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/nylo-core/claude-code/nylo-authnpx skills add nylo-core/claude-code --skill nylo-authgit clone --depth 1 https://github.com/nylo-core/claude-codeWhat 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 | $0.00044 | $0.02409 |
| Opus 5 | $0.00022 | $0.01205 |
| Sonnet 5 | $0.00009 | $0.00482 |
| Haiku 4.5 | $0.00004 | $0.00241 |
Grade A, and why
nylo-auth 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.
How it starts
The opening of the file, as written. The whole thing — 395 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Nylo Authentication
Overview
Nylo v7 authentication is managed through the Auth class, which stores user session data securely and syncs it to Backpack (an in-memory key-value store) for fast synchronous access. It supports multiple named sessions, token management, and integrates with the router for authenticated routes.
When to Use
- Implementing login/logout flows
- Storing and retrieving auth tokens
- Checking if a user is authenticated
- Updating stored auth data (e.g., token refresh)
- Managing multiple auth sessions (user, device, admin)
- Setting up routes that require authentication
- Generating unique device identifiers
- When NOT to use: For general-purpose key-value storage unrelated to auth, use nylo-storage instead
Quick Reference
| Action | Code |
|---|---|
| Authenticate user | await Auth.authenticate(data: user) |
| Get all auth data | Auth.data() |
| Get specific field | Auth.data(field: 'token') |
| Check if authenticated | await Auth.isAuthenticated() |
| Update auth data | await Auth.set((data) { data['token'] = newToken; return data; }) |
| Logout | await Auth.logout() |
| Logout all sessions | await Auth.logoutAll(sessions: ['device', 'admin']) |
| Sync to Backpack | await Auth.syncToBackpack() |
| Get device ID | await Auth.deviceId() |
| Set authenticated route | router.add(HomePage.path).authenticatedRoute() |
| Navigate to auth route | routeToAuthenticatedRoute() |
Auth.authenticate()
Stores user session data. Accepts a Map, a Model instance, or no data (timestamp only):
// Store a Map
await Auth.authenticate(data: {
"token": "ey2sdm...",
"userId": 123,
"email": "[email protected]",
});
// Store a Model instance
User user = User(id: 123, email: "[email protected]", token: "ey2sdm...");
await Auth.authenticate(data: user);
// Authenticate with no data (stores timestamp only)
await Auth.authenticate();
// Named session
await Auth.authenticate(
data: {"deviceToken": "abc123"},
session: 'device',
);
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 · 395 lines · 44 tokens per session scan A 49fa3b2d0331
nylo-auth is a skill published in the GitHub repository nylo-core/claude-code (4 stars, last pushed 4mo ago), licensed MIT. It adds 44 tokens to every session and 2,409 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.
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