Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add softspark/ai-toolkit/plugin install ai-toolkitWrote 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/softspark/ai-toolkit/hook-creator)<a href="https://agentmods.dev/skills/softspark/ai-toolkit/hook-creator"><img src="https://agentmods.dev/badge/skills/softspark/ai-toolkit/hook-creator/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/softspark/ai-toolkit/hook-creator"><img src="https://agentmods.dev/badge/skills/softspark/ai-toolkit/hook-creator.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00049 | $0.02998 |
| Opus 5.5 | $0.00020 | $0.01199 |
| Sonnet 5.5 | $0.00010 | $0.00600 |
| Haiku 4.5 | $0.00005 | $0.00300 |
Grade A, and why
hook-creator 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 22d 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 — 235 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hook Creator
$ARGUMENTS
Create a new Claude Code hook following ai-toolkit conventions.
Supported Hook Events
Core lifecycle
| Event | Fires When | Matcher | Typical Use |
|---|---|---|---|
SessionStart |
Session begins, resumes, or clears | startup|resume|clear |
Context injection, rules reminder |
SessionEnd |
Session is closing | any | Flush logs, save transcripts |
UserPromptSubmit |
User submits a prompt | any | Prompt governance, usage tracking |
Notification |
Claude sends a notification | any | OS alerts, Slack pings |
MessageDisplay |
Assistant message text streams in completed-line batches | none | Return displayContent to replace the rendered batch without changing the transcript |
Tool lifecycle
| Event | Fires When | Matcher | Typical Use |
|---|---|---|---|
PreToolUse |
Before a tool executes | tool name (e.g. Bash) or if: rule |
Safety guards, validation, "defer" for headless |
PostToolUse |
After a tool executes | tool name | Feedback loops, logging, format-on-save |
PostToolUseFailure |
After a tool fails | tool name | Failure telemetry, recovery hints |
PostToolBatch |
After a batch of tool calls completes | any | Batch summaries, aggregate validation |
Turn lifecycle
| Event | Fires When | Matcher | Typical Use |
|---|---|---|---|
Stop |
Claude finishes responding | any | Quality checks, session save |
StopFailure |
Turn ends due to an API error (rate limit, auth) | any | Alerting, fallback behavior |
UserPromptExpansion |
Claude expands or rewrites a submitted prompt | any | Prompt policy and context shaping |
Subagent lifecycle
| Event | Fires When | Matcher | Typical Use |
|---|---|---|---|
SubagentStart |
Subagent launches | any | Observability |
SubagentStop |
Subagent completes | any | Result validation |
Compaction
| Event | Fires When | Matcher | Typical Use |
|---|---|---|---|
PreCompact |
Before context compaction; can block with exit 2 or {"decision":"block"} |
any | Context preservation |
PostCompact |
After compaction completes | any | Re-inject state that was summarized away |
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.
- 22d ago Changed · +15 lines db9574375262
- 1mo ago First seen · 220 lines · 49 tokens per session scan A ec2bcc395ef1
hook-creator is a skill published in the GitHub repository softspark/ai-toolkit (180 stars, last pushed yesterday), licensed Apache-2.0. It adds 49 tokens to every session and 2,998 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-03.
Other skills, from other repositories
cline-fix-volatile-msg
Ladder-aware Cline Anthropic caching — verify the rolling read/write ladder on the wire, then add the tools breakpoint and tune TTL. Updated for the 2026-08 AI-SDK monorepo.
continue-gemini-explicit
Continue's Gemini provider doesn't use the cachedContents API at all. Add explicit caching for sessions over the minimum token threshold.
roo-fix-volatile-msg
Ladder-aware Roo Code Anthropic caching — verify the rolling read/write ladder on the wire, then close the real gaps (Vertex 4-block budget, MiniMax path).
aider-1h-ttl
Aider uses 5min TTL by default and works around long pauses with keepalive pings. Wire up the 1h TTL beta instead.
cline-openai-cache-key
Cline OpenAI native provider sends no promptcachekey. Add a stable per-task key so cachedtokens stops being zero.
continue-enable-defaults
Continue's prompt caching is opt-in via config and off by default. Flip the default to systemAndTools.