Reference
Client SDK
Ruby

Ruby Client API

💡

Before going through this guide, make sure you follow the Oso Cloud Quickstart to get your Oso API Key properly set in your environment.

First, install the oso-cloud gem from RubyGems:


gem install oso-cloud

Instantiating an Oso Cloud Client

The Oso Cloud client provides an OsoCloud::Oso class that takes your Oso Cloud URL and API key:


require 'oso-cloud'
oso = OsoCloud::Oso.new(url: "https://cloud.osohq.com", api_key: YOUR_API_KEY)
# Later:
oso.tell("has_role", user, role, resource)
# Wherever authorization needs to be performed:
if oso.authorize(user, action, resource)
# Action is allowed

ℹ️

You should instantiate one client and share it across your application. Under the hood, it reuses connections to avoid paying the cost of negotiating a new connection on every request.

Specifying an Oso Fallback host

If you have deployed Oso Fallback nodes to your infrastructure, you may specify the host when instantiating the Oso Cloud client.


# Assumes Oso Fallback is hosted at http://localhost:8080
oso = OsoCloud::Oso.new(url: "https://cloud.osohq.com", api_key: YOUR_API_KEY, fallback_url: "http://localhost:8080")

Passing application entities into the client

Under the hood, Oso Cloud represents an entity in your application as a combination of a type and an ID, which together uniquely identify the entity. The Ruby client represents these entities using the OsoCloud::Value class, a struct with both type and id properties. For example:


alice = OsoCloud::Value.new(type: "User", id: "alice")
anvilsRepository = OsoCloud::Value.new(type: "Repository", id: "anvils")

You will pass objects like these into nearly every function call you make to the Ruby client.

Management API

Add fact: oso.tell(name, *args)

Adds a fact named name with the provided arguments. Example:


oso.tell(
"has_role",
OsoCloud::Value.new(type: "User", id: "bob"),
"owner",
OsoCloud::Value.new(type: "Organization", id: "acme")
)

ℹ️

For Oso Cloud developer accounts, bulk_tell, bulk_delete, and bulk calls are limited to 20 facts. If you attempt to send more than 20 facts, these functions will throw an error.

Add many facts: oso.bulk_tell([*[name, *args]])

Adds many facts at once. Example:


oso.bulk_tell([
[
"has_role",
OsoCloud::Value.new(type: "User", id: "bob"),
"owner"
OsoCloud::Value.new(type: "Organization", id: "acme")
],
[
"has_role",
OsoCloud::Value.new(type: "User", id: "bob"),
"maintainer",
OsoCloud::Value.new(type: "Repository", id: "anvils")
],
])

Delete fact: oso.delete(name, *args)

Deletes a fact. Does not throw an error if the fact is not found. Example:


oso.delete(
"has_role",
OsoCloud::Value.new(type: "User", id: "bob"),
"maintainer",
OsoCloud::Value.new(type: "Repository", id: "anvils")
)

Delete many facts: oso.bulk_delete([*[name, *args]])

Deletes many facts at once. Does not throw an error when some of the facts are not found. Example:


oso.bulk_delete([
[
"has_role",
OsoCloud::Value.new(type: "User", id: "bob"),
"owner",
OsoCloud::Value.new(type: "Organization", id: "acme")
],
[
"has_role",
OsoCloud::Value.new(type: "User", id: "bob"),
"maintainer",
OsoCloud::Value.new(type: "Repository", id: "anvils")
],
])

Transactionally delete and add facts: oso.bulk(delete: [*facts], tell: [*facts])

Deletes and adds many facts in one atomic transaction. The deletions are performed before the additions. nil can be used as a wildcard in facts in delete. Does not throw an error when the facts to delete are not found or when the facts to add already exist. Example:


oso.bulk(delete: [[
# All `has_role` facts linking User:bob and Repository:anvils will be deleted.
'has_role',
OsoCloud::Value.new(type: 'User', id: 'bob'),
nil,
OsoCloud::Value.new(type: 'Repo', id: 'anvils')
]],
insert: [[
# This fact will be added.
'has_role',
OsoCloud::Value.new(type: 'User', id: 'bob'),
'member',
OsoCloud::Value.new(type: 'Repo', id: 'anvils')
]])

List facts: oso.get(name, *args)

ℹ️

For Oso Cloud developer accounts, Get calls are limited to 1000 results. If you have more than 1000 facts, the function will throw an error.

