aca-sandboxes

Use when the user wants to create, manage, or operate Azure Container Apps sandboxes — hardware-isolated microVMs driven by the `aca` CLI. USE FOR: create sandbox group, create sandbox, aca doctor, aca auth login, install aca, exec in sandbox, sandbox shell, fs read/write, expose port, mount volume, snapshot/suspend/resume sandbox, commit to disk, egress rules, secrets, identity, list disk images, Python SDK install, Azure portal sandbox surface, compare to Dynamic Sessions or Container Apps, scenarios like coding agents, code interpreter, agent swarms, computer-use, web apps, MCP hosting. DO

Sandboxes

Hardware-isolated microVMs on Azure Container Apps. Snapshot/resume, scale-to-zero, sub-second startup, deny-default egress. This skill drives sandboxes through the aca CLI — one command surface, no ambiguity. Self-contained — everything is under references/ in this folder.

What it is

Resource type: Microsoft.App/SandboxGroups (preview).
Isolation: each sandbox is its own microVM, safe for untrusted code.
Startup: sub-second from a prewarmed pool; suspend/resume preserves full memory + disk.
Scale: zero to thousands; pay nothing when idle.
Auth: aca delegates to az login — same identity, same MFA.

⚠️ The az CLI has no sandbox commands. Sandbox groups and sandboxes are managed by aca — not by az containerapp …. The az containerapp commands are for the older Apps / Jobs surface and do not touch sandboxes. If you see az containerapp sandbox … in a snippet, it's wrong.

⚠️ There is no aca sandbox-group (hyphenated) command group. Every group-level verb is aca sandboxgroup … (no hyphen): aca sandboxgroup create / get / list / delete / role create / identity assign / secret set / disk list / volume create / snapshot …. The hyphenated --sandbox-group <name> is the flag you pass to top-level commands to select the default group — it is not a verb. If you see aca sandbox-group … in a snippet (including for MCP connectors, credentials, or triggers), it's wrong / fabricated.

⚠ Required cues per response type (non-negotiable)

Before composing your answer, identify the user's intent and ensure the cues below are present. These are acceptance criteria, not suggestions — a response is incomplete if it omits any cue for its intent.

