Configuration

Configuration parameters can be provided via:

Using Configuration Reloading you can modify the parameters without restarting the server.

Minimum parameters

The server is able to start without any config parameters, but it won’t be able to serve requests unless it has a role to serve anonymous requests with - or a secret to use for JWT authentication.

Config File

There is no predefined location for the config file, you must specify the file path as the one and only argument to the server:

./postgrest /path/to/postgrest.conf

The configuration file must contain a set of key value pairs:

# postgrest.conf

# The standard connection URI format, documented at
# https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING
db-uri       = "postgres://user:pass@host:5432/dbname"

# The database role to use when no client authentication is provided.
# Should differ from authenticator
db-anon-role = "anon"

# The secret to verify the JWT for authenticated requests with.
# Needs to be 32 characters minimum.
jwt-secret           = "reallyreallyreallyreallyverysafe"
jwt-secret-is-base64 = false

# Port the postgrest process is listening on for http requests
server-port = 3000

You can run postgrest --example to display all possible configuration parameters and how to use them in a configuration file.

Environment Variables

Environment variables are capitalized, have a PGRST_ prefix, and use underscores. For example: PGRST_DB_URI corresponds to db-uri and PGRST_APP_SETTINGS_* to app.settings.*.

libpq environment variables are also supported for constructing the connection string, see db-uri.

See the full list of environment variable names on List of parameters.

In-Database Configuration

You can also configure the server with database settings by using a pre-config function. For example, you can configure db-schemas and jwt-secret like this:

# postgrest.conf

db-pre-config  = "postgrest.pre_config"

# or env vars

PGRST_DB_PRE_CONFIG = "postgrest.pre_config"
-- create a dedicated schema, hidden from the API
create schema postgrest;
-- grant usage on this schema to the authenticator
grant usage on schema postgrest to authenticator;

-- the function can configure postgREST by using set_config
create or replace function postgrest.pre_config()
returns void as $$
  select
      set_config('pgrst.db_schemas', 'schema1, schema2', true)
    , set_config('pgrst.jwt_secret', 'REALLYREALLYREALLYREALLYVERYSAFE', true);
$$ language sql;

Note that underscores(_) need to be used instead of dashes(-) for the in-database config parameters. See the full list of in-database names on List of parameters.

You can disable the in-database configuration by setting db-config to false.

Note

For backwards compatibility, you can do in-db config by modifying the authenticator role. This is no longer recommended as it requires SUPERUSER.

ALTER ROLE authenticator SET pgrst.db_schemas = "tenant1, tenant2, tenant3"
ALTER ROLE authenticator IN DATABASE <your_database_name> SET pgrst.db_schemas = "tenant4, tenant5" -- database-specific setting, overrides the previous setting

Configuration Reloading

It’s possible to reload PostgREST’s configuration without restarting the server. You can do this via signal or via notification.

Reload with signal

To reload the configuration via signal, send a SIGUSR2 signal to the server process.

killall -SIGUSR2 postgrest

Reload with NOTIFY

To reload the configuration from within the database, you can use a NOTIFY command.

NOTIFY pgrst, 'reload config'

The "pgrst" notification channel is enabled by default. You can name the channel with db-channel and enable or disable it with db-channel-enabled.

List of parameters

admin-server-port

Type

Int

Default

n/a

Reloadable

N

Environment

PGRST_ADMIN_SERVER_PORT

In-Database

n/a

Specifies the port for the Health Check endpoints.

app.settings.*

Type

String

Default

n/a

Reloadable

&

Environment

PGRST_APP_SETTINGS_*

In-Database

n/a

Arbitrary settings that can be used to pass in secret keys directly as strings, or via OS environment variables. For instance: app.settings.jwt_secret = "$(MYAPP_JWT_SECRET)" will take MYAPP_JWT_SECRET from the environment and make it available to PostgreSQL functions as current_setting('app.settings.jwt_secret').

db-aggregates-enabled

Type

Boolean

Default

False

Reloadable

Y

Environment

PGRST_DB_AGGREGATES_ENABLED

In-Database

pgrst.db_aggregates_enabled

When this is set to true, the use of Aggregate Functions is allowed.

It is recommended that this be set to false unless proper safeguards are in place to prevent potential performance problems from arising. For example, it is possible that a user may request the max() of an unindexed column in a table with millions of rows. At best, this would result in a slow query, and at worst, it could be abused to prevent other users from accessing your API (i.e. a form of denial-of-service attack.)

Proper safeguards could include:

db-anon-role

Type

String

Default

n/a

Reloadable

Y

Environment

PGRST_DB_ANON_ROLE

In-Database

pgrst.db_anon_role

The database role to use when executing commands on behalf of unauthenticated clients. For more information, see Overview of role system.

