Normalizes non-standard code-fence language tags across `docs/**` so a strict highlighter (Shiki, used by Fumadocs) won't fail the build on an unrecognized language, and unifies redundant synonym tags onto one canonical form per language. The current renderer (Speed-Highlight) detects the language from the code content, not the fence label, so this drift wasn't visible until now. ## Changes - `hcl` -> `tf` (199 fences, including indented ones nested in numbered/bulleted lists). Shiki ships `hcl` and `terraform` as two distinct grammars (not aliases); every `hcl`-tagged fence in `docs/**` is actually Terraform resource/data/provider syntax, so the more specific `terraform` grammar is correct for all of them. `tf` is Shiki's own alias for that grammar, and it's also what GitHub's own markdown renderer resolves to the same HCL/Terraform highlighting. - `pwsh`/`powershell` -> `ps1`. Both `ps` and `ps1` are registered PowerShell aliases in Shiki, but on GitHub's renderer only `.ps1` is a registered file extension (`.ps` isn't), so `ps1` renders identically to `powershell` there today while bare `ps` would silently lose highlighting. - `env` -> `dotenv` (a dedicated Shiki grammar for `KEY=VALUE` files) - `text`/`output`/`none`/`url` -> `txt`. Same built-in plain-text fallback either way, just shorter. - `Dockerfile` -> `dockerfile` (lowercase) - `bash`/`shell` -> `sh` (732 fences). Shiki and GitHub both alias all three to a single shell grammar; this was already the style guide's stated preference, just not enforced across the existing corpus until now. - `markdown` -> `md` (4 fences). Alias of the same grammar in both Shiki and GitHub. - `jsonc` -> `json` (1 fence). The block has no comments or trailing commas, so it doesn't need the comments-capable grammar. - `ts` -> `tsx` (2 fences, `docs/about/contributing/frontend.md`). Verified the actual content tokenizes identically under both grammars, and a sibling block in the same file already needs `tsx` for real JSX, so unifying to one tag is safe for this file. Documented a caveat: `tsx` mis-tokenizes the legacy angle-bracket type-assertion syntax (`<Type>value`), which is invalid in real `.tsx` files anyway, so use `value as Type` instead. - `yml` -> `yaml` (1 fence) - Updated `docs/.style/style-guide/formatting.md` to document all canonical tags `promql` (2 fences) and `caddyfile` (2 fences) are left as-is. Shiki doesn't bundle a grammar for either, so they need a custom grammar registration when the site adopts Shiki, rather than degrading to `txt`. Tracked as follow-up work under DOCS-118 and [DOCS-544](https://linear.app/codercom/issue/DOCS-544/vendor-a-local-promql-grammar-for-shiki-syntax-highlighting) (promql). Does not touch `offlinedocs/`. Linear: [DOCS-476](https://linear.app/codercom/issue/DOCS-476/normalize-docs-code-fence-languages-de-risk-shikifumadocs) <details> <summary>How the fence tags were verified</summary> Each tag was tested against a real `shiki@latest` highlighter instance (`codeToHtml`/`codeToTokens`) and cross-checked against GitHub's `@wooorm/starry-night` grammar sources (the renderer that actually displays these `.md` files today, in repo browsing and PR diffs), since that's what determines whether brevity is safe before Shiki adoption: ```text FAIL env -- Language `env` is not included in this bundle. FAIL Dockerfile -- Language `Dockerfile` is not included in this bundle. FAIL promql -- Language `promql` is not included in this bundle. FAIL caddyfile -- Language `caddyfile` is not included in this bundle. FAIL pwsh -- Language `pwsh` is not included in this bundle. FAIL output -- Language `output` is not included in this bundle. ``` `hcl` doesn't error in Shiki, since it's a real grammar, but that's exactly the trap: it was silently rendering every fence with the generic HCL grammar instead of the Terraform-specific one. Every `hcl`-tagged fence in `docs/**` was manually checked against `origin/main` and is genuinely Terraform content. For `ts`/`tsx`, tokenizing the actual doc content confirmed identical output under both grammars; a synthetic test with the legacy angle-bracket cast syntax confirmed `tsx` degrades on that specific construct, which the style guide now calls out. The first normalization pass only matched fence tags at column 0 (`^```tag$`), missing tags indented inside numbered/bulleted lists. A follow-up pass caught the remaining occurrences at any indentation level. </details> --- *This PR description and the underlying changes were prepared with Coder Agents assistance.*
About
Coder is a self-hosted platform for running AI coding agents and cloud development environments on infrastructure you control. It works with any cloud, IDE, OS, Git provider, and IDP.
Coder Workspaces
Coder Workspaces are cloud development environments defined with Terraform, connected through a secure Wireguard tunnel, and automatically shut down when not in use. Agents and developers share the same workspace infrastructure.
