memory changedmanaged-agents/memory

The first capture of this source. The page was already there, and this is what it said.

---
title: Using agent memory
url: https://platform.claude.com/docs/en/managed-agents/memory
description: Give your agents persistent memory that survives across sessions using memory stores.
---

Each Managed Agents session starts with a fresh context by default. When a session ends, any state the agent built up is gone. Memory stores let the agent carry information across sessions: user preferences, project conventions, prior mistakes, and domain context.

<Note>
  Managed Agents API requests require the `managed-agents-2026-04-01` beta header, except memory store endpoints, which use `agent-memory-2026-07-22` instead. The SDK sets the correct beta header automatically. See [Beta headers](https://platform.claude.com/docs/en/api/beta-headers#endpoint-specific-headers).
</Note>

<Note>
  Don't combine `agent-memory-2026-07-22` with `managed-agents-2026-04-01` on a memory store request: sending both returns a `400` error. If your code sets beta headers explicitly, replace `managed-agents-2026-04-01` with `agent-memory-2026-07-22` on memory store calls rather than adding a second value. Session endpoints, including attaching a memory store to a session, still use `managed-agents-2026-04-01`.

  On July 22, 2026, the `managed-agents-2026-04-01` header adopts the same list behavior on `GET /v1/memory_stores/{memory_store_id}/memories`; sending `agent-memory-2026-07-22` opts you into that behavior now. Page cursors from requests made without the header aren't valid with it, so restart from the first page.
</Note>

## Overview

A **memory store** is a workspace-scoped collection of text documents optimized for Claude. When you attach a store to a session, it is mounted as a directory inside the session's sandbox. The agent reads and writes it with the same file tools it uses for the rest of the filesystem, and a note describing each mount is automatically added to the system prompt, telling the agent where to look. The [agent toolset](https://platform.claude.com/docs/en/managed-agents/tools) is required for these interactions; make sure to enable it during [agent creation](https://platform.claude.com/docs/en/managed-agents/agent-setup).

Each **memory** in a store is addressed by a path and can be read and edited directly through the API or the Claude Console, allowing for tuning, importing, and exporting.

Every change to a memory creates an immutable **memory version**, giving you an audit trail and point-in-time recovery for everything the agent writes.

## Create a memory store

Give the store a `name` and a `description`. The description is passed to the agent, telling it what the store contains.

<CodeGroup defaultLanguage="CLI">
  ```bash cURL
  store=$(curl -s https://api.anthropic.com/v1/memory_stores \
    -H "x-api-key: $ANTHROPIC_API_KEY" \
    -H "anthropic-version: 2023-06-01" \
    -H "anthropic-beta: agent-memory-2026-07-22" \
    -H "content-type: application/json" \
    -d '{"name": "User Preferences", "description": "Per-user preferences and project context."}')
  store_id=$(jq -r '.id' <<< "$store")
  echo "$store_id"  # memstore_01Hx...
  ```

  ```bash CLI
  store_id=$(ant beta:memory-stores create \
    --name "User Preferences" \
    --description "Per-user preferences and project context." \
    --transform id --raw-output)
  ```

  ```python Python
  store = client.beta.memory_stores.create(
      name="User Preferences",
      description="Per-user preferences and project context.",
  )
  print(store.id)  # memstore_01Hx...
  ```

  ```typescript TypeScript
  const store = await client.beta.memoryStores.create({
    name: "User Preferences",
    description: "Per-user preferences and project context."
  });
  console.log(store.id); // memstore_01Hx...
  ```

  ```csharp C#
  var store = await client.Beta.MemoryStores.Create(new()
  {
      Name = "User Preferences",
      Description = "Per-user preferences and project context.",
  });
  Console.WriteLine(store.ID);  // memstore_01Hx...
  ```

  ```go Go
  store, err := client.Beta.MemoryStores.New(ctx, anthropic.BetaMemoryStoreNewParams{
  	Name:        "User Preferences",
  	Description: anthropic.String("Per-user preferences and project context."),
  })
  if err != nil {
  	panic(err)
  }
  fmt.Println(store.ID) // memstore_01Hx...
  ```

  ```java Java
  var store = client.beta().memoryStores().create(
      MemoryStoreCreateParams.builder()
          .name("User Preferences")
          .description("Per-user preferences and project context.")
          .build()
  );
  IO.println(store.id());  // memstore_01Hx...
  ```

  ```php PHP
  use Anthropic\Client;

  $client = new Client();

  $store = $client->beta->memoryStores->create(
      name: 'User Preferences',
      description: 'Per-user preferences and project context.',
  );
  echo "{$store->id}\n"; // memstore_01Hx...
  ```

  ```ruby Ruby
  require "anthropic"

  client = Anthropic::Client.new

  store = client.beta.memory_stores.create(
    name: "User Preferences",
    description: "Per-user preferences and project context."
  )
  puts store.id # memstore_01Hx...
  ```
</CodeGroup>

The memory store `id` (`memstore_...`) is what you pass when attaching the store to a session.

