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/agentfront/frontmcp/frontmcp-authoritiesnpx skills add agentfront/frontmcp --skill frontmcp-authoritiesgit clone --depth 1 https://github.com/agentfront/frontmcpWrote 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/agentfront/frontmcp/frontmcp-authorities)<a href="https://agentmods.dev/skills/agentfront/frontmcp/frontmcp-authorities"><img src="https://agentmods.dev/badge/skills/agentfront/frontmcp/frontmcp-authorities.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 | $0.00165 | $0.05156 |
| Opus 5 | $0.00082 | $0.02578 |
| Sonnet 5 | $0.00033 | $0.01031 |
| Haiku 4.5 | $0.00016 | $0.00516 |
Grade A, and why
frontmcp-authorities 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 5d 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 — 415 lines — stays where its author put it; the contents beside it link to each section on GitHub.
FrontMCP Authorities
Built-in RBAC/ABAC/ReBAC authorization system for FrontMCP entry types. Each flow has native checkEntryAuthorities and filterByAuthorities stages that enforce access control policies declared via the authorities field on entry decorators. Configured via @FrontMcp({ authorities: { claimsMapping, profiles, scopeMapping } }) — no plugin needed. Flow stages handle enforcement, and developers can hook into them with Will, Did, and Around decorators. Supports named profiles for reuse, JWT claims mapping for any identity provider, inline policies with roles/permissions/attributes/relationships, and composable combinators (allOf, anyOf, not).
When to Use This Skill
Must Use
- Adding role-based or permission-based access control to tools, resources, prompts, or skills
- Restricting MCP entry visibility based on the caller's JWT claims
- Enforcing tenant isolation (ABAC) or relationship checks (ReBAC) on entries
- Gating which skills a caller can discover and load (
@Skill({ authorities }))
Recommended
- Setting up a multi-tenant server where different tenants see different tools
- Building an admin vs. user distinction across your MCP surface
- Combining multiple authorization models (e.g., RBAC + ABAC) on the same entry
Skip When
- You only need authentication (login/token validation) without authorization (see
frontmcp-config/configure-auth) - You are building a public server with no access restrictions (use
mode: 'public') - You need OAuth scopes at the transport level, not entry-level policies (see
configure-auth-modes)
Decision: Use this skill whenever you need to control who can access which entries based on roles, permissions, attributes, or relationships.
CRITICAL: Ask About JWT Shape First
Before writing any authorities configuration, the coding agent MUST ask the developer:
"What identity provider (IdP) are you using, and what does your JWT payload look like? I need to know where roles, permissions, and tenant ID are located in the claims."
What ships with it
4 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.
- 5d ago First seen · 415 lines · 165 tokens per session scan A b6cd60fbb093
frontmcp-authorities is a skill published in the GitHub repository agentfront/frontmcp (146 stars, last pushed 3d ago), licensed Apache-2.0. It adds 165 tokens to every session and 5,156 once invoked, about $0.0008 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.
Other skills, from other repositories
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auth-patterns
Use when implementing authentication (JWT, sessions, OAuth), authorization (RBAC, ABAC), password hashing, MFA, or security best practices for backend services.
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Guides the design and assessment of RBAC and ABAC authorization models against the NIST RBAC model (Sandhu et al.) and NIST SP 800-162 (ABAC guide). Auto-invoked when designing role hierarchies, evaluating permission boundaries, implementing ABAC policy patterns, performing role mining, or preventing role explosion.…
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build-and-test
Build the Wassette workspace and run its test suite with the just recipes — debug and release builds, example and test components, and the combined unit plus documentation tests. Use when compiling Wassette, building example components, or running and debugging tests.