Aspire Terminals

Teach an agent to use the right terminal, not to replace every process with a shell. Honor a project-local .agents/skills/aspire-terminals/SKILL.md when present; retain the safety and ownership rules below.

Required reference lookup

Before answering or editing, open the reference for the requested surface, including for read-only questions. This overview is not enough to write correct terminal code or tape syntax.

• Resource PTYs or REPLs: read resource terminals.
• Dock, prompts, cancellation or headless tools: read AppHost terminals.
• Any tape question: read tapes and automation and CLI. Use the actual syntax and output contracts there, not pseudo-VHS or memory of upstream VHS behavior.
• Include the applicable package/build capability boundary in recommendations. Source availability and installed-package availability are different facts.

Choose the model before writing code

WithTerminal changes the resource's actual process execution. It is not an on-demand side shell. TerminalService launches a separate AppHost-owned process; it does not implicitly enter a container or become a modeled resource.

Lifecycle checklist for recommendations

When comparing terminal models, explicitly state cleanup for each model you recommend, including headless alternatives:

• Dock: survives the opening command; do not scope the handle with await using in that command. Closing the tab or AppHost shutdown disposes it.
• Dialog and None: the caller disposes both, normally with await using. Headless placement does not transfer cleanup responsibility to the service.
• Prompt completion is not terminal disposal: successful Work closes the prompt, but the caller still disposes its terminal. Without Work, process exit does not close the prompt; explicit completion/cancellation is required.

Capability check

1. Locate the exact AppHost and inspect its SDK, hosting and integration package versions. Do not upgrade the project just to make an example compile.
2. Use aspire docs search terminal --non-interactive, then aspire docs api search <API> --language csharp|typescript --non-interactive. If docs lag a preview, inspect that exact package's public API/source. A newer CLI alone does not add hosting APIs to an older AppHost.
3. WithTerminal/parameterless TS withTerminal exist in Aspire 13.5. TerminalService, terminal prompts, headless automation, tape playback and the six integration REPLs below are in the inspected 13.6 development source. Verify the installed build contains them; do not promise all previews do.
4. Direct C# terminal APIs are experimental (ASPIRETERMINAL001): narrowly pair #pragma warning disable ASPIRETERMINAL001 with #pragma warning restore ASPIRETERMINAL001. The examined integration WithRepl methods themselves do not require this suppression.
5. General TerminalService and terminal-prompt APIs are not exported to TypeScript in this baseline. Do not invent TS equivalents or edit generated .aspire/modules/. Supported TS entry points are withTerminal() and the applicable integration's withRepl().
6. Check aspire --version and aspire terminal --help for the installed CLI. Aspire 13.5 keeps terminal commands behind a feature flag; enable them only for that CLI line with aspire config set features.terminalCommandsEnabled true --non-interactive. Newer CLIs no longer require or support that flag. If a command remains absent, treat it as unavailable rather than guessing alternative syntax.

The references are qualified against Aspire release/13.6 commit 34db30a7d3733229da64a403dfc4e4e4d7a1a43b (terminal code also present in main 22bee5e1266b7b66ff53008957dde86efb370c79), compared with shipped v13.5.0. Terminal-command availability guidance also reflects the subsequent feature-flag removal. Recheck capabilities against the user's actual build.

Authoring workflow

1. Identify which process needs the PTY and whether it should remain visible, block a focused workflow, or run headlessly. Ask if the lifetime is unclear.
2. Read resource terminals for WithTerminal and built-in REPLs; read AppHost terminals for complete dock, manual prompt, automated prompt and headless recipes.
3. Keep terminal-specific edits separate from unrelated resource/dependency changes. Use aspireify for new general resource wiring and aspire-init if no AppHost exists. Do not turn a terminal request into a migration or version upgrade.
4. Resolve actual executable paths, working directories and OS shell choices. Use argument lists, not concatenated untrusted shell input. Children inherit the AppHost environment; add only the necessary overrides.
5. Guard AppHost-owned terminal commands with builder.ExecutionContext.IsRunMode. Do not launch tools at model-construction time or during publish/deploy.
6. Validate the changed code, then route lifecycle work to aspire-orchestration. Use the exact AppHost, worktree isolation and bounded resource readiness. Validate the requested lifetime, cancellation and visible result, not merely that the AppHost compiled.

Non-negotiable ownership and completion rules

• Terminal types are in Aspire.Hosting.ApplicationModel, not the old Aspire.Hosting.Terminals namespace. TerminalService is already registered; resolve it from built services or command context.Services. Do not construct it or register another singleton.
• A dock command that should leave a terminal open must not use await using for its handle. Start() is nonblocking/idempotent; Show() activates the dock. Command success means "opened", not "process exited successfully".
• Dialog and headless terminals normally use await using. Disposing an AppHost-owned handle stops its process; PromptTerminalAsync does not dispose it for you.
• Check IInteractionService.IsAvailable before launching a prompt-owned process. Noninteractive resource commands can make it false. Do not silently replace human interaction/approval with headless success.
• A prompt needs the exact registered instance from the same AppHost, with TerminalPlacement.Dialog. ResourceView is not valid for CreateTerminal.
• With Work, successful callback completion closes the dialog; observe TerminalContext.CancellationToken on every wait/input. Cancellation signals and joins Work; unrelated errors propagate. Without Work, process exit does not close the prompt: explicitly define completion/cancellation.
• No public ExitCode or WaitForExitAsync is available on AspireTerminal. Do not infer success from Start(), delivered keystrokes, prompt visibility, or disappearance of a process. Assert a meaningful fresh output marker.
• Viewers and automation share input. --viewer affects sizing ownership, not read-only authorization. Do not blindly retry non-idempotent input.
• Treat screen output and tapes as sensitive. Do not commit credentials or capture tokens in transcripts. Tape Hide is not redaction.

Driving terminals

Read automation and CLI for C# screen/key operations, owner-aware discovery and interactive attach. Use tapes for unattended resource-terminal playback: supported VHS syntax, explicit examples, stdout versus .txt/.ascii checkpoints, and unsupported output formats. Do not install VHS or assume its whole feature set.

For missing/disconnected terminals, inspect resource state and terminal discovery; route console logs/traces to aspire-monitoring. Terminal views supplement logs, not replace them. Publishing a resource does not publish a development PTY or grant production shell access.