docs: rename the agent kit kind to sandbox

Rename the spec.yaml kind: agent value to kind: sandbox and the "agent
kit" concept to "sandbox kit" across the overview, spec reference,
examples, index, and FAQ. Update the "Agent kits" heading and its
#agent-kits anchor to "Sandbox kits"/#sandbox-kits, and repoint inbound
links. The agent: block and the build-an-agent.md tutorial keep their
existing names.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dvdksn

content/manuals/ai/sandboxes/customize/_index.md

@@ -40,12 +40,12 @@ dependencies — anything you'd rather not reinstall on every sandbox start.
 
 A kit is a YAML artifact applied at sandbox creation. The kit can run
 install commands, drop files into the sandbox, declare network and
-credential rules, and (for agent kits) define which template image the
+credential rules, and (for sandbox kits) define which template image the
 agent runs in. Use kits for things that vary per agent or per team:
 shared linter config, project-specific install steps, credential
 injection for a service the agent talks to.
 
-Templates and kits work together. An agent kit's `agent.image` field
+Templates and kits work together. A sandbox kit's `agent.image` field
 points at a template: the template provides the base environment, the
 kit layers config, secrets, and runtime behavior on top. A team can ship
 one heavy template and several thin kits without rebuilding the image
@@ -58,7 +58,7 @@ each time something changes.
 | Pre-install tools and packages into a reusable base image | [Template](templates.md)                                      |
 | Capture a configured running sandbox for reuse            | [Saved template](templates.md#saving-a-sandbox-as-a-template) |
 | Add a tool, credential, or config to agent runs via YAML  | [Kit (mixin)](kits.md)                                        |
-| Define a new agent from scratch                           | [Kit (agent)](kits.md#define-an-agent)                        |
+| Define a new agent from scratch                           | [Kit (sandbox)](kits.md#define-an-agent)                      |
 
 Templates and kits can be used together. A template bakes heavy tools into
 the image for fast sandbox startup; a kit layered on top adds per-run
@@ -67,4 +67,4 @@ credentials, config, or extra capabilities.
 ## Tutorials
 
 - [Build your own agent kit](build-an-agent.md) — step-by-step walkthrough
-  for packaging [Amp](https://ampcode.com/) as an agent kit.
+  for packaging [Amp](https://ampcode.com/) as a sandbox kit.

content/manuals/ai/sandboxes/customize/build-an-agent.md

@@ -72,7 +72,7 @@ attaches.
 
 ```yaml {title="amp/spec.yaml"}
 schemaVersion: "1"
-kind: agent
+kind: sandbox
 name: amp
 displayName: Amp
 description: The frontier coding agent.
@@ -176,7 +176,7 @@ Putting it all together:
 
 ```yaml {title="amp/spec.yaml"}
 schemaVersion: "1"
-kind: agent
+kind: sandbox
 name: amp
 displayName: Amp
 description: The frontier coding agent.

content/manuals/ai/sandboxes/customize/kit-examples.md

@@ -1,7 +1,7 @@
 ---
 title: Kit examples
 linkTitle: Examples
-description: Copy-and-adapt spec.yaml snippets for common mixin and agent kit patterns — static files, install commands, background services, initFiles, Claude Code skills, and agent forks.
+description: Copy-and-adapt spec.yaml snippets for common mixin and sandbox kit patterns — static files, install commands, background services, initFiles, Claude Code skills, and agent forks.
 keywords: sandboxes, sbx, kits, mixins, examples, patterns, skills
 weight: 25
 ---
@@ -253,15 +253,15 @@ idempotent. The heredoc pattern overwrites cleanly each time.
 
 ## Fork an existing agent
 
-Agent kits (`kind: agent`) define a full agent from scratch. The most
+Sandbox kits (`kind: sandbox`) define a full agent from scratch. The most
 common variant is a fork of a built-in agent — same image and
 credentials, but a different entrypoint. This example reproduces the
 built-in `claude` agent but drops `--dangerously-skip-permissions` so
 every tool call prompts for approval:
 
 ```yaml {title="claude-safe/spec.yaml"}
 schemaVersion: "1"
-kind: agent
+kind: sandbox
 name: claude-safe
 displayName: Claude Code (with approval prompts)
 description: Claude Code without --dangerously-skip-permissions
@@ -296,7 +296,7 @@ Launch with the kit's `name:` as the agent argument to `sbx run`:
 $ sbx run claude-safe --kit ./claude-safe
 ```
 
-For a step-by-step walkthrough of building a new agent kit from
+For a step-by-step walkthrough of building a new sandbox kit from
 scratch, see [Build an agent](build-an-agent.md).
 
 ## More examples

content/manuals/ai/sandboxes/customize/kit-reference.md

@@ -31,21 +31,21 @@ my-kit/
 
 ```yaml
 schemaVersion: "1"
-kind: <mixin | agent>
+kind: <mixin | sandbox>
 name: <name>
 displayName: <name>
 description: <text>
 ```
 
-| Field           | Required | Description                                                              |
-| --------------- | -------- | ------------------------------------------------------------------------ |
-| `schemaVersion` | Yes      | Spec schema version. Set to `"1"`.                                       |
-| `kind`          | Yes      | `mixin` for kits that extend an agent; `agent` for kits that define one. |
-| `name`          | Yes      | Unique identifier. Lowercase, alphanumeric, hyphens.                     |
-| `displayName`   | No       | Human-readable name.                                                     |
-| `description`   | No       | Short description.                                                       |
+| Field           | Required | Description                                                                |
+| --------------- | -------- | -------------------------------------------------------------------------- |
+| `schemaVersion` | Yes      | Spec schema version. Set to `"1"`.                                         |
+| `kind`          | Yes      | `mixin` for kits that extend an agent; `sandbox` for kits that define one. |
+| `name`          | Yes      | Unique identifier. Lowercase, alphanumeric, hyphens.                       |
+| `displayName`   | No       | Human-readable name.                                                       |
+| `description`   | No       | Short description.                                                         |
 
-The sections below apply to both kinds. Agent kits also declare an
+The sections below apply to both kinds. Sandbox kits also declare an
 [`agent:` block](#agent-block).
 
