Litestream

Configuration File

The YAML configuration file provides a way to list databases and replicas that Litestream should manage. In addition, there are global variables that can be applied to all replicas.

The default path for the configuration file is /etc/litestream.yml.

Variable expansion

By default, Litestream will perform environment variable expansion within the config file before reading it. Any references to $VAR or ${VAR} formatted variables will be replaced with their environment variable values. If no value is set then it will be replaced with an empty string.

This can cause issues if you have a value in a configuration file which has a dollar sign followed by characters—for example, a password. In this case, you can set the -no-expand-env flag on any litestream command to disable expansion.

Global settings

AWS credentials

If you are using AWS S3 replication, it can be useful to specify your credentials in one place instead of for each replica:

access-key-id:     AKIAxxxxxxxxxxxxxxxx
secret-access-key: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/xxxxxxxxx

Metrics

Litestream produces a continuous stream of metrics that are exported as a Prometheus endpoint. These are disabled by default as it requires an HTTP server to start. You can enable it by setting a bind address in the config:

addr: ":9090"

When you start Litestream with this setting enabled, you’ll see metrics at http://localhost:9090/metrics

MCP (Model Context Protocol)

v0.5.0 Litestream includes built-in support for the Model Context Protocol (MCP), allowing AI assistants to interact with your databases and replicas. Enable the MCP server by setting a bind address:

mcp-addr: ":3001"

When enabled, the MCP server will start alongside replication and provide AI tools at http://localhost:3001. See the MCP command reference for available tools and usage.

Logging

v0.3.12 Log type can be set to either “text” or “json”. Logging level can be set to “debug”, “info”, “warn” or “error”. By setting stderr to true logs will be written to stderr instead of stdout.

The defaults are shown below:

logging:
  level: info
  type: text
  stderr: false

Database settings

Litestream can monitor one or more database files that are specified in the configuration file. Database files are also referenced in litestream commands by their absolute path.

Each database configuration includes the database path and replica configuration. v0.5.0 Database configuration has been simplified to use a single replica field instead of the deprecated replicas array.

dbs:
  - path: /var/lib/db1
    replica:
      url: s3://mybkt.litestream.io/db1

  - path: /var/lib/db2
    replica:
      url: nats://nats.example.com:4222/my-bucket
      username: litestream
      password: ${NATS_PASSWORD}

Database configuration options

Each database supports the following configuration options:

  • path—Absolute path to the SQLite database file
  • meta-path—Path to store Litestream metadata (defaults to <path>-litestream)
  • monitor-interval—How often to check for changes (default: 1s)
  • checkpoint-interval—How often to perform WAL checkpoints (default: 1m)
  • busy-timeout—SQLite busy timeout (default: 1s)
  • min-checkpoint-page-count—Minimum pages before checkpointing (default: 1000)
  • max-checkpoint-page-count—Maximum pages before forcing checkpoint (default: 10000)
  • replica—Single replica configuration (replaces deprecated replicas array)

Example with database-level options:

dbs:
  - path: /var/lib/myapp.db
    meta-path: /var/lib/myapp-litestream
    monitor-interval: 500ms
    checkpoint-interval: 30s
    busy-timeout: 5s
    min-checkpoint-page-count: 500
    max-checkpoint-page-count: 5000
    replica:
      url: s3://mybucket/myapp
      sync-interval: 1s

Replica settings

Litestream supports six types of replicas:

  • "abs" replicates a database to an Azure Blob Storage container.
  • "file" replicates a database to another local file path.
  • "gs" replicates a database to a Google Cloud Storage bucket.
  • "nats" replicates a database to a NATS JetStream Object Store.
  • "s3" replicates a database to an S3-compatible bucket.
  • "sftp" replicates a database to a remote server via SFTP.

All replicas have unique name which is specified by the "name" field. If a name is not specified then the name defaults to the replica type. The name is only needed when using multiple replicas of the same type on a database.

The following replica settings are also available for all replica types:

  • url—Short-hand form of specifying a replica location. Setting this field will apply changes to multiples fields including bucket, path, region, etc.

  • retention—The amount of time that snapshot & LTX files will be kept. After the retention period, a new snapshot will be created and the old one will be removed. LTX files that exist before the oldest snapshot will also be removed. Defaults to 24h.

  • retention-check-interval—Specifies how often Litestream will check if retention needs to be enforced. Defaults to 1h.

