RBACX

Universal RBAC/ABAC/ReBAC policy engine for Python with a clean core, policy sets, a compact condition DSL (including time ops), and adapters for common web frameworks.

Features

• Algorithms: deny-overrides (default), permit-overrides, first-applicable
• Conditions: ==, !=, <, <=, >, >=, contains, in, hasAll, hasAny, startsWith, endsWith, before, after, between
• Explainability: decision, reason, rule_id/last_rule_id, obligations
• Policy sets: combine multiple policies with the same algorithms
• Hot reload: file/HTTP/S3 sources with ETag and a polling manager
• Types & lint: mypy-friendly core, Ruff-ready

Installation

pip install rbacx

Quickstart

from rbacx import Action, Context, Guard, Subject, Resource

policy = {
    "algorithm": "deny-overrides",
    "rules": [
        {
            "id": "doc_read",
            "effect": "permit",
            "actions": ["read"],
            "resource": {"type": "doc", "attrs": {"visibility": ["public", "internal"]}},
            "condition": {"hasAny": [ {"attr": "subject.roles"}, ["reader", "admin"] ]},
            "obligations": [ {"type": "require_mfa"} ]
        },
        {"id": "doc_deny_archived", "effect": "deny", "actions": ["*"],
         "resource": {"type": "doc", "attrs": {"archived": True}}}
    ],
}

g = Guard(policy)

d = g.evaluate_sync(
    subject=Subject(id="u1", roles=["reader"]),
    action=Action("read"),
    resource=Resource(type="doc", id="42", attrs={"visibility": "public"}),
    context=Context(attrs={"mfa": True}),
)

assert d.allowed is True
assert d.effect == "permit"
print(d.reason, d.rule_id)  # "matched", "doc_read"

Decision schema

• decision: "permit" or "deny"
• reason: one of "matched", "explicit_deny", "action_mismatch", "condition_mismatch", "condition_type_mismatch", "resource_mismatch", "no_match", "obligation_failed"
• rule_id and last_rule_id (both included for compatibility; last_rule_id is the matched rule id)
• policy_id (present for policy sets; None for single policies)
• obligations: list passed to the obligation checker (if a permit was gated)
• (optional) challenge: present when an authentication/step-up is required (e.g., for MFA); may be used to return 401 with the appropriate challenge header

Policy sets

Default algorithm is:

from rbacx.core.policyset import decide as decide_policyset

policyset = {"algorithm":"deny-overrides", "policies":[ policy, {"rules":[...]} ]}
result = decide_policyset(policyset, {"subject":..., "action":"read", "resource":...})

If you want to test, try this:

from rbacx.core.policyset import decide as decide_policyset

# example set of policies
policyset = {
    "algorithm": "deny-overrides",
    "policies": [
        {"rules": [
            {"id": "allow_public_read", "effect": "permit", "actions": ["read"],
             "resource": {"type": "doc", "attrs": {"visibility": ["public"]}}}
        ]},
        {"rules": [
            {"id": "deny_archived", "effect": "deny", "actions": ["*"],
             "resource": {"type": "doc", "attrs": {"archived": True}}}
        ]},
    ],
}

# example request
req = {
    "subject": {"id": "u1", "roles": ["reader"]},
    "action": "read",
    "resource": {"type": "doc", "id": "42", "attrs": {"visibility": "public", "archived": False}},  # can try: would be `deny` if archived `True`
    "context": {},
}

res = decide_policyset(policyset, req)
print(res.get("decision", res))  # -> "permit"

Hot reloading

Default algorithm is:

from rbacx import Guard, HotReloader
from rbacx.store import FilePolicySource

guard = Guard(policy={})
mgr = HotReloader(guard, FilePolicySource("policy.json"), initial_load=...)
mgr.check_and_reload()        # initial load
mgr.start(10)  # background polling thread

If you want to test, try this:

⚠️ Important: this example creates a file on disk. You also can rewrite it with TempFile (tempfile.NamedTemporaryFile)

import json
import time
from rbacx import Action, Context, Guard, HotReloader, Resource, Subject
from rbacx.store import FilePolicySource

# create a tiny policy file next to the script
policy_path = "policy.json"
json.dump({
    "algorithm": "deny-overrides",
    "rules": [{
        "id": "allow_public_read", "effect": "permit", "actions": ["read"],
        "resource": {"type": "doc", "attrs": {"visibility": ["public"]}}
    }]
}, open(policy_path, "w", encoding="utf-8"))

guard = Guard({})
mgr = HotReloader(guard, FilePolicySource(policy_path), initial_load=True)
mgr.check_and_reload()  # initial load

print(guard.evaluate_sync(
    subject=Subject(id="u1", roles=["reader"]),
    action=Action("read"),
    resource=Resource(type="doc", id="1", attrs={"visibility": "public"}),
    context=Context(),
).effect)  # -> "permit"

# update policy and wait 3 second for reload
json.dump({
    "algorithm": "deny-overrides",
    "rules": [{"id": "deny_all", "effect": "deny", "actions": ["*"], "resource": {"type": "doc"}}]
}, open(policy_path, "w", encoding="utf-8"))
mgr.start(3)  # starting polling
time.sleep(3)

print(guard.evaluate_sync(
    subject=Subject(id="u1", roles=["reader"]),
    action=Action("read"),
    resource=Resource(type="doc", id="1", attrs={"visibility": "public"}),
    context=Context(),
).effect)  # -> "deny"

Quick links

• 📌 Deprecation Policy
• 🛡️ API Stability Guarantees
• 🔐 Security Policy
• 🤝 Code of Conduct

Packaging

• We ship py.typed so type checkers pick up annotations.
• Standard PyPA flow: python -m build, then twine upload to (Test)PyPI.

License

MIT