Configuration
You can configure the DBOS Transact runtime with a configuration file. Valid configuration files must be:
- Named
dbos-config.yaml
- Located at the application package root.
- Valid YAML conforming to the schema described below.
You can use environment variables for configuration values through the syntax key: ${VALUE}
. They are expanded during npx dbos start
or dbos-cloud app deploy
and passed to the app securely. We strongly recommend using environment variables for secrets like the database password, as demonstrated below.
Fields
Each dbos-config.yaml
file has the following fields and sections:
- language: The application language field. Must be set to
node
for TypeScript applications. - database: The database section.
- runtimeConfig: The runtime section.
- http: The HTTP section.
- application: The application configuration section.
- env: The environment variables section.
- telemetry: The telemetry section.
Database
The database section is used to set up the connection to the database. DBOS currently only supports Postgres-compatible databases. Every field is required unless otherwise specified.
- hostname: Database server hostname. For local deployment only, not used in DBOS Cloud.
- port: Database server port. For local deployment only, not used in DBOS Cloud.
- username: Username with which to connect to the database server. For local deployment only, not used in DBOS Cloud.
- password: Password with which to connect to the database server. We recommend using an environment variable for this field, instead of plain text. For local deployment only, not used in DBOS Cloud.
- app_db_name: (optional): Name of the application database. If not supplied, the application name (with dashes replaced with underscores for compatibility) is used instead.
- sys_db_name (optional): Name of the system database in which DBOS stores internal state. Defaults to
{app_db_name}_dbos_sys
. For local deployment only, not used in DBOS Cloud. - app_db_client (optional): Client to use for connecting to the application database. Must be one of
knex
,drizzle
,typeorm
, orprisma
. Defaults toknex
. The client specified here is the one used inTransactionContext
. - ssl_ca (optional): If using SSL/TLS to securely connect to a database, path to an SSL root certificate file. Equivalent to the
sslrootcert
connection parameter inpsql
. - connectionTimeoutMillis (optional): Database connection timeout in milliseconds. Defaults to
3000
. - local_suffix (optional): Whether to suffix
app_db_name
with '_local'. Set to true when doing local development using a DBOS Cloud database. For local development only, not used in DBOS Cloud. - migrate (optional): A list of commands to run to apply your application's schema to the database. We recommend using a Typescript-based migration tool like Knex, Drizzle, TypeORM, or Prisma.
- rollback (optional) A list of commands to run to roll back the last batch of schema migrations.
Example:
database:
hostname: 'localhost'
port: 5432
username: 'postgres'
password: ${PGPASSWORD}
app_db_client: 'knex'
migrate: ['npx knex migrate:latest']
rollback: ['npx knex migrate:rollback']
Runtime
This section is used to specify DBOS runtime parameters.
- port (optional): The port from which to serve your functions. Defaults to
3000
. Usingnpx dbos start -p <port>
overrides this config parameter. - entrypoints (optional): The compiled Javascript files where DBOS looks for your application's code. At startup, the DBOS runtime automatically loads all classes exported from these files, serving their endpoints and registering their decorated functions. Defaults to
[dist/operations.js]
.
Example:
runtimeConfig:
port: 3000 # (default)
entrypoints:
- 'dist/operations.js' # (default)
HTTP
This section is used to specify DBOS HTTP parameters.
- cors_middleware (optional): Whether to allow cross-origin requests (via CORS middleware). Default is
true
. - credentials (optional): If
cors_middleware
is enabled, whether to allow cross-origin requests that include credentials. Default istrue
. - allowed_origins (optional): If
cors_middleware
is enabled, a list of origins/domains that are permitted to make cross-origin requests. Default is to allow any origin.
Example:
http:
cors_middleware: true
credentials: true
allowed_origins:
- 'https://partner.com'
- 'https://app.internal.com'
Application
Applications can optionally use the application configuration to define custom properties as key-value pairs.
These properties can be retrieved from any context via the getConfig
method.
Example:
application:
PAYMENTS_SERVICE: 'https://stripe.com/payment'
Environment Variables
Applications can optionally use the env
configuration to define environment variables.
These are set in your application before its code is initialized and can be retrieved from process.env
like any other environment variables.
For example, the WEB_PORTAL
variable set below could be retrieved from an application as process.env.WEB_PORTAL
.
Environment variables configured here are automatically exported to and set in DBOS Cloud.
Example:
env:
WEB_PORTAL: 'https://example.com'
Telemetry
You can use the configuration file to tune the behavior of DBOS logging facility. Note all options in this section are optional and will, if not specified, use the default values indicated in the example below.
Logs
- logLevel: Filters, by severity, what logs should be printed. Defaults to
'info'
. Usingnpx dbos start -l <logLevel>
overrides this config parameter. - addContextMetadata: Enables the addition of contextual information, such as workflow identity UUID, to each log entry. Defaults to
true
. - silent: Silences the logger. Defaults to
false
.
Example:
telemetry:
logs:
logLevel: 'info' # info (default) | debug | warn | emerg | alert | crit | error
addContextMetadata: true # true (default) | false
silent: false # false (default) | true
OTLPExporter
Configures the Transact OpenTelemetry exporter.
- logsEndpoint: The endpoint to which logs are sent.
- tracesEndpoint: The endpoint to which traces are sent.
The Transact exporter uses protobuf over HTTP. An example configuration for a local Jaeger instance with default configuration is shown below.
Example:
telemetry:
OTLPExporter:
logsEndpoint: 'http://localhost:4318/v1/logs'
tracesEndpoint: 'http://localhost:4318/v1/traces'
Configuration Schema File
There is a schema file available for the DBOS configuration file schema in our GitHub repo. This schema file can be used to provide an improved YAML editing experience for developer tools that leverage it. For example, the Visual Studio Code RedHat YAML extension provides tooltips, statement completion and real-time validation for editing DBOS config files. This extension provides multiple ways to associate a YAML file with its schema. The easiest is to simply add a comment with a link to the schema at the top of the config file:
# yaml-language-server: $schema=https://raw.githubusercontent.com/dbos-inc/dbos-ts/main/dbos-config.schema.json