  • snapshot-interval—Specifies how often new snapshots will be created. This is used to reduce the time to restore since newer snapshots will have fewer LTX frames to apply. Retention still applies to these snapshots.

    If you do not set a snapshot interval then a new snapshot will be created whenever retention is performed. Retention occurs every 24 hours by default.

  • validation-interval—When specified, Litestream will automatically restore and validate that the data on the replica matches the local copy. Disabled by default. Enabling this will significantly increase the cost of running Litestream as S3 services charge for downloads.

  • sync-interval—Frequency in which frames are pushed to the replica. Defaults to 1s. Decreasing this value (increasing sync frequency) can significantly increase cloud storage costs due to more frequent PUT requests. See the Cost Considerations section below for details.

  • age—Client-side encryption with age, see Encryption for configuration details. Defaults to off.

S3 replica

The easiest way to configure an S3 replica is to use the url field:

dbs:
  - path: /var/lib/db
    replicas:
      - url: s3://mybkt.litestream.io/db

However, you can break this out into separate fields as well:

dbs:
  - path: /var/lib/db
    replicas:
      - type:   s3
        bucket: mybkt.litestream.io
        path:   db

In addition, you can specify the region and AWS credentials per-replica:

dbs:
  - path: /var/lib/db
    replicas:
      - url: s3://mybkt.litestream.io/db
        region: us-east-1
        access-key-id: AKIAxxxxxxxxxxxxxxxx
        secret-access-key: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/xxxxxxxxx

The following settings are specific to S3 replicas:

  • access-key-id—Replica-specific authentication key. If not specified, the global key or the LITESTREAM_ACCESS_KEY_ID environment variable will be used instead. The AWS_ACCESS_KEY_ID variable can also be used.

  • secret-access-key—Replica-specific secret key. If not specified, the global secret or the LITESTREAM_SECRET_ACCESS_KEY environment variable will be used instead. The AWS_SECRET_ACCESS_KEY variable can also be used.

  • bucket—Specifies the name of the remote bucket to replicate to.

  • path—Specifies the path to use within the bucket.

  • region—Specifies the bucket’s region. Only used for AWS S3 & Backblaze B2.

  • endpoint—Specifies the endpoint URL of the S3-compatible service. Only required for non-AWS services.

  • force-path-style—Uses the path style which is required by non-AWS services. This is automatically enabled if endpoint is set.

  • skip-verify—Disables TLS verification. This is useful when testing against a local node such as MinIO and you are using self-signed certificates.

File replica

File replicas can be configured using the "path" field:

dbs:
  - path: /var/lib/db
    replicas:
      - path: /backup/db

If no "type" field is specified and a "url" is not used then "file" is assumed.

Google Cloud Storage (GCS) replica

GCS replicas can be configured using the url field:

dbs:
  - path: /var/lib/db
    replica:
      url: gs://mybucket.example.com/db

Or by specifying individual fields:

dbs:
  - path: /var/lib/db
    replica:
      type: gs
      bucket: mybucket.example.com
      path: db

GCS authentication uses Google Application Default Credentials (ADC). Set the GOOGLE_APPLICATION_CREDENTIALS environment variable to point to your service account key file, or use workload identity in GKE environments.

Azure Blob Storage (ABS) replica

v0.5.0 Updated to use Azure SDK v2.

ABS replicas can be configured using the url field:

dbs:
  - path: /var/lib/db
    replica:
      url: abs://account@myaccount.blob.core.windows.net/container/db

Or by specifying individual fields:

dbs:
  - path: /var/lib/db
    replica:
      type: abs
      account-name: myaccount
      account-key: ${AZURE_ACCOUNT_KEY}
      bucket: container
      path: db
      endpoint: https://myaccount.blob.core.windows.net/

The following settings are specific to ABS replicas:

  • account-name—Azure storage account name
  • account-key—Azure storage account key or use AZURE_STORAGE_KEY environment variable
  • bucket—Container name within the storage account
  • path—Path within the container
  • endpoint—Custom endpoint URL (optional)

SFTP replica

SFTP replicas allow replication to remote servers via SSH File Transfer Protocol:

dbs:
  - path: /var/lib/db
    replica:
      url: sftp://user:password@example.com:22/backup/db

Or with individual fields:

dbs:
  - path: /var/lib/db
    replica:
      type: sftp
      host: example.com:22
      user: backup-user
      password: ${SFTP_PASSWORD}
      key-path: /etc/litestream/sftp_key
      path: /backup/db

The following settings are specific to SFTP replicas:

  • host—SFTP server hostname and port
  • user—Username for authentication
  • password—Password for authentication (not recommended for production)
  • key-path—Path to SSH private key file for key-based authentication
  • path—Remote path where replica files will be stored

NATS JetStream Object Store replica

v0.5.0 NATS JetStream Object Store provides distributed storage.