User intent	Cues your response MUST include
Install the `aca` CLI (any OS)	(1) The curl/iwr one-liner from references/install.md — use the `https://aka.ms/aca-cli-install` (Linux/macOS) and `https://aka.ms/aca-cli-install-ps` (Windows) short URLs. (2) `aca --version` + auth-aware sign-in (`az account show -o none 2>$null; if ($LASTEXITCODE -ne 0) { az login }`, then `aca auth login` to acquire an `aca` token — never call `az login` or `aca auth login` unconditionally; gate both on a status check) + `aca doctor`. The CLI surface for auth is `aca auth login` (the top-level `aca` binary does not have a bare `login` subcommand). (3) The explicit sentence: "this same install path is also used inside sandboxes and containers for agent-driven self-installs."
Bootstrap a sandbox group (one-time setup)	The 4-step flow: check auth first (`az account show -o none 2>$null; if ($LASTEXITCODE -ne 0) { az login }`, then `aca auth login` if `aca` is not yet authenticated — never call `az login` or `aca auth login` unconditionally) → `aca sandboxgroup create --name <g> --location <region> --set-config` → `aca sandboxgroup role create --role "Container Apps SandboxGroup Data Owner" --principal-id $(az ad signed-in-user show --query id -o tsv)` → `aca doctor`. `--set-config` is required so subsequent `aca sandbox …` commands don't need `--group` on every call. Treat green `aca doctor` as the gate before doing anything else. Heads-up: `aca sandboxgroup create` already grants the Data Owner role to the calling principal, so the explicit `role create` is only needed when granting access to additional principals (use `--skip-role-check` on `create` if you want to defer).
Create a sandbox (imperative)	Minimum: `aca sandbox create --disk ubuntu`. Common knobs: `--cpu 2000m`, `--memory 4096Mi`, `--env "K=V"`, `--label name=dev --label role=worker` (repeatable; not `--labels`). Capture the printed ID into `SANDBOX_ID=$(aca sandbox create --disk ubuntu -o json \| jq -r .id)` for reuse. For config that should live in source control, use the manifest flow (see the row below) instead.
Apply / deploy a sandbox manifest	The full 3-command flow: `aca sandbox init` → `aca sandbox validate --file sandbox.yaml` → `aca sandbox apply --file sandbox.yaml`. Always `--file` (no `-f` short flag). State that the manifest pattern is the recommended path for CI/CD and reproducibility, in contrast to imperative `aca sandbox create`. If no manifest is present, run `aca sandbox init` — don't ask for a path.
Scaffold / generate a sandbox manifest	Run (or show) `aca sandbox init` to scaffold a starter `sandbox.yaml`. Mention the commonly edited fields (`disk`, `resources`, `lifecycle.autoSuspendPolicy`, `egressPolicy`, plus `ports`, `env`, `labels` as needed). Mention `aca sandbox schema` as the way to dump the JSON Schema for editor autocomplete.
Run a command or open a shell in a sandbox	Two distinct verbs: `aca sandbox exec --id "$SANDBOX_ID" -c "<command>"` for one-shot commands (returns stdout/stderr); `aca sandbox shell --id "$SANDBOX_ID"` for an interactive PTY. Anti-cue: `ssh` does not work — there is no SSH daemon inside the sandbox. `aca sandbox exec` / `shell` is the only path.
Delete a sandbox	`aca sandbox delete --id "$SANDBOX_ID" --yes`. Always recommend snapshotting first if there is any state worth preserving (`aca sandbox snapshot --id "$SANDBOX_ID" --name <snap>`) — delete is destructive. To delete by label selector: `aca sandbox list -l "name=<n>" -o json \| jq -r '.[].id' \| xargs -I{} aca sandbox delete --id {} --yes`.
Read / write / copy files in a sandbox	The `aca sandbox fs` family — `fs write --id "$SANDBOX_ID" --path /remote/p --file ./local` to upload, `fs cat --id "$SANDBOX_ID" --path /remote/p` to read, plus `fs ls / stat / mkdir / rm [--recursive]` for management. Don't suggest `scp` / `rsync` / shared filesystems — there is no SSH, and `fs` is the only data-plane file transport.
Expose a port — public preview (anonymous)	The two-step shape: `URL=$(aca sandbox port add --id "$SANDBOX_ID" --port <p> --anonymous -o json \| jq -r .url)`, then hit `$URL`. State explicitly that anonymous = anyone with the URL can reach it (public preview only). Remove with `aca sandbox port remove --id "$SANDBOX_ID" --port <p>`. For per-user gating use the Entra row below.
Expose a port with Entra auth (per-user gating)	`aca sandbox port add --id "$SANDBOX_ID" --port <p> --auth entra --allow-principal <user-object-id>`. Fetch the principal's object id with `az ad signed-in-user show --query id -o tsv` (or `az ad user show --id <upn> --query id -o tsv` for someone else). Pass `--allow-principal` once per principal you want to admit. Anti-cue: there is no `--email` flag — that's a stale shape; the supported gating is `--auth entra` + `--allow-principal <object-id>`.