Lists facts that are stored in Oso Cloud. Can be used to check the existence of a particular fact, or used to fetch all facts that have a particular argument:


# Get one fact:
oso.get(
"has_role",
OsoCloud::Value.new(type: "User", id: "bob")
"admin",
OsoCloud::Value.new(type: "Repository", id: "anvils")
)
# => [[
# "has_role",
# OsoCloud::Value.new(type: "User", id: "bob"),
# "admin",
# OsoCloud::Value.new(type: "Repository", id: "anvils")
# ]]
# List all roles on the `anvils` repo
oso.get("has_role", nil, nil, OsoCloud::Value.new(type: "Repository", id: "anvils"))
# => [
# [
# "has_role",
# OsoCloud::Value.new(type: "User", id: "bob"),
# "admin",
# OsoCloud::Value.new(type: "Repository", id: "anvils")
# ],
# ... other has_role facts
#]

Note that nil behaves like a wildcard: passing nil, nil, anvils means "find all facts where anvils is the third argument, regardless of other arguments".

Check API

ℹ️

For Oso Cloud developer accounts, * the number of context facts per request is limited to 20; and * the number of records returned is limited to 1000.

Context facts

You may provide an array of context facts as an optional argument to any of the Check API methods. When Oso Cloud performs a check, it will consider these context facts in addition to any other facts you've previously added. Context facts are only used in the API call in which they're provided— they do not persist across requests. Learn more about context facts.

Check a permission: oso.authorize(actor, action, resource)

Determines whether or not an action is allowed, based on a combination of authorization data and policy logic. Example:


alice = OsoCloud::Value.new(type: "User", id: "alice")
anvils_repository = OsoCloud::Value.new(type: "Repository", id: "anvils")
raise "Action is not allowed" unless oso.authorize(alice, "read", anvils_repository)

You may provide an array of context facts as an optional fourth argument to this method. Example:


issue_on_anvils_repository = OsoCloud::Value.new(type: "Repository", id: "anvils-1")
oso.authorize(alice, "read", anvils_repository, [
["has_relation", issue_on_anvils_repository, "parent", anvils_repository] # a context fact
])

Check authorized resources: oso.authorize_resources(actor, action, resources)

Returns a subset of resources on which an actor can perform a particular action. Ordering and duplicates, if any exist, are preserved.

ℹ️

For Oso Cloud developer accounts, the number of input resources is limited to 1000.

Example:


alice = OsoCloud::Value.new(type: "User", id: "alice")
anvils_repository = OsoCloud::Value.new(type: "Repository", id: "anvils")
acme_repository = OsoCloud::Value.new(type: "Repository", id: "acme")
resources = oso.authorize_resources(alice, "read", [anvils_repository, acme_repository])
# => [acme_repository]

You may provide an array of context facts as an optional fourth argument to this method. Example:


issue_on_acme_repository = OsoCloud::Value.new(type: "Repository", id: "acme-1")
issue_on_anvils_repository = OsoCloud::Value.new(type: "Repository", id: "anvils-2")
oso.authorize_resources(
alice, "read", [issue_on_anvils_repository, issue_on_acme_repository],
[ # context facts
["has_relation", issue_on_anvils_repository, "parent", anvils_repository],
["has_relation", issue_on_acme_repository, "parent", acme_repository]
]
)
# => [issue_on_acme_repository]

List authorized resources: oso.list(actor, action, resource_type)

Fetches a list of resource ids on which an actor can perform a particular action. Example:


alice = OsoCloud::Value.new(type: "User", id: "alice")
oso.list(alice, "read", "Repository")
# => ["acme"]