- Defined in Terraform: Templates describe the infrastructure for each workspace, from EC2 VMs and Kubernetes Pods to Docker containers.
- Any architecture and OS: Support ARM and x86-64 across Windows, Linux, and macOS from a single deployment.
- Managed by admins: Platform teams create and maintain templates that enforce approved images, resource limits, and security policies.
- Accessed from any IDE: Connect through VS Code, JetBrains, Cursor, a web terminal, remote desktop, or SSH.
- Automatic shutdown: Idle workspaces stop automatically to reduce cloud spend, and restart in seconds when needed.
Coder Agents
Coder Agents is a native AI coding agent built into Coder. The agent loop runs in the Coder control plane on your infrastructure, not in the workspace and not in a vendor's cloud. Developers interact with agents through the web UI or the REST API for programmatic and CI-driven workflows.
- Self-hosted agent loop: The control plane handles planning, model calls, and tool dispatch. Workspaces have zero AI awareness.
- No API keys in workspaces: LLM credentials stay in the control plane.
- Any model: Anthropic, OpenAI, Google, Bedrock, or self-hosted endpoints. Switching is a configuration change.
- Governance and cost controls: Centralized model approval, per-user spend limits, and audit logging.
- Open source and inspectable: The full platform is available to audit and extend.
IDE support
You can use:
-
Any Web IDE, such as
- code-server
- JetBrains Projector
- Jupyter
- And others
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Your existing remote development environment:
-
A file sync such as Mutagen
Why remote development
Provisioning consistent development environments for a large engineering team is difficult. Each developer has preferences for operating systems, editors, and toolchains, and ensuring a reliable build environment across all of them is a maintenance burden. A missed step during onboarding or an unsupported local configuration can cost hours of debugging.
Remote development solves this by moving the environment off the developer's machine and into managed infrastructure. The developer's laptop becomes a portal into the actual compute where work happens. If a device is lost or replaced, access is simply revoked; no source code or credentials are stored locally.
This approach provides:
- Speed: Server-grade hardware accelerates builds, tests, and large workloads without requiring expensive local machines.
- Consistency: Infrastructure tools such as Terraform, nix, Docker, and Dev Containers produce identical environments for every developer.
- Security: Source code stays on private servers. Users and groups are managed through SSO and RBAC.
- Compatibility: Workspaces share infrastructure configurations with staging and production, reducing configuration drift.
- Accessibility: Browser-based IDEs and remote IDE extensions let developers work from any device, including lightweight laptops, Chromebooks, and tablets.
Read more on the Coder blog, the Slack engineering blog, or from Alex Ellis at OpenFaaS.
Why Coder
The key difference between Coder and other platforms is that the entire system, agent loop, control plane, model routing, and workspace provisioning, runs on infrastructure you control.
For agents, this means platform teams can:
- Run the entire agent loop on their infrastructure, with no SaaS dependency for orchestration.
- Define MCP servers, skills, and system prompts centrally so every agent session starts with the same tools, policies, and context.
- Keep LLM credentials out of workspaces entirely.
- Tie every agent action to an authenticated user identity.
- Support air-gapped and restricted-network deployments with self-hosted models.
For workspaces, this means admins can:
- Support any architecture (ARM, x86-64) and operating system (Windows, Linux, macOS).
- Modify pod/container specs, such as adding disks, managing network policies, or setting/updating environment variables.
- Use VM or dedicated workspaces, developing with Kernel features (no container knowledge required).
- Enable persistent workspaces, which are like local machines, but faster and hosted by a cloud service.
Pricing
Coder is free and open source under the GNU Affero General Public License v3.0. All developer productivity features are included in the open source version. A Premium license is available for enhanced support and custom deployments.
How Coder works
Coder workspaces are represented with Terraform, but you do not need to know Terraform to get started. The Coder Registry provides production-ready templates for AWS EC2, Azure, Google Cloud, Kubernetes, and other providers.
Providers and compute environments
Workspaces can include more than just compute. Terraform can add storage buckets, secrets, sidecars, and other resources.
See the templates documentation for details.
What Coder is not
-
Coder is not an infrastructure as code (IaC) platform.
- Terraform is the first IaC provisioner in Coder, allowing Coder admins to define Terraform resources as Coder workspaces.
-
Coder is not a DevOps/CI platform.
- Coder workspaces can be configured to follow best practices for cloud-service-based workloads, but Coder is not responsible for how you define or deploy the software you write.
-
Coder is not an online IDE.
- Coder supports common editors, such as VS Code, vim, and JetBrains, all over HTTPS or SSH.
-
Coder is not a collaboration platform.
- You can use Git with your favorite Git platform and dedicated IDE extensions for pull requests, code reviews, and pair programming.
-
Coder is not a SaaS/fully-managed offering.
- Coder is a self-hosted solution. You must host Coder in a private data center or on a cloud service, such as AWS, Azure, or GCP.

