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SmithDB is an opt-in datastore for self-hosted LangSmith. ClickHouse is required on LangSmith 0.16 and remains the default on 0.17. Do not disable ClickHouse on any version below 0.17. The minimum LangSmith version depends on your cloud. See Cloud support.
SmithDB is a columnar datastore built for agent trace data: deeply nested spans, multi-modal content, and spans that stay open for hours. It keeps durable data in object storage with a per-pod disk cache, and serves LangSmith trace ingestion and queries alongside the existing ClickHouse datastore.

Install SmithDB

Stage infrastructure, deploy SmithDB services, enable dual ingestion, and switch queries after validation.

Prepare supporting infrastructure

Provide a dedicated PostgreSQL metastore, object storage, and cache storage.

Configure for scale

Choose a tested resource tier and size SmithDB workloads.

Configure observability

Scrape SmithDB metrics and export logs and traces to your stack.

Migrate historical data

Backfill ClickHouse history into SmithDB before query cutover.

Metrics reference

Metrics to watch on each SmithDB component and how to read them.

Troubleshoot SmithDB

Gather context, disable SmithDB, or reset a deployment safely.

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Cloud support

You can enable SmithDB on any supported LangSmith Kubernetes installation, whether it is brand new or already serving traffic. Self-host LangSmith on Kubernetes covers the base installation; the guides above cover everything SmithDB adds on top of it. Examples in these guides cover managed Kubernetes on AWS, GCP, and Azure. They do not cover self-managed clusters.

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Components

Enabling SmithDB adds the following workloads to your cluster. Three services cache trace data on disk, on a network-attached volume or local SSD; the other two services are small and run on general compute. The two Jobs run to completion rather than as services. See Cache storage.

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Storage requirements

A self-hosted LangSmith installation uses PostgreSQL for operational data, Redis or Valkey for queuing and caching, and optional blob storage. Traces and feedback live in ClickHouse, in SmithDB, or in both while an installation runs dual ingestion. SmithDB adds its own metastore, object store, and cache storage. On 0.17, a new installation can run SmithDB without ClickHouse; see Install without ClickHouse. Retiring ClickHouse from an existing installation is a separate procedure; contact LangChain through the Support Portal before considering it. For SDK method changes that work with both ClickHouse and SmithDB, see Migrate to SmithDB-backed SDK methods.
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