A guide for adding role-based access control to an API. It covers declaring permissions, granting them to roles, checking them on routes, and finding the resource IDs a caller may access.

Use it when adding or changing a permission, role grant, route permission check, or the list of resources visible to a caller.

It prevents permission names and role rules from being duplicated or checked inconsistently. It also keeps feature services from reading access-control tables directly.

How bayesimpact/bayes-platform configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to bayesimpact/bayes-platform. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/bayesimpact/bayes-platform/main/.claude/skills/rbac/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/bayesimpact/bayes-platform

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/bayesimpact/bayes-platform/rbac/github.svg)](https://agentmods.dev/skills/bayesimpact/bayes-platform/rbac)

Your own site

<a href="https://agentmods.dev/skills/bayesimpact/bayes-platform/rbac"><img src="https://agentmods.dev/badge/skills/bayesimpact/bayes-platform/rbac/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/bayesimpact/bayes-platform/rbac"><img src="https://agentmods.dev/badge/skills/bayesimpact/bayes-platform/rbac.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,854 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.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00052	$0.01854
Opus 5.5	$0.00021	$0.00742
Sonnet 5.5	$0.00010	$0.00371
Haiku 4.5	$0.00005	$0.00185

Measured 3d ago against content hash 33d8c18ad319, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

rbac 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 3d 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.

.claude/skills/rbac/SKILL.md · 123 lines

How it starts

The opening of the file, as written. The whole thing — 123 lines — stays where its author put it; the contents beside it link to each section on GitHub.

RBAC

Permissions are declared once, granted on roles in the catalog, checked on the route, and used to list what the caller can see. Do not query role_grant or role_permission from a feature service.

This skill explains how to use the model. It does not replace:

.cursor/rules/permission-matrix.mdc — keep docs/rbac-permission-matrix.md in sync
.claude/skills/check-permission-matrix/SKILL.md — audit that the matrix matches the catalog
ADR 0019 — why the model is shaped this way

1. Declare the permission

In packages/api-contracts/src/rbac/permissions.ts, add one string constant. This file is the only place a permission string is declared.

export const PROJECT_ARCHIVE_PERMISSION = "project.archive" as const

If the permission is global (no resource id), add it to the GlobalPermission union in the same file.

Import the constant into apps/api/src/domains/rbac/rbac.constants.ts and re-export it from the existing export block. Do not redeclare the string there.

Add a one-line entry to PERMISSION_DESCRIPTIONS in that file.

2. Grant it on a role

Add the constant to the role arrays that should hold it:

ORGANIZATION_ROLE_PERMISSIONS — org roles, and the global platform_staff / platform_superadmin roles
PROJECT_ROLE_PERMISSIONS
AGENT_ROLE_PERMISSIONS
REVIEW_CAMPAIGN_ROLE_PERMISSIONS, for review_campaign_tester and review_campaign_reviewer, held on review_campaign rows

Org roles do not grant project.read. Project visibility comes from a project membership, or from a review campaign role on one of the project's campaigns (see below), unless a parent role is explicitly given the requested key.

If PermissionService.listResourceIds or listResourcePermissions must accept the new key, add it to READ_PERMISSION_RESOURCE_TYPE_MAP. Only keys in that map are valid listing permissions (organization.read, project.read, agent.read, and the matching backoffice.*.read keys).

Read the full file on GitHub · 123 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.

3d ago Changed 33d8c18ad319
6d ago Changed 8b71abd875eb
14d ago Changed 0c8be240e9c1
20d ago Changed · +5 lines 06e783958733
1mo ago First seen · 118 lines · 52 tokens per session scan A fe9d68050520

Subscribe to this mod's changes

rbac is a skill published in the GitHub repository bayesimpact/bayes-platform (23 stars, last pushed yesterday), licensed MIT. It adds 52 tokens to every session and 1,854 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 2026-09-30.