 ## Credentials
@@ -271,11 +271,11 @@ agentContext: |
   <markdown>
 ```
 
-Top-level field. Available in both mixin and agent kits. Markdown
+Top-level field. Available in both mixin and sandbox kits. Markdown
 appended to the agent's memory file at sandbox creation. The agent reads
 this content at startup. Write it as instructions or notes the agent
 should follow when working in the sandbox. Applied only when the active
-agent kit sets [`agent.aiFilename`](#agent-block).
+sandbox kit sets [`agent.aiFilename`](#agent-block).
 
 The file is written to the parent of the workspace path inside the
 sandbox, not to the workspace itself. For a workspace mounted at
@@ -295,7 +295,7 @@ across files instead of being concatenated into the main one:
 
 ## Agent block
 
-Required for `kind: agent`.
+Required for `kind: sandbox`.
 
 ```yaml
 agent:

content/manuals/ai/sandboxes/customize/kits.md

@@ -29,11 +29,11 @@ and enforces them at runtime. Credentials stay on the host and go through
 a proxy instead of entering the VM, and outbound traffic is restricted to
 the domains permitted by the kit's network rules.
 
-A kit is either a mixin or an agent:
+A kit is either a mixin or a sandbox:
 
 - Mixin kits (`kind: mixin`) extend an existing agent with extra
   capabilities. Stack several on the same sandbox.
-- Agent kits (`kind: agent`) define a full agent from scratch: its image,
+- Sandbox kits (`kind: sandbox`) define a full agent from scratch: its image,
   entrypoint, network policies, and everything else the agent needs.
 
 ## What kits can do
@@ -208,8 +208,8 @@ agentContext: |
   Shared config lives at `/workspace/ruff.toml`.
 ```
 
-Both mixin and agent kits can declare `agentContext:`. The content is written
-only when the active agent kit sets [`agent.aiFilename`](kit-reference.md#agent-block),
+Both mixin and sandbox kits can declare `agentContext:`. The content is written
+only when the active sandbox kit sets [`agent.aiFilename`](kit-reference.md#agent-block),
 which determines the memory file's name.
 
 When more than one loaded kit declares an `agentContext:` block, each kit's
@@ -231,7 +231,7 @@ See [`agentContext`](kit-reference.md#agent-context) in the spec reference for t
 
 ### Define an agent
 
-Agent kits declare an `agent:` block with the image the agent runs in and
+Sandbox kits declare an `agent:` block with the image the agent runs in and
 the command the user attaches to when they launch the sandbox:
 
 ```yaml
@@ -241,7 +241,7 @@ agent:
     run: [my-agent, "--yolo"]
 ```
 
-See [Agent kits](#agent-kits) for use cases and an example.
+See [Sandbox kits](#sandbox-kits) for use cases and an example.
 
 ## Mixin kits
 
@@ -307,17 +307,17 @@ To apply the mixin to a sandbox that's already running, use
 [`sbx kit add`](#local) instead. The `--kit` flag only takes effect when a
 sandbox is created.
 
-## Agent kits
+## Sandbox kits
 
-An agent kit defines a full agent from scratch — image, entrypoint, and
+A sandbox kit defines a full agent from scratch — image, entrypoint, and
 everything the agent needs. Common use cases:
 
 - Package a custom agent you've built so others can run it
 - Ship a team-internal agent with defaults baked in
 - Run a fork of an existing agent with your own config
 - Prototype a new agent integration
 
-Agent kits declare everything a mixin kit can, plus an
+Sandbox kits declare everything a mixin kit can, plus an
 [`agent:` block](kit-reference.md#agent-block) that tells the sandbox how to launch the
 agent. For a step-by-step walkthrough, see
 [Build your own agent kit](build-an-agent.md).
@@ -330,7 +330,7 @@ with network, credentials, environment, and commands:
 
 ```yaml {title="claude/spec.yaml"}
 schemaVersion: "1"
-kind: agent
+kind: sandbox
 name: claude
 agent:
   image: "docker/sandbox-templates:claude-code-docker"

content/manuals/ai/sandboxes/faq.md

@@ -111,13 +111,13 @@ startup. In Claude Code, use the `/permissions` command to change the mode
 interactively.
 
 To make approval prompts the default for every session, define a custom
-agent kit that overrides the agent's entrypoint to drop the
+sandbox kit that overrides the agent's entrypoint to drop the
 permission-skipping flag. For example, a kit that launches Claude Code
 without `--dangerously-skip-permissions`:
 
 ```yaml {title="claude-safe/spec.yaml"}
 schemaVersion: "1"
-kind: agent
+kind: sandbox
 name: claude-safe
 agent:
   image: "docker/sandbox-templates:claude-code-docker"
@@ -126,7 +126,7 @@ agent:
 ```
 
 Run it with `sbx run claude-safe --kit ./claude-safe/`. See
-[Agent kits](customize/kits.md#agent-kits) for the full pattern.
+[Sandbox kits](customize/kits.md#sandbox-kits) for the full pattern.
 
 ## How do I know if my agent is running in a sandbox?