### Seed it with content (optional)

Pre-load a store with reference material before any agent runs:

<CodeGroup defaultLanguage="CLI">
  ```bash cURL
  curl -s "https://api.anthropic.com/v1/memory_stores/$store_id/memories" \
    -H "x-api-key: $ANTHROPIC_API_KEY" \
    -H "anthropic-version: 2023-06-01" \
    -H "anthropic-beta: agent-memory-2026-07-22" \
    -H "content-type: application/json" \
    -d '{"path": "/formatting_standards.md", "content": "All reports use GAAP formatting. Dates are ISO-8601..."}' > /dev/null
  ```

  ```bash CLI
  ant beta:memory-stores:memories create \
    --memory-store-id "$store_id" \
    --path "/formatting_standards.md" \
    --content "All reports use GAAP formatting. Dates are ISO-8601..." \
    > /dev/null
  ```

  ```python Python
  client.beta.memory_stores.memories.create(
      store.id,
      path="/formatting_standards.md",
      content="All reports use GAAP formatting. Dates are ISO-8601...",
  )
  ```

  ```typescript TypeScript
  await client.beta.memoryStores.memories.create(store.id, {
    path: "/formatting_standards.md",
    content: "All reports use GAAP formatting. Dates are ISO-8601..."
  });
  ```

  ```csharp C#
  await client.Beta.MemoryStores.Memories.Create(store.ID, new()
  {
      Path = "/formatting_standards.md",
      Content = "All reports use GAAP formatting. Dates are ISO-8601...",
  });
  ```

  ```go Go
  _, err = client.Beta.MemoryStores.Memories.New(ctx, store.ID, anthropic.BetaMemoryStoreMemoryNewParams{
  	Path:    "/formatting_standards.md",
  	Content: anthropic.String("All reports use GAAP formatting. Dates are ISO-8601..."),
  })
  if err != nil {
  	panic(err)
  }
  ```

  ```java Java
  client.beta().memoryStores().memories().create(
      store.id(),
      MemoryCreateParams.builder()
          .path("/formatting_standards.md")
          .content("All reports use GAAP formatting. Dates are ISO-8601...")
          .build()
  );
  ```

  ```php PHP
  $client->beta->memoryStores->memories->create(
      $store->id,
      path: '/formatting_standards.md',
      content: 'All reports use GAAP formatting. Dates are ISO-8601...',
  );
  ```

  ```ruby Ruby
  client.beta.memory_stores.memories.create(
    store.id,
    path: "/formatting_standards.md",
    content: "All reports use GAAP formatting. Dates are ISO-8601..."
  )
  ```
</CodeGroup>

<Tip>
  Individual memories within the store are capped at 100 kB (\~25k tokens). A store holds a maximum of 2,000 memories. Structure memory as many small focused files, not a few large ones.
</Tip>

## Attach a memory store to a session

Memory stores are attached in the session's `resources[]` array when the [session is created](https://platform.claude.com/docs/en/managed-agents/sessions#creating-a-session). Unlike file resources, memory stores can only be attached at session creation time; adding or removing one from a running session is not supported.

Optionally include `instructions` to provide session-specific guidance for how the agent should use this store. It is shown to the agent alongside the store's `name` and `description`, and is capped at 4,096 characters.

You can configure `access` as well. It defaults to `read_write` (shown explicitly in the following example), but `read_only` is also supported.

<CodeGroup defaultLanguage="CLI">
  ```bash cURL
  curl -s https://api.anthropic.com/v1/sessions \
    -H "x-api-key: $ANTHROPIC_API_KEY" \
    -H "anthropic-version: 2023-06-01" \
    -H "anthropic-beta: managed-agents-2026-04-01" \
    -H "content-type: application/json" \
    --data @- <<EOF
  {
    "agent": "$agent_id",
    "environment_id": "$environment_id",
    "resources": [
      {
        "type": "memory_store",
        "memory_store_id": "$store_id",
        "access": "read_write",
        "instructions": "User preferences and project context. Check before starting any task."
      }
    ]
  }
  EOF
  ```

  ```bash CLI
  ant beta:sessions create <<YAML
  agent: $agent_id
  environment_id: $environment_id
  resources:
    - type: memory_store
      memory_store_id: $store_id
      access: read_write
      instructions: User preferences and project context. Check before starting any task.
  YAML
  ```

  ```python Python
  session = client.beta.sessions.create(
      agent=agent.id,
      environment_id=environment.id,
      resources=[
          {
              "type": "memory_store",
              "memory_store_id": store.id,
              "access": "read_write",
              "instructions": "User preferences and project context. Check before starting any task.",
          }
      ],
  )
  ```

  ```typescript TypeScript
  const session = await client.beta.sessions.create({
    agent: agent.id,
    environment_id: environment.id,
    resources: [
      {
        type: "memory_store",
        memory_store_id: store.id,
        access: "read_write",
        instructions: "User preferences and project context. Check before starting any task."
      }
    ]
  });
  ```

  ```csharp C#
  var session = await client.Beta.Sessions.Create(new()
  {
      Agent = agent.ID,
      EnvironmentID = environment.ID,
      Resources =
      [
          new BetaManagedAgentsMemoryStoreResourceParam
          {
              Type = "memory_store",
              MemoryStoreID = store.ID,
              Access = "read_write",
              Instructions = "User preferences and project context. Check before starting any task.",
          },
      ],
  });
  ```

  ```go Go

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