Composite storage

MastraCompositeStore can compose storage domains from different providers. Use it when you need different databases for different purposes. For example, use LibSQL for memory and PostgreSQL for workflows.

Installation

MastraCompositeStore is included in @mastra/core:

npm

npm install @mastra/core@latest

pnpm

pnpm add @mastra/core@latest

Yarn

yarn add @mastra/core@latest

Bun

bun add @mastra/core@latest

You'll also need to install the storage providers you want to compose:

npm

npm install @mastra/pg@latest @mastra/libsql@latest @mastra/mongodb@latest

pnpm

pnpm add @mastra/pg@latest @mastra/libsql@latest @mastra/mongodb@latest

Yarn

yarn add @mastra/pg@latest @mastra/libsql@latest @mastra/mongodb@latest

Bun

bun add @mastra/pg@latest @mastra/libsql@latest @mastra/mongodb@latest

Storage domains

Mastra organizes storage into domains, each handling a specific type of data. Each domain can be backed by a different storage adapter, and domain classes are exported from each storage package.

Domain	Description
memory	Conversation persistence for agents. Stores threads (conversation sessions), messages, resources (user identities), and working memory (persistent context across conversations).
workflows	Workflow execution state. When workflows suspend for human input, external events, or scheduled resumption, their state is persisted here to enable resumption after server restarts.
scores	Evaluation results from Mastra's evals system. Scores and metrics are persisted here for analysis and comparison over time.
observability	Telemetry data including traces and spans. Agent interactions, tool calls, and LLM requests generate spans collected into traces for debugging and performance analysis.
agents	Agent configurations for stored agents. Enables agents to be defined and updated at runtime without code deployments.
datasets	Evaluation datasets used for experiment runs. Stores dataset definitions, schemas, and versioned items.
experiments	Experiment runs and per-item experiment results linked to datasets and targets.

备注

MastraCompositeStore accepts all of the domain keys above, but storage adapter support varies by package. You can mix adapters per domain, but only for domains implemented and exported by those adapters. For example, memory: new MemoryLibSQL(...) and workflows: new WorkflowsPG(...) is valid because both packages export those domain classes.

Usage

Basic composition

Import domain classes directly from each store package and compose them:

src/mastra/index.ts

import { MastraCompositeStore } from '@mastra/core/storage'
import { WorkflowsPG, ScoresPG } from '@mastra/pg'
import { MemoryLibSQL } from '@mastra/libsql'
import { Mastra } from '@mastra/core'

export const mastra = new Mastra({
  storage: new MastraCompositeStore({
    id: 'composite',
    domains: {
      memory: new MemoryLibSQL({ url: 'file:./local.db' }),
      workflows: new WorkflowsPG({ connectionString: process.env.DATABASE_URL }),
      scores: new ScoresPG({ connectionString: process.env.DATABASE_URL }),
    },
  }),
})

With a default storage

Use default to specify a fallback storage, then override specific domains:

src/mastra/index.ts

import { MastraCompositeStore } from '@mastra/core/storage'
import { PostgresStore } from '@mastra/pg'
import { MemoryLibSQL } from '@mastra/libsql'
import { Mastra } from '@mastra/core'

const pgStore = new PostgresStore({
  id: 'pg',
  connectionString: process.env.DATABASE_URL,
})

export const mastra = new Mastra({
  storage: new MastraCompositeStore({
    id: 'composite',
    default: pgStore,
    domains: {
      memory: new MemoryLibSQL({ url: 'file:./local.db' }),
    },
  }),
})

Mixed backends

Use domain classes from each storage package to route different domains to different backends. The following example stores memory and workflow state in MongoDB, then routes observability to ClickHouse:

src/mastra/index.ts

import { Mastra } from '@mastra/core'
import { MastraCompositeStore } from '@mastra/core/storage'
import { ObservabilityStorageClickhouse } from '@mastra/clickhouse'
import { MemoryStorageMongoDB, WorkflowsStorageMongoDB } from '@mastra/mongodb'

export const mastra = new Mastra({
  storage: new MastraCompositeStore({
    id: 'composite',
    domains: {
      memory: new MemoryStorageMongoDB({
        uri: process.env.MONGODB_URI,
        dbName: 'mastra_memory',
      }),
      workflows: new WorkflowsStorageMongoDB({
        uri: process.env.MONGODB_URI,
        dbName: 'mastra_workflows',
      }),
      observability: new ObservabilityStorageClickhouse({
        url: process.env.CLICKHOUSE_URL,
        username: process.env.CLICKHOUSE_USERNAME,
        password: process.env.CLICKHOUSE_PASSWORD,
      }),
    },
  }),
})

