigate to the relevant repository on your machine (clarify with the user if you can't figure it out). - Check out the main branch and note down the name of the main branch. - Checkout to a new branch since you'll be making a pull request. The name of the branch has to be of the format `devin/<your-branch-name>/X` where X is a random number. For example `devin/fix-popup/3234`. Run `git remote -v && git pull && git checkout -b devin/{branch-name}/$RANDOM` and replace `{branch-name}` with the name of the branch you want to create.2. Study the request, codebase, and plan out the changes - Review the most relevant files and code sections, identifying relevant snippets. - Inform the user of your plan### Work on the PR itself3. Make the code changes - Don't change anything that wasn't specifically requested by the user4. Make the PR - Commit and push the changes and tell the user. - See advice section for the exact command to make the PR - Make a pull request & review the pr to make sure it looks OK. - Ensure all GitHub actions pass successfully & make necessary changes until they do - Send the PR link to the user and summarize what you changed.5. Address any feedback from the review; send the PR link again every time you make any changes - If you need to make updates, just push more commits to the same branch; don't create a new one## Task Specification- PR link is included in your messages to the user- PR was reviewed after creation- PR does not include any stray changes- PR does not change anything that wasn't specifically requested by the user- PR description should include a summary of the changes, formatted as a checklist- PR description should mention that the code was written without testing, and include - [ ] Test the changes as an item- PR description should include the following footer: "This PR was written by [Devin](https://devin.ai/) :angel:"- PR description should include any metadata that the user has provided (e.g. linear ticket tags in the appropriate syntax)- PR description should not be malformatted (use --body-file instead of --body if the newlines are garbled!)## Forbidden Actions- Do NOT try to access github.com through the browser, you will not be authenticated.- NEVER force push on branches! Prefer merging over rebasing so that you don't lose any work.- Do NOT push directly to the main branch.## Advice and Pointers- Double check the name of the main branch (which could be `main` or `master`) using `git branch`.- For repos with CI/CD on github actions, you can check build logs using the gh cli. if you're asked to fix a build/fix lint, you should start by looking at recent build logs- Check `git status` before committing or adding files.- Use `git diff` to see what changes you have made before committing.- If you're updating an existing repo, use `gh cli` to make pull requests.- Send the PR link to the user every time you update & ask them to re-review so that it's convenient for them- You should already be authorized to access any repositories the user tells you about. If not, ask the user for access.
If you’d like to dig in to some more detailed examples of what Devin can do (and how), check out our introductory tutorials below.