Dynamic Context Injection (@mention & /commands)

Problem

While layered configuration files provide good baseline context, agents often need specific pieces of information (e.g., contents of a particular file, output of a script, predefined complex prompt) on-demand during an interactive session. Constantly editing static context files or pasting large chunks of text into prompts is inefficient.

Solution

Implement mechanisms for users to dynamically inject context into the agent's working memory during a session. Common approaches include:

• File/Folder At-Mentions: Allowing users to type a special character (e.g., @) followed by a file or folder path (e.g., @src/components/Button.tsx or @app/tests/). The agent then ingests the content of the specified file or a summary of the folder into its current context for the ongoing task.
• Custom Slash Commands: Enabling users to define reusable, named prompts or instructions in separate files (e.g., in ~/.claude/commands/foo.md). These can be invoked with a slash command (e.g., /user:foo), causing their content to be loaded into the agent's context. This is useful for frequently used complex instructions or context snippets.

These methods allow for a more fluid and efficient way to provide targeted context exactly when needed.

Example (context injection flow)

References

• Based on the at-mention and slash command features described in "Mastering Claude Code: Boris Cherny's Guide & Cheatsheet," section IV.

Source