Hosted Sinks

Hosted Sinks is currently in beta. The service is under active development and changes may occur. To stay up to date with the latest information, join our Discord Server and follow the #announcements channel.

Hosted Sinks is a managed service on The Graph Market that runs your Substreams sink for you. Instead of provisioning servers, managing deployments, or operating sink processes yourself, you configure a sink in the portal and StreamingFast handles the infrastructure.

A hosted sink continuously reads data from your Substreams package and writes it to your own Postgres or ClickHouse database.

Hosted Sinks is available to organizations on The Graph Market. Your database must be publicly reachable from StreamingFast's infrastructure.

Requirements

Before creating a sink, you need:

• An account on The Graph Market with an active organization.

• A Substreams package (.spkg) that outputs data using a db_out module or relational mappings. See Substreams:SQL for how to build one.

• A running Postgres (default port 5432) or ClickHouse (default port 9000) database that is network-accessible from the internet.

• Your database schema already applied, or a schema that your Substreams package will create automatically. See Sink Config.

Creating a Sink

Navigate to Sinks in the sidebar and click New Sink.

1. Basics

Enter a Sink name. This is a human-readable label for the deployment (e.g., mainnet-erc20-transfers).

2. Substreams Package

Choose how you want to supply the .spkg:

Source	When to use
URL	The package is hosted at a public URL (e.g., GitHub releases, IPFS).
Substreams.dev	The package is published on the Substreams Registry. Enter its ID (e.g., ethereum_common@v0.3.3).

3. Output

Choose Postgres or ClickHouse and fill in the connection details. See walkthroughs provided below for different SQL services you can rely on, with guided setups to run your Hosted Sink.

Postgres fields:

Field	Description
Host	Database hostname or IP address.
Port	Default 5432.
Database	Database name.
Schema	Target schema. Default public.
User	Database user with write access.
Password	Password for the user.
SSL Mode	One of disable, require, verify-ca, or verify-full.

ClickHouse fields:

Field	Description
Host	ClickHouse hostname or IP address.
Port	Default 9000 (native protocol).
Database	Database name. Default default.
User	ClickHouse user.
Password	Password for the user.
Secure (TLS)	Enable TLS for the connection.

Credentials are stored securely and used only to connect the sink process to your database. Use a dedicated database user with write access restricted to the target schema.

4. Execution

Field	Description
Start block	Block number to start processing from. Use 0 to start from genesis.
Stop block	Block number to stop at. Use 0 to follow the chain head indefinitely.
Output module	The name of the Substreams module whose output is written to the database (e.g., db_out).

Advanced options (optional):

Field	Description
Filters	A filter expression passed to the Substreams execution.
Parameters	Module parameters passed at execution time.

5. Deploy

Click Deploy sink. The sink enters the Deploying state while the infrastructure provisions. Once pods are ready it transitions to Deployed and begins indexing.

Provider Walkthroughs

Step-by-step guides for connecting a Hosted Sink to common managed database providers:

Postgres

• Supabase — managed Postgres with a generous free tier.

• Neon — serverless Postgres that scales to zero.

ClickHouse

• ClickHouse Cloud — fully managed ClickHouse from the creators of ClickHouse.

Next Steps

• Monitor and manage your sink — check status, view logs, edit config, stop, or delete.