Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/ronmkr/promptbook/command-developmentnpx skills add ronmkr/PromptBook --skill command-developmentgit clone --depth 1 https://github.com/ronmkr/PromptBookWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00100 | $0.04341 |
| Opus 5 | $0.00050 | $0.02171 |
| Sonnet 5 | $0.00020 | $0.00868 |
| Haiku 4.5 | $0.00010 | $0.00434 |
Grade A, and why
command-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
89% identical to command-development — 161 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 885 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Command Development for Antigravity
Note: The
.gemini/commands/directory is a legacy format. For new skills, use the.gemini/skills/<name>/SKILL.mddirectory format. Both are loaded identically — the only difference is file layout. See theskill-developmentskill for the preferred format.
Overview
Slash commands are frequently-used prompts defined as Markdown files that Gemini executes during interactive sessions. Understanding command structure, frontmatter options, and dynamic features enables creating powerful, reusable workflows.
Key concepts:
- Markdown file format for commands
- YAML frontmatter for configuration
- Dynamic arguments and file references
- Bash execution for context
- Command organization and namespacing
Command Basics
What is a Slash Command?
A slash command is a Markdown file containing a prompt that Gemini executes when invoked. Commands provide:
- Reusability: Define once, use repeatedly
- Consistency: Standardize common workflows
- Sharing: Distribute across team or projects
- Efficiency: Quick access to complex prompts
Critical: Commands are Instructions FOR Gemini
Commands are written for agent consumption, not human consumption.
When a user invokes /command-name, the command content becomes Gemini's instructions. Write commands as directives TO Gemini about what to do, not as messages TO the user.
Correct approach (instructions for Gemini):
Review this code for security vulnerabilities including:
- SQL injection
- XSS attacks
- Authentication issues
Provide specific line numbers and severity ratings.
Incorrect approach (messages to user):
This command will review your code for security issues.
You'll receive a report with vulnerability details.
The first example tells Gemini what to do. The second tells the user what will happen but doesn't instruct Gemini. Always use the first approach.
Command Locations
Project commands (shared with team):
What ships with it
10 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- examples/plugin-commands.md 14 KB
- examples/simple-commands.md 8.5 KB
- README.md 7.5 KB
- references/advanced-workflows.md 13 KB
- references/documentation-patterns.md 15 KB
- references/frontmatter-reference.md 8.9 KB
- references/interactive-commands.md 20 KB
- references/marketplace-considerations.md 16 KB
- references/plugin-features-reference.md 14 KB
- references/testing-strategies.md 14 KB
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 885 lines · 100 tokens per session scan A 6f40b9205f9a
command-development is a skill published in the GitHub repository ronmkr/PromptBook (2 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 100 tokens to every session and 4,341 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. It is 89% identical to command-development, differing in 161 lines, and is treated as a copy.
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