> 🤖 This PR was written by Coder Agents on behalf of Jake Howell. Fixes coder/coder#25692. Closes coder/coder#25692. Supersedes coder/coder#28250. ## Problem `AgentLogs` virtualizes rows with a **fixed** `itemSize` (20px), so react-window sets the total scroll height to `itemCount * 20`. Log entries that contain newlines render taller than 20px, so the estimate falls short: tall rows overlap the rows below them and the true bottom sits past where `scrollToItem(..., "end")` can reach. The last lines become unreachable. ## Fix Switch to `VariableSizeList` and measure each row with a `ResizeObserver`, feeding the real height back via `resetAfterIndex`. The total scroll height now tracks the real content, so the bottom is always reachable. `AgentRow` and `TaskPage` only change the ref type; their existing autoscroll now lands correctly. ## Before / After Dogfooded on a local instance with a workspace whose agent logs include multi-line entries (241 entries, every 30th a 6-line block, plus a final bottom-marker line). Same workspace, same scroll interaction, `main` vs this branch: <!-- linear:table-colwidths:266,266,266 --> | | Before (`main`, `FixedSizeList`) | After (this PR, `VariableSizeList`) | | -- | -- | -- | | **A multi-line entry** | Painted into a 20px slot, so it collides with the rows above and below (text on top of text). | Rendered at full height in its own space, neighbours no longer overlap. | | |  |  | | **Scrolled to the bottom** | Total height is short, so normal scrolling stops early: the final marker line is clipped and unreachable. | Height tracks real content: the final marker line is fully visible and reachable. | | |  |  | ## Validation The new `AgentLogs.test.tsx` renders rows measured taller (40px) than the estimate and asserts the scroll area is sized from measured heights. Run against the `main` implementation it fails, against this branch it passes: ``` # main (FixedSizeList): scroll area = 5 rows * 20px - Expected 200 + Received 100 → FAIL # this branch (VariableSizeList): scroll area = 5 rows * measured 40px ✓ AgentLogs.test.tsx (1 test) → PASS ``` Also green: `tsc`, `biome check`, and the AgentRow (25) + TaskPage (46) + AgentLogs (3) Storybook interaction tests. <details><summary>Dogfood details and decision log</summary> **Dogfood setup** (SHA `1228dcfe8d`, `./scripts/develop.sh`): template `lognl2` (a `coder_agent` on a `null_resource` so the agent authenticates against a real build), workspace `lognl-demo2`. Posted 241 log entries via `PATCH /api/v2/workspaceagents/me/logs`, every 30th a 6-line `\n` entry plus a bottom marker; confirmed the 8 multi-line entries persisted with embedded newlines. On the fixed build, at maximum scroll the DevTools console reported `scrollTop 5204`, `scrollHeight 5460`, `clientHeight 256`, `remaining 0`, marker clipped `0px`; height is self-consistent (`innerHeight 5428` + 16px top + 16px bottom padding = `5460`). **Decision log** * coder/coder#28250 treated this as an autoscroll problem. Wrong: the height calculation is the bug, so no scroll target can reach a bottom placed out of range. Reverted. * Only embedded newlines make a row exceed 20px; long lines do not wrap (they overflow horizontally). A fixed constant can't cover a variable line count, so measuring is the robust fix. * `resetAfterIndex` can't run from a row's first-mount measurement effect because the list ref is assigned after child rows commit; the lowest changed index is recorded and flushed from a parent layout effect. </details> Evidence images are hosted on the `devex-407-evidence` branch of the author's fork (`jakehwll/coder`) to keep this repo's diff clean.
Coder is a self-hosted platform for cloud development environments and AI coding agents. Workspaces are defined with Terraform, connected through a secure Wireguard® tunnel, and automatically shut down when not used. Coder Agents runs a native AI coding agent whose loop executes in the control plane on your infrastructure, with no API keys in workspaces.
- Define cloud development environments in Terraform
- EC2 VMs, Kubernetes Pods, Docker Containers, etc.
- Automatically shutdown idle resources to save on costs
- Onboard developers in seconds instead of days
- Delegate coding work to AI agents on your infrastructure
- Bring any model (Anthropic, OpenAI, Google, Bedrock, self-hosted)
- No LLM credentials in workspaces, user identity on every action
- Centralized model governance, cost tracking, and audit logging
Quickstart
Check out our install guides for other methods and a complete tutorial.
Try Coder with the install script on Linux and macOS, or grab the latest binary or installer from GitHub Releases on Windows:
curl -L https://coder.com/install.sh | sh
Start the server and open http://localhost:3000 to create your initial user, create a Docker template, and provision your first workspace:
coder server
For a production deployment, add a PostgreSQL database (version 13 or later) and an external access URL, and see our validated architectures for sizing and infrastructure guidance:
coder server --postgres-url <url> --access-url <url>
Without these flags, Coder uses a built-in database and sets up a *.try.coder.app access URL for evaluation. Use coder --help for the full list of flags and environment variables.
Documentation
Browse the documentation or visit a specific section below:
- Workspaces: Workspaces contain the IDEs, dependencies, and configuration information needed for software development
- Templates: Templates are written in Terraform and describe the infrastructure for workspaces
- Coder Agents: Delegate coding work to AI agents running on your self-hosted infrastructure
- AI Gateway: Centralize authentication, auditing, and cost controls for AI tooling
- Administration: Learn how to operate Coder
- Premium: Learn about paid features built for large teams
- IDEs: Connect your existing editor to a workspace
Support
Open an issue for bugs and feature requests.
For community support, showcasing what you built, and feedback on in-progress features, join our Discord or GitHub Discussions.
Dedicated support is included in Coder Premium. For more information, visit coder.com/pricing.
Integrations
New integrations are always in progress. Open an issue to request one. Contributions are welcome in any official or community repository.
Official
- Coder Registry: Templates, modules, and integrations for common development environments
- Coding Agents: Run agents like Claude Code, Codex, and OpenCode isolated in Coder workspaces
- coderd Terraform Provider: Declaratively manage your Coder deployment configuration as code
- VS Code Extension: Open any Coder workspace in VS Code with a single click
- JetBrains Toolbox Plugin: Open any Coder workspace from JetBrains Toolbox with a single click
- Dev Containers: Build development environments using
devcontainer.jsonon Docker, Kubernetes, and OpenShift - Kubernetes Log Stream: Stream Kubernetes Pod events to the Coder startup logs
- Self-Hosted VS Code Extension Marketplace: A private extension marketplace that works in restricted or airgapped networks integrating with code-server.
- GitHub Actions: An action to set up the Coder CLI in GitHub workflows
Community
- Coder Discord: Chat with the community, get support, and hear about new product updates first
- Community Templates: Community-contributed workspace templates in the Coder Registry
- Community Modules: Community-contributed modules to extend Coder templates
- Coder Template GitHub Action: A GitHub Action that updates Coder templates
- Coder Agents Chat Action: A GitHub Action that starts a Coder Agents chat against a GitHub issue or pull request
Contributing
New contributors are always welcome. If you are new to the Coder codebase, see the contribution guide to get started.
Hiring
Apply on the careers page if you are interested in joining the team.
