Emit Claude Code plugin hint on CLI invocations

[dmerand]

What

Emit the Claude Code plugin hint for the Shopify AI Toolkit from the all-command oclif prerun hook:

<claude-code-hint v="1" type="plugin" value="shopify-ai-toolkit@claude-plugins-official" />

The hint is written to stderr only when CLAUDECODE or CLAUDE_CODE_CHILD_SESSION is truthy. The emitter is private, and failures are swallowed so the optional integration cannot break a CLI command.

Why

This lets Claude Code suggest Shopify's AI Toolkit plugin to users who run the CLI under Claude Code. Emission happens on every invocation because Claude Code owns deduplication and persistence; a client-side once-ever gate could lose the only useful prompt in a session.

The oclif prerun hook does not run for early exits such as --help, --version, or parse errors, so those paths do not emit.

[github-actions]

Differences in type declarations

We detected differences in the type declarations generated by Typescript for this branch compared to the baseline ('main' branch). Please, review them to ensure they are backward-compatible. Here are some important things to keep in mind:

• Some seemingly private modules might be re-exported through public modules.
• If the branch is behind main you might see odd diffs, rebase main into this branch.

New type declarations

packages/cli-kit/dist/private/node/plugin-hints.d.ts

/** The Claude Code plugin hint protocol marker. */
export declare const SHOPIFY_AI_TOOLKIT_PLUGIN_HINT = "<claude-code-hint v=\"1\" type=\"plugin\" value=\"shopify-ai-toolkit@claude-plugins-official\" />";
/**
 * Returns whether this process was launched by Claude Code.
 *
 * @param environment - Environment variables to inspect.
 * @returns Whether Claude Code environment markers are truthy.
 */
export declare function runningUnderClaudeCode(environment?: NodeJS.ProcessEnv): boolean;
/**
 * Emits the Claude Code plugin hint on every command invocation under Claude Code.
 * Claude Code handles deduplication and persistence. A failed optional integration
 * must not make the user's command fail.
 *
 * @param environment - Environment variables to inspect.
 */
export declare function emitClaudeCodePluginHint(environment?: NodeJS.ProcessEnv): void;

Existing type declarations

We found no diffs with existing type declarations

[teddyhwang]

Interesting, is this a Claude Code feature?

[Copilot]

Pull request overview

Adds an optional integration to emit a Claude Code “plugin hint” marker to stderr during Shopify CLI invocations when Claude Code environment markers are present, enabling Claude Code to recommend the Shopify AI Toolkit plugin.

Changes:

• Emit the Claude Code plugin hint from the global oclif prerun hook (best-effort; failures swallowed).
• Introduce a private plugin-hints module to detect Claude Code and write the hint marker to stderr.
• Add unit + integration tests covering detection, emission, and failure-to-load behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
packages/cli-kit/src/public/node/hooks/prerun.ts	Calls the private hint emitter during prerun for every resolved command invocation.
packages/cli-kit/src/public/node/hooks/prerun.integration.test.ts	Verifies prerun writes the marker under Claude Code and remains resilient to emitter import failures.
packages/cli-kit/src/private/node/plugin-hints.ts	Implements detection and stderr emission of the Claude Code plugin hint marker.
packages/cli-kit/src/private/node/plugin-hints.test.ts	Unit tests for environment detection and hint emission behavior.

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[dmerand]

Interesting, is this a Claude Code feature?

​Yes, I should have linked to these docs in the description: https://code.claude.com/docs/en/plugin-hints