When unset anonymous access will be blocked.

db-channel

Type

String

Default

pgrst

Reloadable

Y

Environment

PGRST_DB_CHANNEL

In-Database

n/a

The name of the notification channel that PostgREST uses for Schema Cache Reloading and configuration reloading.

db-channel-enabled

Type

Boolean

Default

True

Reloadable

Y

Environment

PGRST_DB_CHANNEL_ENABLED

In-Database

n/a

When this is set to true, the notification channel specified in db-channel is enabled.

You should set this to false when using PostgresSQL behind an external connection pooler such as PgBouncer working in transaction pooling mode. See this section for more information.

db-config

Type

Boolean

Default

True

Reloadable

Y

Environment

PGRST_DB_CONFIG

In-Database

n/a

Enables the in-database configuration.

db-pre-config

Type

String

Default

n/a

Reloadable

Y

Environment

PGRST_DB_PRE_CONFIG

In-Database

pgrst.db_pre_config

Name of the function that does In-Database Configuration.

db-extra-search-path

Type

String

Default

public

Reloadable

Y

Environment

PGRST_DB_EXTRA_SEARCH_PATH

In-Database

pgrst.db_extra_search_path

Extra schemas to add to the search_path of every request. These schemas tables, views and functions don’t get API endpoints, they can only be referred from the database objects inside your db-schemas.

This parameter was meant to make it easier to use PostgreSQL extensions (like PostGIS) that are outside of the db-schemas.

Multiple schemas can be added in a comma-separated string, e.g. public, extensions.

db-max-rows

Type

Int

Default

Reloadable

Y

Environment

PGRST_DB_MAX_ROWS

In-Database

pgrst.db_max_rows

For backwards compatibility, this config parameter is also available without prefix as “max-rows”.

A hard limit to the number of rows PostgREST will fetch from a view, table, or function. Limits payload size for accidental or malicious requests.

db-plan-enabled

Type

Boolean

Default

False

Reloadable

Y

Environment

PGRST_DB_PLAN_ENABLED

In-Database

pgrst.db_plan_enabled

When this is set to true, the execution plan of a request can be retrieved by using the Accept: application/vnd.pgrst.plan header. See Execution plan.

db-pool

Type

Int

Default

10

Reloadable

N

Environment

PGRST_DB_POOL

In-Database

n/a

Number of maximum connections to keep open in PostgREST’s database pool.

db-pool-acquisition-timeout

Type

Int

Default

10

Reloadable

N

Environment

PGRST_DB_POOL_ACQUISITION_TIMEOUT

In-Database

n/a

Specifies the maximum time in seconds that the request will wait for the pool to free up a connection slot to the database.

db-pool-max-idletime

Type

Int

Default

30

Reloadable

N

Environment

PGRST_DB_POOL_MAX_IDLETIME

In-Database

n/a

For backwards compatibility, this config parameter is also available as “db-pool-timeout”.

Time in seconds to close idle pool connections.

db-pool-max-lifetime

Type

Int

Default

1800

Reloadable

N

Environment

PGRST_DB_POOL_MAX_LIFETIME

In-Database

n/a

Specifies the maximum time in seconds of an existing connection in the pool.

db-pool-automatic-recovery

Type

Boolean

Default

True

Reloadable

Y

Environment

PGRST_DB_POOL_AUTOMATIC_RECOVERY

In-Database

n/a

Enables or disables connection retrying.

When disabled, PostgREST would terminate immediately after connection loss instead of retrying indefinitely. See this section for more information.

db-pre-request

Type

String

Default

n/a

Reloadable

Y

Environment

PGRST_DB_PRE_REQUEST

In-Database

pgrst.db_pre_request

For backwards compatibility, this config parameter is also available without prefix as “pre-request”.

A schema-qualified function name to call right after the Transaction-Scoped Settings are set. See Pre-Request.

db-prepared-statements

Type

Boolean

Default

True

Reloadable

Y

Environment

PGRST_DB_PREPARED_STATEMENTS

In-Database

pgrst.db_prepared_statements

Enables or disables prepared statements.

When disabled, the generated queries will be parameterized (invulnerable to SQL injection) but they will not be prepared (cached in the database session). Not using prepared statements will noticeably decrease performance, so it’s recommended to always have this setting enabled.

You should only set this to false when using PostgresSQL behind an external connection pooler such as PgBouncer working in transaction pooling mode. See this section for more information.

db-root-spec

Type

String

Default

n/a

Reloadable

Y

Environment

PGRST_DB_ROOT_SPEC

In-Database

pgrst.db_root_spec

Function to override the OpenAPI response. See Overriding Full OpenAPI Response.

db-schemas

Type

String

Default

public

Reloadable

Y

Environment

PGRST_DB_SCHEMAS

In-Database

pgrst.db_schemas

For backwards compatibility, this config parameter is also available in singular as “db-schema”.