Disabling a domain

Set a domain to false to disable it. A disabled domain doesn't fall back to default, so data for that domain isn't persisted:

src/mastra/index.ts

import { MastraCompositeStore } from '@mastra/core/storage'
import { PostgresStore } from '@mastra/pg'
import { Mastra } from '@mastra/core'

const pgStore = new PostgresStore({
  id: 'pg',
  connectionString: process.env.DATABASE_URL,
})

export const mastra = new Mastra({
  storage: new MastraCompositeStore({
    id: 'composite',
    default: pgStore,
    domains: {
      // don't persist traces and spans
      observability: false,
    },
  }),
})

Options

id:

string

Unique identifier for this storage instance.

default?:

MastraCompositeStore

Default storage adapter. Domains not explicitly specified in domains will use this storage's domains as fallbacks.

editor?:

MastraCompositeStore

Storage adapter for Editor-owned domains, including agents, prompt blocks, scorers, MCP clients and servers, workspaces, and skills. Takes precedence over default storage but not explicit domain overrides.

disableInit?:

boolean

When true, automatic initialization is disabled. You must call init() explicitly.

domains?:

object

Individual domain overrides. Each domain can come from a different storage adapter. These take precedence over both editor and default storage. Set a domain to false to disable it entirely; a disabled domain does not fall back to editor or default.

object

memory?:

MemoryStorage

Storage for threads, messages, and resources.

workflows?:

WorkflowsStorage

Storage for workflow snapshots.

scores?:

ScoresStorage

Storage for evaluation scores.

observability?:

ObservabilityStorage

Storage for traces and spans.

agents?:

AgentsStorage

Storage for stored agent configurations.

datasets?:

DatasetsStorage

Storage for dataset metadata, dataset items, and dataset versions.

experiments?:

ExperimentsStorage

Storage for experiment runs and per-item experiment results.

workflowDefinitions?:

WorkflowDefinitionsStorage

Storage for persisted workflow definitions.

promptBlocks?:

PromptBlocksStorage

Storage for stored prompt blocks and their versions.

scorerDefinitions?:

ScorerDefinitionsStorage

Storage for stored scorer definitions and their versions.

mcpClients?:

MCPClientsStorage

Storage for stored MCP client configurations and their versions.

mcpServers?:

MCPServersStorage

Storage for stored MCP server configurations and their versions.

workspaces?:

WorkspacesStorage

Storage for stored workspace configurations and their versions.

skills?:

SkillsStorage

Storage for stored skill definitions and their versions.

favorites?:

FavoritesStorage

Storage for user favorites on stored entities.

blobs?:

BlobStore

Content-addressable storage for file contents used by skill versioning.

backgroundTasks?:

BackgroundTasksStorage

Storage for background task state.

schedules?:

SchedulesStorage

Storage for schedules that the scheduler fires.

channels?:

ChannelsStorage

Storage for channel installations and configuration.

harness?:

HarnessStorage

Storage for harness sessions.

toolProviderConnections?:

ToolProviderConnectionsStorage

Storage for authorized tool provider connections.

notifications?:

NotificationsStorage

Storage for notifications and their delivery state.

threadState?:

ThreadStateStorage

Storage for per-thread agent state, such as task lists and goals.

knowledge?:

KnowledgeStorage

Storage for knowledge nodes and records. Experimental.

Initialization

MastraCompositeStore initializes each configured domain independently. When passed to the Mastra class, init() is called automatically:

src/mastra/index.ts

import { MastraCompositeStore } from '@mastra/core/storage'
import { MemoryPG, WorkflowsPG, ScoresPG } from '@mastra/pg'
import { Mastra } from '@mastra/core'

const storage = new MastraCompositeStore({
  id: 'composite',
  domains: {
    memory: new MemoryPG({ connectionString: process.env.DATABASE_URL }),
    workflows: new WorkflowsPG({ connectionString: process.env.DATABASE_URL }),
    scores: new ScoresPG({ connectionString: process.env.DATABASE_URL }),
  },
})

export const mastra = new Mastra({
  storage, // init() called automatically
})

If using storage directly, call init() explicitly:

import { MastraCompositeStore } from '@mastra/core/storage'
import { MemoryPG } from '@mastra/pg'

const storage = new MastraCompositeStore({
  id: 'composite',
  domains: {
    memory: new MemoryPG({ connectionString: process.env.DATABASE_URL }),
  },
})

await storage.init()

// Access domain-specific stores via getStore()
const memoryStore = await storage.getStore('memory')
const thread = await memoryStore?.getThreadById({ threadId: '...' })

Closing connections

close() releases connections for the stores used by a composite, including the default and editor stores and any domain with its own client. Each store closes once even if it backs several domains. When the composite is passed to the Mastra class, shutdown() calls close():

src/mastra/index.ts

import { MastraCompositeStore } from '@mastra/core/storage'
import { PostgresStore } from '@mastra/pg'
import { Mastra } from '@mastra/core'

const pgStore = new PostgresStore({
  id: 'pg-storage',
  connectionString: process.env.DATABASE_URL,
})

export const mastra = new Mastra({
  storage: new MastraCompositeStore({ id: 'composite', default: pgStore }),
})

process.on('SIGTERM', async () => {
  // Releases the Postgres pool, so the process can exit
  await mastra.shutdown()
})

