sealed-secrets

sealed-secrets is a skill for Claude Code from ashfulcra/fulcra-tools. It costs 49 tokens per session (6,550 once invoked), scanned A, original, MIT.

A procedure for storing credentials in encrypted form so other agents can share the stored package without seeing the secrets. It also checks whether an unlocked credential still works, rather than only whether it can be decrypted.

In plain words
What is it for?
Use it to seal, unlock, rotate, and verify credentials kept in a shared object store.
Why use it?
It helps a replacement machine recover credentials safely after a container or host is rebuilt, while avoiding treating revoked credentials as valid.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter. Also seen: mentions Codex; built for openclaw.

Good fit Use it to seal, unlock, rotate, and verify credentials kept in a shared object store.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ashfulcra/fulcra-tools/sealed-secrets
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 ashfulcra/fulcra-tools --skill sealed-secrets
Clone the repo
git clone --depth 1 https://github.com/ashfulcra/fulcra-tools

Made for: Claude Code.

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 sealed-secrets

README.md
[![agentmods](https://agentmods.dev/badge/skills/ashfulcra/fulcra-tools/sealed-secrets/github.svg)](https://agentmods.dev/skills/ashfulcra/fulcra-tools/sealed-secrets)
Your own site
<a href="https://agentmods.dev/skills/ashfulcra/fulcra-tools/sealed-secrets"><img src="https://agentmods.dev/badge/skills/ashfulcra/fulcra-tools/sealed-secrets/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.

agentmods 80×15 button for sealed-secrets

Your own site · 80×15
<a href="https://agentmods.dev/skills/ashfulcra/fulcra-tools/sealed-secrets"><img src="https://agentmods.dev/badge/skills/ashfulcra/fulcra-tools/sealed-secrets.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,550 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 warn 7 Sept 2026
SkillSpector: 2 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Data Exfiltration · line 109
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 449
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 $0.00049 $0.06550
Opus 5 $0.00024 $0.03275
Sonnet 5 $0.00010 $0.01310
Haiku 4.5 $0.00005 $0.00655

Measured 9d ago against content hash 6295e33154eb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

sealed-secrets 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 9d 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.

skills/sealed-secrets/SKILL.md · 530 lines

How it starts

The opening of the file, as written. The whole thing — 530 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Sealed Secrets

A successor session on a fresh machine must be able to recover the role's credentials — and must never be told a revoked one is fine.

Agents lose their machines. Containers get reclaimed, hosts are rebuilt from snapshots, a session resumes tomorrow on hardware that has never seen your config. Everything else an agent needs can live in a shared object store. Its credentials cannot — not in the clear, because the store is readable by every agent on the team and by whoever operates it.

So seal them. The store carries ciphertext; the operator carries one passphrase; the successor runs one command and learns, per secret, whether it actually works.

A decrypt that succeeds is not a credential that authenticates.

That sentence is the whole design. A bundle that decrypts perfectly to a revoked token passes every cryptographic check and still leaves the successor dead.

Where to start — the re-entrancy probes

Run in order; enter at the first probe that fails. Every state below is safe to re-enter: sealing is a new bundle version, unlocking is read-only, and verifying makes no writes at all.

Probe (run in order) Command Passes when If it fails, enter at
1. Role has a bundle pointer read the role's charter frontmatter a sealed_bundle: key is present and non-empty §1 Seal
2. Bundle object exists read the path that key names the read returns an object (not absent, not an error) §1 Seal — the pointer is dangling
3. Envelope parses parse it as JSON it has schema, wraps (non-empty list), payload §1 Seal — re-seal; do not hand-edit
4. You can open it run the unlock command it prints a per-secret table, no crypto errors §2 Unlock
5. The secrets WORK read that same table every secret reads VERIFIED §3 When verify fails

Probe 5 is the only one that matters to the caller. Probes 1-4 can all pass on a bundle full of revoked credentials. Never report "unlocked" as success; report the verify table.

Read the full file on GitHub · 530 lines

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. 9d ago First seen · 530 lines · 49 tokens per session scan A 6295e33154eb

Subscribe to this mod's changes

sealed-secrets is a skill published in the GitHub repository ashfulcra/fulcra-tools (10 stars, last pushed today), licensed MIT. It adds 49 tokens to every session and 6,550 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 2026-08-31.