You may provide an array of context facts as an optional fourth argument to this method. Example:


anvils_repository = OsoCloud::Value.new(type: "Repository", id: "anvils")
acme_repository = OsoCloud::Value.new(type: "Repository", id: "acme")
issue_on_acme_repository = OsoCloud::Value.new(type: "Repository", id: "acme-1")
issue_on_anvils_repository = OsoCloud::Value.new(type: "Repository", id: "anvils-2")
oso.list(
alice, "read", "Issue",
[ # context facts
["has_relation", issue_on_anvils_repository, "parent", anvils_repository],
["has_relation", issue_on_acme_repository, "parent", acme_repository]
]
)
# => ["acme-1"]

List authorized actions: oso.actions(actor, resource)

Fetches a list of actions which an actor can perform on a particular resource. Example:


alice = OsoCloud::Value.new(type: "User", id: "alice")
acme_repository = OsoCloud::Value.new(type: "Repository", id: "acme")
oso.actions(alice, acme_repository)
# => ["read"]

You may provide an array of context facts as an optional third argument to this method. Example:


issue_on_acme_repository = OsoCloud::Value.new(type: "Repository", id: "acme-1")
oso.actions(
alice, issue_on_acme_repository,
[
["has_relation", issue_on_acme_repository, "parent", acme_repository] # a context fact
]
)
# => ["read"]

Query for anything: oso.query(rule)

Query Oso Cloud for any predicate and any combination of concrete and wildcard arguments. Unlike oso.get, which only lists facts you've added, you can use oso.query to list derived information about any rule in your policy. Example:


# Query for all the repos `User:bob` can `read`
oso.query("allow",
OsoCloud::Value.new(type: "User", id: "bob"),
"read",
OsoCloud::Value.new(type: "Repository")
)
# => [
# [ "allow", #<struct OsoCloud::Value type="User", id="bob">, "read", #<struct OsoCloud::Value type="Repo", id="acme"> ],
# [ "allow", #<struct OsoCloud::Value type="User", id="bob">, "read", #<struct OsoCloud::Value type="Repo", id="anvils"> ]
# ]
# Query for all the objects `User:admin` can `read`
oso.query("allow",
OsoCloud::Value.new(type: "User", id: "admin"),
"read",
nil
)
# => [
# # `User:admin` can `read` anything
# [ "allow", #<struct OsoCloud::Value type="User", id="admin">, "read", nil ]
# ]
# Query for all the repos `User:bob` can `write` derived from context facts
oso.query("allow",
OsoCloud::Value.new(type: "User", id: "bob"),
"write",
OsoCloud::Value.new(type: "Repository"),
context_facts: [
[ "has_permission", OsoCloud::Value.new(type: "User", id: "bob"), "write", OsoCloud::Value.new(type: "Repository", id: "anvils")]
]
)
# => [
# [ "allow", #<struct OsoCloud::Value type="User", id="bob">, "write", #<struct OsoCloud::Value type="Repo", id="anvils"> ],
# ]

Note that nil behaves like a wildcard. Passing "allow", nil, nil, anvils means "find anyone who can do anything to anvils". nil also behaves like a wildcard in return values from oso.query. Additionally, if you want to query over all instances of a particular type, pass a dictionary with a "type" key but no "id" key. For example, "allow", bob, "read", OsoCloud::Value.new(type: "Repository") will query for all the objects of type "Repository" that bob can read.

Learn more about how to query Oso Cloud.

Policy API

Update the active policy: oso.policy(policy)

Updates the policy in Oso Cloud. The string passed into this method should be written in Polar. Example:


oso.policy("actor User {}")

This command will run any tests defined in your policy. If one or more of these tests fail, your policy will not be updated.

Talk to an Oso Engineer

If you'd like to learn more about using Oso Cloud in your app or have any questions about this guide, schedule a 1x1 with an Oso engineer. We're happy to help.

Get started with Oso Cloud →

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