The list of database schemas to expose to clients. See Schemas.

db-tx-end

Type

String

Default

commit

Reloadable

N

Environment

PGRST_DB_TX_END

In-Database

n/a

Specifies how to terminate the database transactions.

# The transaction is always committed
db-tx-end = "commit"

# The transaction is committed unless a "Prefer: tx=rollback" header is sent
db-tx-end = "commit-allow-override"

# The transaction is always rolled back
db-tx-end = "rollback"

# The transaction is rolled back unless a "Prefer: tx=commit" header is sent
db-tx-end = "rollback-allow-override"

db-uri

Type

String

Default

postgresql://

Reloadable

N

Environment

PGRST_DB_URI

In-Database

n/a

The standard PostgreSQL connection string, there are different ways to specify it:

URI Format

"postgres://authenticator:mysecretpassword@localhost:5433/postgres?parameters=val"
  • Under this format symbols and unusual characters in the password or other fields should be percent encoded to avoid a parse error.

  • If enforcing an SSL connection to the database is required you can use sslmode in the URI, for example postgres://user:pass@host:5432/dbname?sslmode=require.

  • The user with whom PostgREST connects to the database is also known as the authenticator role. For more information see Overview of role system.

  • When running PostgREST on the same machine as PostgreSQL, it is also possible to connect to the database using a Unix socket and the Peer Authentication method as an alternative to TCP/IP communication and authentication with a password, this also grants higher performance. To do this you can omit the host and the password, e.g. postgres://user@/dbname, see the libpq connection string documentation for more details.

Keyword/Value Format

"host=localhost port=5433 user=authenticator password=mysecretpassword dbname=postgres"

LIBPQ Environment Variables

PGHOST=localhost PGPORT=5433 PGUSER=authenticator PGDATABASE=postgres

Any parameter that is not set in the above formats is read from libpq environment variables. The default connection string is postgresql://, which reads all parameters from the environment.

External config file

Choosing a value for this parameter beginning with the at sign such as @filename (e.g. @./configs/my-config) loads the connection string out of an external file.

jwt-aud

Type

String

Default

n/a

Reloadable

Y

Environment

PGRST_JWT_AUD

In-Database

pgrst.jwt_aud

Specifies the JWT audience claim. If this claim is present in the client provided JWT then you must set this to the same value as in the JWT, otherwise verifying the JWT will fail.

Warning

Using this setting will only reject tokens with a different audience claim. Tokens without audience claim will still be accepted.

jwt-role-claim-key

Type

String

Default

.role

Reloadable

Y

Environment

PGRST_JWT_ROLE_CLAIM_KEY

In-Database

pgrst.jwt_role_claim_key

For backwards compatibility, this config parameter is also available without prefix as “role-claim-key”.

A JSPath DSL that specifies the location of the role key in the JWT claims. This can be used to consume a JWT provided by a third party service like Auth0, Okta or Keycloak. Usage examples:

# {"postgrest":{"roles": ["other", "author"]}}
# the DSL accepts characters that are alphanumerical or one of "_$@" as keys
jwt-role-claim-key = ".postgrest.roles[1]"

# {"https://www.example.com/role": { "key": "author }}
# non-alphanumerical characters can go inside quotes(escaped in the config value)
jwt-role-claim-key = ".\"https://www.example.com/role\".key"

jwt-secret

Type

String

Default

n/a

Reloadable

Y

Environment

PGRST_JWT_SECRET

In-Database

pgrst.jwt_secret

The secret or JSON Web Key (JWK) (or set) used to decode JWT tokens clients provide for authentication. For security the key must be at least 32 characters long. If this parameter is not specified then PostgREST refuses authentication requests. Choosing a value for this parameter beginning with the at sign such as @filename loads the secret out of an external file. This is useful for automating deployments. Note that any binary secrets must be base64 encoded. Both symmetric and asymmetric cryptography are supported. For more info see Asymmetric Keys.

Choosing a value for this parameter beginning with the at sign such as @filename (e.g. @./configs/my-config) loads the secret out of an external file.

Warning

Only when using the Config File, if the jwt-secret contains a $ character by itself it will give errors. In this case, use $$ and PostgREST will interpret it as a single $ character.

jwt-secret-is-base64

Type

Boolean

Default

False

Reloadable

Y

Environment

PGRST_JWT_SECRET_IS_BASE64

In-Database

pgrst.jwt_secret_is_base64

When this is set to true, the value derived from jwt-secret will be treated as a base64 encoded secret.

jwt-cache-max-lifetime

Type

Int

Default

0

Reloadable

Y

Environment

PGRST_JWT_CACHE_MAX_LIFETIME

In-Database

pgrst.jwt_cache_max_lifetime

Maximum number of seconds of lifetime for cached entries. The default 0 disables caching. See JWT Caching.

log-level

Type

String

Default

error

Reloadable

N

Environment

PGRST_LOG_LEVEL

In-Database

n/a

Specifies the level of information to be logged while running PostgREST.

