[sandbox-cli] Surface coding agent shortcuts in help and skill

.changeset/agent-help-example.md

@@ -0,0 +1,5 @@
+---
+"sandbox": patch
+---
+
+Show a coding agent launch example first in the top-level CLI help.

packages/sandbox/docs/index.md

@@ -30,6 +30,10 @@ Commands:
 
 Examples:
 
+– Start a coding agent in a sandbox
+
+  $ sandbox create opencode
+
 – Create a sandbox on a Secure Compute network (requires an Enterprise plan)
 
   $ sandbox create --network-id your_network_id_here

packages/sandbox/src/app.ts

@@ -48,6 +48,10 @@ export const app = (opts?: { withoutAuth?: boolean; appName?: string }) => {
       }),
     },
     examples: [
+      {
+        description: "Start a coding agent in a sandbox",
+        command: `${appName} create opencode`,
+      },
       {
         description:
           "Create a sandbox on a Secure Compute network (requires an Enterprise plan)",

skills/sandbox/SKILL.md

@@ -987,6 +987,12 @@ sandbox create --region <region>             # Defaults to iad1; any Vercel regi
 sandbox create --failover-regions <region>,<region>  # Comma-separated
 sandbox create --failover-regions none               # No failover, overrides the project default
 
+# Start a coding agent (interactive terminal required)
+sandbox create opencode
+sandbox create pi
+sandbox create claude
+sandbox create codex
+
 # Fork an existing sandbox (inherits config, incl. env; --env replaces it)
 sandbox fork <source>
 sandbox fork <source> --name my-fork --vcpus 4 --env FOO=1
@@ -1047,6 +1053,14 @@ sandbox config network-policy <name> --network-policy deny-all
 sandbox config tags <name> --tag env=prod
 ```
 
+Agent shortcuts use the universal image and require an interactive terminal.
+Do not combine them with `--image`, `--runtime`, or `--snapshot`. Configure
+authentication for the agent separately from `sandbox login`.
+
+Exiting the agent leaves the sandbox running. Unless you pass `--silent`, the CLI
+prints reconnect and stop commands. Follow any environment-variable reminder
+printed with the reconnect command.
+
 ## Common Patterns
 
 ### Dev Server Pattern (Persistent)