Mount a shared volume	Two-step: (1) at the group: `aca sandboxgroup volume create --name <v> --type AzureBlob` (multi-attach, shared) or `--type DataDisk` (single-attach, high-perf block). (2) at the sandbox: `aca sandbox mount --id "$SANDBOX_ID" --volume <v> --path /mnt/<v>`. State that the volume lives at the group level; sandboxes attach it at runtime.
Lock down network egress (deny-default + allow-list)	The canonical form: `aca sandbox egress set --id "$SANDBOX_ID" --default Deny --rule ".github.com:Allow" --traffic-inspection Full`. Multiple `--rule "<pattern>:Allow"` flags accumulate. Inspect current policy with `aca sandbox egress show --id "$SANDBOX_ID"`. For production agent code, always recommend `--default Deny`* with an explicit `--rule` allow-list. Anti-cue: do not invent flags for individual IPs or block-lists, and not `--host-allow` — the only supported shape is `--default Deny
List / use a disk image	The canonical "what disks are available?" verb is `aca sandboxgroup disk list-public` (NOT `aca disks list`, which does not exist). Common presets include `ubuntu`, `debian`, `alpine`, `python`, `node`, `dotnet`, and `playwright`. To bake your own from an OCI image: `aca sandboxgroup disk create --image docker.io/library/alpine:3.19 --name <my-disk>`, then `aca sandbox create --disk-id <id>`. Flag distinction: `--disk` takes the public preset name; `--disk-id` takes the resource ID of a private/committed disk.
Suspend, resume, or set auto-suspend	Manual: `aca sandbox stop --id "$SANDBOX_ID"` suspends (preserves memory + disk); `aca sandbox resume --id "$SANDBOX_ID"` does sub-second restore. Idle policy: `aca sandbox lifecycle set --id "$SANDBOX_ID" --auto-suspend <seconds>` (default 300s = 5 min). State that suspended sandboxes incur storage cost only, no compute — this is the primary cost lever.
Snapshot / commit a sandbox	Per-sandbox: `aca sandbox snapshot --id "$SANDBOX_ID" --name <snap-name>`, then boot replicas with `aca sandbox create --snapshot <snap-name>`. Group-level CRUD: `aca sandboxgroup snapshot list / get / delete --selector "name=<snap-name>"`. Strongly recommend snapshotting BEFORE `aca sandbox delete` to preserve state. Always use `--name <snap-name>`, never `--image` (that is the wrong flag and will be rejected). Disk-only baking is `aca sandbox commit --id "$SANDBOX_ID" --name <disk-name>`.
Install the Python SDK	The SDK is published on PyPI as `azure-containerapps-sandbox`. Always preflight `uv` first — if it's missing, install it from the upstream installer, then install the SDK. Bash: `command -v uv >/dev/null 2>&1 \|\| curl -LsSf https://astral.sh/uv/install.sh \| sh; uv pip install azure-containerapps-sandbox`. PowerShell: `if (-not (Get-Command uv -ErrorAction SilentlyContinue)) { irm https://astral.sh/uv/install.ps1 \| iex }; uv pip install azure-containerapps-sandbox`. Import as `from azure_containerapps_sandbox import ...`. The SDK and the `aca` CLI are interchangeable surfaces over the same data plane — pick whichever fits your runtime (CLI for shells / agents, SDK for service code).
Compare the `aca` CLI vs the Azure portal	Both surfaces exist for sandbox groups. The portal lives at `https://containerapps.azure.com/sandbox-groups` and is good for visual inventory, role assignments, and ad-hoc inspection. The `aca` CLI is the authoritative scripting / automation surface — every `aca sandbox …` and `aca sandboxgroup …` verb is available there and is what CI/CD, agents, and reproducible workflows should use. Recommend portal for discovery and one-off ops, CLI for everything programmable.
Compare ACA Sandboxes vs Dynamic Sessions	Different products. ACA Sandboxes (`Microsoft.App/SandboxGroups`, the `aca` CLI) are hardware-isolated microVMs with snapshot/resume, shell/exec, port exposure, volumes, and egress policy — meant for long-running agent workloads, dev envs, MCP hosting, computer-use. Dynamic Sessions (`Microsoft.App/sessionPools`, the Sessions SDK) are short-lived Python/Node code-interpreter sandboxes meant for single-call LLM tool execution. If the user asks about Dynamic Sessions, redirect to those docs — do not answer with `aca` commands.
Anything in the "When NOT to use this skill" table below	A one-paragraph redirect to the right tool or official docs. Do NOT run the out-of-scope tool's commands. Do NOT walk through options. Do NOT ask follow-up questions about the out-of-scope tool. Bow out cleanly.
Vague / single-word prompts (`sandbox`, `microvm`, "I need a VM", "ephemeral VM for dev", "coding agent sandbox", "AI agent runtime")	Ask one clarifying question first before jumping into `aca sandbox create`. Disambiguate between: (a) coding agent / dev env in a sandbox, (b) AI agent runtime, (c) MCP hosting, (d) ephemeral VM-style dev box, (e) code interpreter. Then route to the matching row above. Premature commitment to `aca sandbox create` on a vague prompt is a failure.

