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/yz5e/agent-skills/forgenpx skills add yz5e/agent-skills --skill forgegit clone --depth 1 https://github.com/yz5e/agent-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/yz5e/agent-skills/forge)<a href="https://agentmods.dev/skills/yz5e/agent-skills/forge"><img src="https://agentmods.dev/badge/skills/yz5e/agent-skills/forge.svg" alt="Measured on agentmods" height="20"></a>What 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 | $0.00000 | $0.05354 |
| Opus 5 | $0.00000 | $0.02677 |
| Sonnet 5 | $0.00000 | $0.01071 |
| Haiku 4.5 | $0.00000 | $0.00535 |
Grade A, and why
forge 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 406 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/forge
Interview the user with structured multiple-choice questions, then forge a prompt that another agent session can execute with minimal ambiguity. Targets Claude Opus 4.7 or GPT-5.5 (Codex CLI). Use this skill for coding and agentic prompt design, anywhere from a single bug-fix prompt to a long-horizon repo migration.
The skill has three phases: interview, draft, deliver.
Read references/anthropic-claude-prompting.md when targeting Opus 4.7 and the task is long-horizon, tool-heavy, or expensive enough that prompt quality materially matters. Read references/openai-gpt-5-5-prompting.md when targeting GPT-5.5 or Codex.
Activation
Two ways to invoke:
- Bare:
/forge. Open with "What do you need a prompt for?" and treat the user's reply as the seed. - Seeded:
/forge <topic>. Use the topic as the interview seed, skip the opening question, and dive into clarifications.
The skill also activates conversationally when the user says things like "help me write a prompt", "I need an Opus 4.7 prompt", "scope this for me", or asks for prompt design. When activated conversationally, treat the user's most recent message as the seed.
Run /forge in the main session, never in a forked subagent. Subagents cannot relay user replies in either Claude Code or Codex, so the interview will hang.
Phase 1: Interview
Run an adaptive interview. Pick the transport based on the harness, then start with up to 5 base questions. Add deeper questions only when answers flag complexity (long-horizon, tool-heavy, subagent-orchestrated, validation-heavy, multi-system).
Interview transport
The skill ships in two harnesses with different interaction primitives. Detect which is available and pick the matching transport. Never invent a tool that is not in your toolset.
- Claude Code (any mode, including outside plan mode): use the
AskUserQuestiontool. Up to 4 questions per call, 2 to 4 options each, header max 12 chars. An "Other" free-text choice is available by setting the per-question option that displays an additional free-text choice after the listed options. - Codex CLI / Codex app, and any harness without
AskUserQuestion: use the text fallback below. Codex does not expose a multi-choice modal to skills or custom prompts. The selection modals you see in the Codex Mac app are wired to built-in slash commands (/plan,/model,/agentetc.), not to user code, so the skill cannot trigger them. It renders questions as plain text and waits for the user's reply.
What ships with it
2 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.
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.
- 4d ago First seen · 406 lines · 0 tokens per session scan A 336012bd1bc9
forge is a skill published in the GitHub repository yz5e/agent-skills (16 stars, last pushed 4mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 5,354 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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