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Kyle Carberry
159089686a
## Problem Mid-turn workspace MCP discovery was broken when an agent was still cold-starting. `PrepareTools` in `chatd.go` flipped `workspaceMCPDiscovered = true` *before* calling `discoverWorkspaceMCPTools`, so a failed discovery attempt permanently blocked retries within the turn. Customer-reported repro: - New chat with no pre-selected workspace. - LLM calls `create_workspace` mid-turn at `23:35:05`. - `PrepareTools` fires, dials the agent with a 30s timeout, dial times out at `23:38:15`, `discoverWorkspaceMCPTools` returns empty. - Agent connects at `23:38:29`, 14 seconds later. - `workspaceMCPDiscovered` was already true, so `PrepareTools` never retried for the rest of the turn. MCP tools only appeared on the next user message. A naive retry loop in `PrepareTools` would also miss the bigger picture: a workspace boot can take several minutes (EC2 cold start, 10 min startup scripts), and the chatloop only gets a chance to call `PrepareTools` between LLM steps. ## Fix Do the workspace MCP discovery from inside the tool that already waits for the agent. `chattool.CreateWorkspace` and `chattool.StartWorkspace` call `waitForAgentReady`, which has a 2 min agent-online budget plus a 10 min startup-script budget. By the time they fire `OnChatUpdated`, the agent is `Ready`. The chatd `onChatUpdated` callback now launches an async `primeWorkspaceMCPCache` goroutine on every bind that has a valid workspace ID: - The primer calls `discoverWorkspaceMCPTools` until it returns a non-empty list or `workspaceMCPPrimeMaxWait` (30s) elapses, with a 2s backoff between attempts. The bounded wait handles the short race between agent-online and the agent's MCP `Connect` settling. - The primer runs asynchronously so the tool itself never blocks. Some templates simply do not advertise MCP tools, in which case the primer would otherwise spend its full budget for nothing. - The primer shares the chat `ctx` (not a detached one) so it is canceled together with the chat. A dangling primer would re-dial the workspace conn after `runChat`'s deferred `workspaceCtx.close()` and leak that conn. - `inflight.Add(1)` ensures server shutdown still waits for any in-progress primer. - `PrepareTools` is simplified back to a single discovery call. It now only sets `workspaceMCPDiscovered = true` on success, so an empty result no longer permanently blocks discovery within the turn. The cache hit warmed by the primer makes that call cheap in the common case; the dial fallback handles the rare cache miss. ## Tests All in `coderd/x/chatd/chatd_internal_test.go`: - `TestPrimeWorkspaceMCPCache_SuccessOnFirstAttempt` — single `ListMCPTools` call returning tools populates the cache. - `TestPrimeWorkspaceMCPCache_RetriesUntilToolsAppear` — first call empty, second returns tools; primer retries past the backoff and writes the cache. Uses `quartz.Mock.Trap` on `NewTimer`. - `TestPrimeWorkspaceMCPCache_GivesUpAfterDeadline` — `ListMCPTools` always empty; primer stops at `workspaceMCPPrimeMaxWait` and refuses to cache the empty result so PrepareTools can retry on the next step. The existing integration test `TestRunChat_WorkspaceMCPDiscoveryAfterMidTurnCreateWorkspace` continues to pass and now also exercises the async-primer path end-to-end via the create_workspace tool. ``` go test ./coderd/x/chatd/... -count=1 go test ./coderd/x/chatd/ -race -count=1 make pre-commit ``` <details> <summary>Design notes</summary> - The first iteration of this PR added retry+cooldown+failure-cap logic inside `PrepareTools`. It worked for the customer's ~30s race window but did not help workspaces that take several minutes to boot, because `PrepareTools` only fires between LLM steps. Reviewer pointed out the right place to handle this is the tool itself; the current implementation does that. - Why async: a primer that ran synchronously inside the `OnChatUpdated` callback blocked the create_workspace tool from returning for up to `workspaceMCPPrimeMaxWait`, which broke `TestCreateWorkspaceTool_EndToEnd` and would hurt any template that does not expose MCP tools. Decoupling lets the tool return immediately and lets the primer warm the cache concurrently with the next LLM step. - Why share the chat `ctx` rather than `context.WithoutCancel(ctx)` (the title-generation pattern): the primer touches `workspaceCtx.getWorkspaceConn`, which `runChat`'s deferred `workspaceCtx.close()` invalidates. A detached primer outliving the chat would dial a fresh conn and leak it. - The constant naming distinguishes `workspaceMCPDiscoveryTimeout` (35s per-call dial budget, unchanged from #25169) from `workspaceMCPPrimeMaxWait` (30s total budget for the post-ready primer loop) and `workspaceMCPPrimeRetryInterval` (2s between empty-result retries). </details> Follow-up to #25169. --- _This pull request was generated by Coder Agents._
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
The most convenient way to try Coder is to install it on your local machine and experiment with provisioning cloud development environments using Docker (works on Linux, macOS, and Windows).
# First, install Coder
curl -L https://coder.com/install.sh | sh
# Start the Coder server (caches data in ~/.cache/coder)
coder server
# Navigate to http://localhost:3000 to create your initial user,
# create a Docker template and provision a workspace
Install
The easiest way to install Coder is to use the
install script for Linux
and macOS. For Windows, use the latest ..._installer.exe file from GitHub
Releases.
curl -L https://coder.com/install.sh | sh
You can run the install script with --dry-run to see the commands that will be used to install without executing them. Run the install script with --help for additional flags.
See install for additional methods.
Once installed, you can start a production deployment with a single command:
# Automatically sets up an external access URL on *.try.coder.app
coder server
# Requires a PostgreSQL instance (version 13 or higher) and external access URL
coder server --postgres-url <url> --access-url <url>
Use coder --help to get a list of flags and environment variables. See the install guides for a complete tutorial.
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
- Administration: Learn how to operate Coder
- Premium: Learn about paid features built for large teams
- IDEs: Connect your existing editor to a workspace
Support
Feel free to open an issue if you have questions, run into bugs, or have a feature request.
Join our Discord to provide feedback on in-progress features and chat with the community using Coder!
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
- 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
- JetBrains Gateway Plugin: Open any Coder workspace in JetBrains Gateway 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
- Community Templates: Community-contributed workspace templates in the Coder Registry
- Community Modules: Community-contributed modules to extend Coder templates
- Provision Coder with Terraform: Provision Coder on Google GKE, Azure AKS, AWS EKS, DigitalOcean DOKS, IBMCloud K8s, OVHCloud K8s, and Scaleway K8s Kapsule with Terraform
- Coder Template GitHub Action: A GitHub Action that updates Coder templates
- Discord: Chat with the community and provide feedback on in-progress features
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.