When NOT to use this skill (hard reject + redirect)

If the user's task is not about ACA Sandboxes, refuse and redirect in one short reply — don't run any commands, don't walk through options, don't ask clarifying questions about the out-of-scope tool. The skill activated by mistake; bow out cleanly.

User asks about…	Reply pattern
`azd init`, `azd up`, `azd deploy`, project scaffolding	"That's the Azure Developer CLI (`azd`), not ACA Sandboxes. See the azd docs. Sandboxes don't have an `init`/`up`/`deploy` command and aren't a project bootstrapper."
`az acr build`, `docker build`, registry pushes	"That's Azure Container Registry / Docker, not ACA Sandboxes. See the `az acr` docs. Sandboxes consume disk images, not container images."
Cosmos / SQL / data-plane queries to other Azure services	"That's the relevant data service (Cosmos DB, Azure SQL, etc.), not ACA Sandboxes. Use that service's CLI / SDK / portal."
Listing Kubernetes pods, AKS cluster ops, `kubectl`	"That's AKS / Kubernetes, not ACA Sandboxes. Use `kubectl` or the AKS docs. Sandboxes are individual microVMs, not a Kubernetes cluster."
Deploying a Function App, App Service site, full Container App (Apps/Jobs)	"That's Azure Functions / App Service / Container Apps (apps and jobs), not Sandboxes. Use those products' deployment docs."

Never start running the out-of-scope tool's commands "just to help." A one-paragraph redirect is the correct, complete answer.

Get started

	Where
Install	references/install.md
Prerequisites	references/prerequisites.md
Quick start	references/quickstart.md
Full CLI reference	references/reference.md
Scenario recipes	references/scenarios.md

After install, always confirm setup with aca doctor — it resolves subscription / RG / group / region / role and tells you which check is red.

Try asking

Once the skill is loaded, paste any of these into your agent. Each one exercises a different capability — together they show the canonical shape for the most common sandbox tasks (and they double as a routing smoke test if you're testing changes to this skill).

Try saying	What you should get back
"install the aca cli"	the `aka.ms/aca-cli-install` one-liner + `aca --version` + auth-aware `az account show; az login only if it fails` + `aca doctor`
"set up a sandbox group from scratch"	the full 4-step bootstrap (group create + Data Owner role + `aca doctor` gate)
"create an ubuntu sandbox and run uname -a in it"	`aca sandbox create` with ID capture, then `aca sandbox exec`
"how do I ssh into my sandbox?"	corrective answer — no SSH daemon; use `aca sandbox shell` or `exec`
"copy data.csv into my sandbox"	`aca sandbox fs write --path … --file …` (and the anti-`scp` note)
"expose port 8080 publicly"	`aca sandbox port add --anonymous -o json \| jq -r .url`
"mount a shared volume on two sandboxes"	`aca sandboxgroup volume create --type AzureBlob` + `aca sandbox mount`
"restrict outbound traffic to github.com only"	`aca sandbox egress set --default Deny --rule "*.github.com:Allow"`
"snapshot my sandbox before I tear it down"	`aca sandbox snapshot --name <s>` followed by `aca sandbox delete --yes`
"suspend my sandbox to save money"	`aca sandbox stop`/`resume` plus `aca sandbox lifecycle set --auto-suspend`
"give me a YAML manifest for a 2 vCPU sandbox"	`aca sandbox init` → edit → `aca sandbox validate --file` → `aca sandbox apply --file`

Capabilities

Everything the platform exposes. Each row is the starting point — open references/reference.md for full flags and options.

Command rows below show only the shape. In real invocations:

every aca sandbox <verb> takes --id <sandbox-id>;

every aca sandboxgroup <noun> <verb> mutation takes --name <group> (or relies on the default group set via --set-config);

omit these from copies into the shell and you'll get a CLI parse error.