NATS replicas can be configured using the url field:

dbs:
  - path: /var/lib/db
    replica:
      url: nats://nats.example.com:4222/my-bucket
      username: litestream
      password: ${NATS_PASSWORD}

Or with individual fields:

dbs:
  - path: /var/lib/db
    replica:
      type: nats
      bucket: my-bucket
      username: litestream
      password: ${NATS_PASSWORD}
      
      # TLS configuration
      tls: true
      root-cas:
        - /etc/ssl/certs/nats-ca.crt
      client-cert: /etc/ssl/certs/nats-client.crt
      client-key: /etc/ssl/private/nats-client.key
      
      # Connection tuning
      max-reconnects: -1
      reconnect-wait: 2s
      timeout: 10s

The following settings are specific to NATS replicas:

Connection Settings:

  • bucket—NATS JetStream Object Store bucket name (must be pre-created)
  • max-reconnects—Maximum reconnection attempts (-1 for unlimited)
  • reconnect-wait—Wait time between reconnection attempts
  • timeout—Connection timeout

Authentication Options (choose one):

  • username & password—Basic username/password authentication
  • jwt & seed—JWT token and seed for NATS 2.0 authentication
  • creds—Path to NATS credentials file
  • nkey—NKey for signature-based authentication
  • token—Simple token authentication

TLS Options:

  • tls—Enable TLS encryption
  • root-cas—List of CA certificate file paths
  • client-cert—Client certificate for mutual TLS
  • client-key—Client private key for mutual TLS

See the NATS Integration Guide for detailed setup instructions.

Legacy Multiple Replicas

Previous versions supported multiple replicas per database using the replicas array. This has been simplified to use a single replica field:

Deprecated (v0.3.x and earlier):

dbs:
  - path: /local/path/to/db
    replicas:
      - name: my_aws_replica
        url: s3://myawsbucket/db
      - name: my_do_replica
        url: s3://mybkt.nyc3.digitaloceanspaces.com/db

Current (v0.5.0+):

dbs:
  - path: /local/path/to/db
    replica:
      url: s3://myawsbucket/db

If you need multiple backup destinations, consider using your cloud provider’s cross-region replication features or multiple Litestream instances.

Retention period

Replicas maintain a snapshot of the database as well as a contiguous sequence of SQLite WAL page updates. These updates take up space so new snapshots are created and old WAL files are dropped through a process called “retention”.

The default retention period is 24h. You can change that with the retention field. Retention is enforced periodically and defaults to every 1h. This can be changed with the retention-check-interval field.

dbs:
  - path: /var/lib/db
    replicas:
      - url: s3://mybkt.litestream.io/db
        retention: 4h

Duration values can be specified using second (s), minute (m), or hour (h) but days, weeks, & years are not supported.

Validation interval

Because Litestream performs physical replication, the resulting database files restored from replicas will match byte-for-byte. Litestream has an option to periodically validate replicas by restoring them and comparing their checksum to the primary database’s checksum.

Please note that frequently restoring from S3 can be expensive.

It can be enabled by setting the validation-interval field:

dbs:
  - path: /var/lib/db
    replicas:
      - url: s3://mybkt.litestream.io/db
        validation-interval: 6h

Encryption

v0.3.10 Client-side encryption can be enabled per replica by adding an age section to the replica configuration with corresponding identities and recipients fields.

dbs:
  - path: /var/lib/db
    replica:
      url: s3://mybkt.litestream.io/db
      age:
        identities:
          - AGE-SECRET-KEY-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
        recipients:
          - age1xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

To generate keys, refer to the age README how to install and use the command line tools.

As of now identities must be a superset of recipients but key rotation can be achieved by adding a new identity while changing the recipient list to only have a key for it.

Note that enabling encryption after replication has already been done can confuse Litestream so it is recommended the replica is empty when doing so. Restoring from a replica that has mixed encrypted and non-encrypted files will fail.

