cerul

cerul is a skill for Claude Code from cerul-ai/cerul. It costs 30 tokens per session (243 once invoked), scanned A, original, Apache-2.0.

Instructions for using Cerul, a command-line tool that finds evidence in videos and other long-form media. It supports searching an authorized library and answering questions with timestamps and artifact links.

In plain words
What is it for?
Use it to search approved media libraries, answer questions about their contents, and present supporting timestamps and links.
Why use it?
It avoids guessing what was said or shown in media and keeps answers tied to retrieved evidence.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the cerul plugin — 1 skill shipped together

Good fit Use it to search approved media libraries, answer questions about their contents, and present supporting timestamps and links.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/cerul-ai/cerul/cerul
Install

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.

Any agent
npx skills add cerul-ai/cerul --skill cerul
Clone the repo
git clone --depth 1 https://github.com/cerul-ai/cerul

Made for: Claude Code.

Or install cerul, the plugin that ships this one along with the rest of its 1 skill.

Wrote 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.

agentmods badge for cerul

README.md
[![agentmods](https://agentmods.dev/badge/skills/cerul-ai/cerul/cerul.svg)](https://agentmods.dev/skills/cerul-ai/cerul/cerul)
Your own site
<a href="https://agentmods.dev/skills/cerul-ai/cerul/cerul"><img src="https://agentmods.dev/badge/skills/cerul-ai/cerul/cerul.svg" alt="Measured on agentmods" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 243 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00030 $0.00243
Opus 5 $0.00015 $0.00121
Sonnet 5 $0.00006 $0.00049
Haiku 4.5 $0.00003 $0.00024

Measured 8d ago against content hash f4e966e45ab6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

cerul 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 8d 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.

integrations/claude-code/plugins/cerul/skills/cerul/SKILL.md · 32 lines

What it actually says

Cerul

Use the public cerul CLI when the answer depends on video or other indexed long-form media. Do not guess what a speaker said.

Before a request, run cerul capabilities so unavailable capabilities are not invented. For retrieval, use a user-authorized scope:

cerul search "query" --library-id library_...

For a grounded answer using the constrained Agent facade:

cerul ask "question" --library-id library_...

Never print, request in chat, or persist API keys or installation tokens. If authentication is missing, tell the user to configure CERUL_API_KEY, or the local CERUL_BASE_URL plus CERUL_INSTALLATION_TOKEN, outside the conversation.

Do not expand the requested library or asset scope. Do not change a local-only execution policy. Present Evidence timestamps and Artifact links from the response; do not fabricate citations.

Changes

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.

  1. 8d ago First seen · 32 lines · 30 tokens per session scan A f4e966e45ab6

Subscribe to this mod's changes

cerul is a skill published in the GitHub repository cerul-ai/cerul (156 stars, last pushed 9d ago), licensed Apache-2.0. It adds 30 tokens to every session and 243 once invoked, about $0.0002 per session on Opus 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 2026-08-30.

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