#	Capability	What it does	`aca` CLI
00	Sandbox groups	Provision, list/get, assign Data Owner role, tear down.	`aca sandboxgroup create / list / get / role create / delete`
01	Sandboxes	Create, list, get, delete; cpu/memory/labels/env; parallel.	`aca sandbox create / list / get / delete` (+ `--cpu --memory --label --env`)
02	Snapshots	Freeze a running sandbox; boot new ones from that point.	`aca sandbox snapshot --id <id> --name X` · `aca sandbox create --snapshot X`
03	Disks	Public disks, build from container image, commit a running sandbox.	`aca sandboxgroup disk list-public / create --image` · `aca sandbox commit --id <id> --name X` · `aca sandbox create --disk <public-name>` (or `--disk-id <id>` for private/committed disks)
04	Volumes	`AzureBlob` (shared) or `DataDisk` (block); mount at create or post-create.	`aca sandboxgroup volume create --type AzureBlob` · `aca sandbox mount --volume X --path /mnt/x`
05	Lifecycle	Stop/resume; auto-suspend after idle; auto-delete after TTL.	`aca sandbox stop / resume` · `aca sandbox lifecycle set --auto-suspend 60`
06	Ports	Expose an HTTP port; anonymous or Entra-gated (`--auth entra --allow-principal`); revoke.	`aca sandbox port add --port 8080 [--anonymous \| --auth entra --allow-principal <object-id>]` · `port list / remove`
07	Files	write / read / list / stat / mkdir / delete inside the sandbox.	`aca sandbox fs write --file ./local` · `fs cat / ls` · `fs cp <src> <dst>` (positional, `sbx-id:/path` syntax)
08	Egress	Deny-default outbound + host allow-list; audit decisions; YAML transforms.	`aca sandbox egress set --default Deny --rule "*.host.com:Allow"` · `egress show / decisions / apply`
09	Secrets	Group-scoped key/value, fetched at runtime from inside the sandbox.	`aca sandboxgroup secret set --name X --key K --value V` · `secret list / show / remove / delete`
10	Managed identity	System- or User-assigned MI on the group; grant RBAC for cross-group orchestration.	`aca sandboxgroup identity assign --system-assigned` (or `--user-assigned <res-id>`) · `identity show / remove`
11	Labels & selectors	`--label k=v` at create time (repeatable); AND-filter on list. Fleet management pattern.	`aca sandbox create --label role=worker --label tenant=t42` · `aca sandbox list -l role=worker`
12	Interactive shell	Real PTY into a running sandbox.	`aca sandbox shell --id <id>`
13	YAML spec / `apply`	Declarative infra-as-code: `init`, `validate`, `apply`, `schema`.	`aca sandbox init > sandbox.yaml` · `validate` · `apply --file sandbox.yaml`
14	`aca doctor`	Diagnose subscription / RG / group / region / role.	`aca doctor`

Scenarios

Composed patterns that combine the capabilities above. Full sketches in references/scenarios.md.

Web apps — start a server, expose a port anonymously, hit the URL.
Coding agents in a sandbox — run Copilot CLI / Claude Code / Codex with deny-default egress and (optionally) token-swap rules.
Code interpreter — LLM generates → exec → observe → iterate; snapshot between turns for rewind.
Swarms — orchestrator fans work across N worker sandboxes by label selector.
Sandbox inception — orchestrator runs inside a sandbox and uses its managed identity to drive a separate worker group. No credentials in agent code.
Computer-use — LLM drives a real browser; watch live via noVNC.
MCP hosting — host an MCP server in a sandbox; expose via port or Dev Tunnel.
Data processing — producer/consumer pipelines on shared AzureBlob volumes.
Developer workflows — PR builds, ephemeral CI, on-demand dev envs.

Python SDK — install + use

The Python SDK (azure-containerapps-sandbox) is the programmatic counterpart to the aca CLI and is in public preview. Install from PyPI (preflight uv first — install the upstream installer if it's missing):

# Linux / macOS
command -v uv >/dev/null 2>&1 || curl -LsSf https://astral.sh/uv/install.sh | sh
uv pip install azure-containerapps-sandbox

# Windows
if (-not (Get-Command uv -ErrorAction SilentlyContinue)) {
  irm https://astral.sh/uv/install.ps1 | iex
}
uv pip install azure-containerapps-sandbox

Import as:

from azure_containerapps_sandbox import SandboxGroupsClient

The SDK and the aca CLI are interchangeable surfaces over the same control plane — pick whichever fits your runtime (CLI for shells / agents / scripts, SDK for service code). When in doubt or for agent-driven self-installs, prefer the CLI install path above.