Identity Files

v0.5.0 You can also reference identity files instead of embedding keys directly:

dbs:
  - path: /var/lib/db
    replica:
      url: s3://mybkt.litestream.io/db
      age:
        identities:
          - /etc/litestream/age-identity.txt
        recipients:
          - age1xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Cost Considerations

Understanding the cost implications of Litestream configuration is important for managing cloud storage expenses. The primary cost drivers vary by configuration:

Sync Interval Costs

The sync-interval setting primarily affects PUT request costs, not storage costs. Litestream only uploads frames when the database changes, but frequent intervals mean more frequent requests when changes occur.

PUT Request Cost Examples (AWS S3 pricing: $0.000005 per request):

  • sync-interval: 1s with constant writes: ~2,592,000 requests/month = $12.96/month
  • sync-interval: 10s with constant writes: ~259,200 requests/month = $1.30/month
  • sync-interval: 1m with constant writes: ~43,200 requests/month = $0.22/month

Note: Actual costs depend on your database write patterns. Litestream batches writes by time interval, so costs scale with write frequency.

Storage vs Request Costs

Request Costs (Primary Driver):

  • PUT operations for uploading frames and snapshots
  • GET operations for restores and validation
  • LIST operations for cleanup and maintenance

Storage Costs (Usually Minimal):

  • LTX files (containing SQLite page updates and metadata)
  • Snapshot files (full database copies)
  • Typically much lower than request costs for active databases

Transfer Costs:

  • Ingress: Often free (AWS S3, Google Cloud)
  • Egress: Charged for restores and validation
  • Varies significantly by cloud provider

Retention Impact

The retention setting affects storage costs by controlling:

  • How long LTX frames are kept (affects storage volume)
  • When new snapshots are created (affects PUT requests)
  • Storage cleanup frequency (affects LIST requests)

Shorter retention periods reduce storage costs but may increase snapshot creation frequency. Longer retention periods increase storage but reduce snapshot overhead.

Provider-Specific Considerations

Different S3-compatible providers have varying pricing models:

  • AWS S3: Charges for PUT requests, ingress typically free
  • Backblaze B2: Lower storage costs, different request pricing
  • DigitalOcean Spaces: Includes egress allowance
  • MinIO/Self-hosted: Only infrastructure costs

Always consult your provider’s current pricing documentation for accurate estimates.

Complete Configuration Example

Example showing available configuration options:

# Global settings
access-key-id: ${AWS_ACCESS_KEY_ID}
secret-access-key: ${AWS_SECRET_ACCESS_KEY}

# Metrics endpoint
addr: ":9090"

# MCP server for AI integration  
mcp-addr: ":3001"

# Subcommand to execute
exec: "myapp -config /etc/myapp.conf"

# Logging configuration
logging:
  level: info
  type: text
  stderr: false

# Compaction levels
levels:
  - interval: 5m
  - interval: 1h
  - interval: 24h

# Global snapshot settings
snapshot:
  interval: 1h
  retention: 24h

# Database configurations
dbs:
  # S3 replica with encryption
  - path: /var/lib/app1.db
    monitor-interval: 1s
    checkpoint-interval: 1m
    replica:
      url: s3://mybucket/app1
      region: us-east-1
      sync-interval: 1s
      retention: 72h
      age:
        identities:
          - /etc/litestream/age-identity.txt
        recipients:
          - age1xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  
  # NATS replica with TLS
  - path: /var/lib/app2.db
    replica:
      type: nats
      url: nats://nats.example.com:4222/app2-bucket
      username: litestream
      password: ${NATS_PASSWORD}
      tls: true
      root-cas:
        - /etc/ssl/certs/nats-ca.crt
      max-reconnects: -1
      reconnect-wait: 2s
      
  # File replica for local backup
  - path: /var/lib/app3.db
    replica:
      path: /backup/app3
      retention: 168h  # 1 week

Migration from v0.3.x

If you’re upgrading from Litestream v0.3.x, note these breaking changes:

  1. Multiple replicas deprecated: Use single replica field instead of replicas array
  2. LTX terminology: References to “WAL” are now “LTX” (Litestream Transaction Log)
  3. Updated cloud clients: AWS SDK v2, Azure SDK v2 with potential authentication changes
  4. New replica types: NATS and SFTP support added
  5. MCP integration: New AI assistant capabilities

See the Migration Guide for detailed upgrade instructions.

Command: databases →