# Only startup and db connection recovery messages are logged
log-level = "crit"

# All the "crit" level events plus server errors (status 5xx) are logged
log-level = "error"

# All the "error" level events plus request errors (status 4xx) are logged
log-level = "warn"

# All the "warn" level events plus all requests (every status code) are logged
log-level = "info"

Because currently there’s no buffering for logging, the levels with minimal logging(crit/error) will increase throughput.

openapi-mode

Type

String

Default

follow-privileges

Reloadable

Y

Environment

PGRST_OPENAPI_MODE

In-Database

pgrst.openapi_mode

Specifies how the OpenAPI output should be displayed.

# Follows the privileges of the JWT role claim (or from db-anon-role if the JWT is not sent)
# Shows information depending on the permissions that the role making the request has
openapi-mode = "follow-privileges"

# Ignores the privileges of the JWT role claim (or from db-anon-role if the JWT is not sent)
# Shows all the exposed information, regardless of the permissions that the role making the request has
openapi-mode = "ignore-privileges"

# Disables the OpenApi output altogether.
# Throws a `404 Not Found` error when accessing the API root path
openapi-mode = "disabled"

openapi-security-active

Type

Boolean

Default

False

Reloadable

Y

Environment

PGRST_OPENAPI_SECURITY_ACTIVE

In-Database

pgrst.openapi_security_active

When this is set to true, security options are included in the OpenAPI output.

openapi-server-proxy-uri

Type

String

Default

n/a

Reloadable

N

Environment

PGRST_OPENAPI_SERVER_PROXY_URI

In-Database

pgrst.openapi_server_proxy_uri

Overrides the base URL used within the OpenAPI self-documentation hosted at the API root path. Use a complete URI syntax scheme:[//[user:password@]host[:port]][/]path[?query][#fragment]. Ex. https://postgrest.com

{
  "swagger": "2.0",
  "info": {
    "version": "0.4.3.0",
    "title": "PostgREST API",
    "description": "This is a dynamic API generated by PostgREST"
  },
  "host": "postgrest.com:443",
  "basePath": "/",
  "schemes": [
    "https"
  ]
}

server-cors-allowed-origins

Type

String

Default

n/a

Reloadable

N

Environment

PGRST_SERVER_CORS_ALLOWED_ORIGINS

In-Database

pgrst.server_cors_allowed_origins

Specifies allowed CORS origins in this config. See CORS.

When this is not set or set to "", PostgREST accepts CORS requests from any domain.

server-host

Type

String

Default

!4

Reloadable

N

Environment

PGRST_SERVER_HOST

In-Database

n/a

Where to bind the PostgREST web server. In addition to the usual address options, PostgREST interprets these reserved addresses with special meanings:

  • * - any IPv4 or IPv6 hostname

  • *4 - any IPv4 or IPv6 hostname, IPv4 preferred

  • !4 - any IPv4 hostname

  • *6 - any IPv4 or IPv6 hostname, IPv6 preferred

  • !6 - any IPv6 hostname

server-port

Type

Int

Default

3000

Reloadable

N

Environment

PGRST_SERVER_PORT

In-Database

n/a

The TCP port to bind the web server. Use 0 to automatically assign a port.

server-trace-header

Type

String

Default

n/a

Reloadable

Y

Environment

PGRST_SERVER_TRACE_HEADER

In-Database

pgrst.server_trace_header

The header name used to trace HTTP requests. See Trace Header.

server-timing-enabled

Type

Boolean

Default

False

Reloadable

Y

Environment

PGRST_SERVER_TIMING_ENABLED

In-Database

pgrst.server_timing_enabled

Enables the Server-Timing header. See Server-Timing Header.

server-unix-socket

Type

String

Default

n/a

Reloadable

N

Environment

PGRST_SERVER_UNIX_SOCKET

In-Database

n/a

Unix domain socket where to bind the PostgREST web server. If specified, this takes precedence over server-port. Example:

server-unix-socket = "/tmp/pgrst.sock"

server-unix-socket-mode

Type

String

Default

660

Reloadable

N

Environment

PGRST_SERVER_UNIX_SOCKET_MODE

In-Database

n/a

Unix file mode to be set for the socket specified in server-unix-socket Needs to be a valid octal between 600 and 777.

server-unix-socket-mode = "660"