Policy Storage

Policy storage in Casbin is handled by adapters. The enforcer loads and (optionally) saves policy through the adapter API.

Loading policy from a CSV file

Using a CSV file is the simplest option and works well for development and examples.

Example: examples/rbac_policy.csv

p, alice, data1, read
p, bob, data2, write
p, data2_admin, data2, read
p, data2_admin, data2, write
g, alice, data2_admin

nota

If a field contains commas, wrap it in double quotes:

p, alice, "data1,data2", read    --correct
p, alice, data1,data2, read        --incorrect (the whole phrase "data1,data2" should be wrapped in double quotes)

If a field contains both commas and double quotes, wrap it in double quotes and escape internal quotes by doubling them:

p, alice, data, "r.act in (""get"", ""post"")"        --correct
p, alice, data, "r.act in ("get", "post")"            --incorrect (you should use "" to escape "")

See casbin#886.

Adapter API

Method	Type	Description
LoadPolicy()	basic	Load all policy rules from the storage
SavePolicy()	basic	Save all policy rules to the storage
AddPolicy()	optional	Add a policy rule to the storage
RemovePolicy()	optional	Remove a policy rule from the storage
RemoveFilteredPolicy()	optional	Remove policy rules that match the filter from the storage

Database Storage Format

Example policy (CSV)

p, data2_admin, data2, read
p, data2_admin, data2, write
g, alice, admin

Typical database layout (e.g. MySQL)

id	ptype	v0	v1	v2	v3	v4	v5
1	p	data2_admin	data2	read
2	p	data2_admin	data2	write
3	g	alice	admin

Columns

• id — Primary key (adapter-specific; not part of Casbin policy).
• ptype — Policy type: p, g, g2, etc.
• v0–v5 — Policy fields in order (left to right in CSV). Most adapters use 6 columns; some support more. Check the adapter docs if you need extra fields.

For full adapter API and design details, see Adapters.