A store you construct only to supply a domain isn't reachable through the composite. Keep a reference to it and close it yourself:

src/mastra/index.ts

import { MastraCompositeStore } from '@mastra/core/storage'
import { ClickhouseStore } from '@mastra/clickhouse'
import { PostgresStore } from '@mastra/pg'
import { Mastra } from '@mastra/core'

const pgStore = new PostgresStore({
  id: 'pg-storage',
  connectionString: process.env.DATABASE_URL,
})

const clickhouseStore = new ClickhouseStore({
  id: 'clickhouse-storage',
  url: process.env.CLICKHOUSE_URL,
  username: process.env.CLICKHOUSE_USERNAME,
  password: process.env.CLICKHOUSE_PASSWORD,
})

export const mastra = new Mastra({
  storage: new MastraCompositeStore({
    id: 'composite',
    default: pgStore,
    domains: { observability: clickhouseStore.stores?.observability },
  }),
})

process.on('SIGTERM', async () => {
  await mastra.shutdown()
  await clickhouseStore.close()
})

Use cases

Separate databases for different workloads

Use a local database for development while keeping production data in a managed service:

import { MastraCompositeStore } from '@mastra/core/storage'
import { MemoryPG, WorkflowsPG, ScoresPG } from '@mastra/pg'
import { MemoryLibSQL } from '@mastra/libsql'

const storage = new MastraCompositeStore({
  id: 'composite',
  domains: {
    // Use local SQLite for development, PostgreSQL for production
    memory:
      process.env.NODE_ENV === 'development'
        ? new MemoryLibSQL({ url: 'file:./dev.db' })
        : new MemoryPG({ connectionString: process.env.DATABASE_URL }),
    workflows: new WorkflowsPG({ connectionString: process.env.DATABASE_URL }),
    scores: new ScoresPG({ connectionString: process.env.DATABASE_URL }),
  },
})

Specialized storage for observability

Observability data can quickly overwhelm general-purpose databases in production. A single agent interaction can generate hundreds of spans, and high-traffic applications can produce thousands of traces per day.

ClickHouse is recommended for production observability because it's optimized for high-volume, write-heavy analytics workloads. Use composite storage to route observability to ClickHouse while keeping other data in your primary database:

import { MastraCompositeStore } from '@mastra/core/storage'
import { MemoryPG, WorkflowsPG, ScoresPG } from '@mastra/pg'
import { ObservabilityStorageClickhouseVNext } from '@mastra/clickhouse'

const storage = new MastraCompositeStore({
  id: 'composite',
  domains: {
    memory: new MemoryPG({ connectionString: process.env.DATABASE_URL }),
    workflows: new WorkflowsPG({ connectionString: process.env.DATABASE_URL }),
    scores: new ScoresPG({ connectionString: process.env.DATABASE_URL }),
    observability: new ObservabilityStorageClickhouseVNext({
      url: process.env.CLICKHOUSE_URL,
      username: process.env.CLICKHOUSE_USERNAME,
      password: process.env.CLICKHOUSE_PASSWORD,
    }),
  },
})

备注

ObservabilityStorageClickhouseVNext is the current observability domain implementation. The legacy ObservabilityStorageClickhouse class is also exported and remains supported for projects that haven't migrated. See the ClickHouse storage reference for details.

Replicated ClickHouse for multi-replica clusters

For self-managed ClickHouse clusters with multiple replicas, set replication so Mastra emits ReplicatedMergeTree engines and applies ON CLUSTER to its DDL:

import { MastraCompositeStore } from '@mastra/core/storage'
import { MemoryPG, WorkflowsPG, ScoresPG } from '@mastra/pg'
import { ObservabilityStorageClickhouseVNext } from '@mastra/clickhouse'

const storage = new MastraCompositeStore({
  id: 'composite',
  domains: {
    memory: new MemoryPG({ connectionString: process.env.DATABASE_URL }),
    workflows: new WorkflowsPG({ connectionString: process.env.DATABASE_URL }),
    scores: new ScoresPG({ connectionString: process.env.DATABASE_URL }),
    observability: new ObservabilityStorageClickhouseVNext({
      url: process.env.CLICKHOUSE_URL,
      username: process.env.CLICKHOUSE_USERNAME,
      password: process.env.CLICKHOUSE_PASSWORD,
      replication: {
        cluster: 'production_cluster',
        // Optional (defaults shown):
        // zookeeperPath: '/clickhouse/tables/{shard}/{database}/{table}',
        // replicaName: '{replica}',
      },
    }),
  },
})

Don't set replication on ClickHouse Cloud. Cloud rewrites MergeTree to SharedMergeTree server-side. See the ClickHouse storage reference for the full config shape and operator notes.

备注

This approach is also required when using storage providers that don't support observability (like Convex, DynamoDB, or Cloudflare). See the MastraStorageExporter documentation for the full list of supported providers.