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.
All Managed Agents API requests require the managed-agents-2026-04-01 beta header. The SDK sets the beta header automatically.
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 container. 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 is required for these interactions; make sure to enable it during agent creation.
Each memory in a store is addressed by a path and can be read and edited directly via the API or 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.
Give the store a name and a description. The description is passed to the agent, telling it what the store contains.
store_id=$(ant beta:memory-stores create \
--name "User Preferences" \
--description "Per-user preferences and project context." \
--transform id --raw-output)The memory store id (memstore_...) is what you pass when attaching the store to a session.
Pre-load a store with reference material before any agent runs:
ant beta:memory-stores:memories create \
--memory-store-id "$store_id" \
--path "/formatting_standards.md" \
--content "All reports use GAAP formatting. Dates are ISO-8601..." \
> /dev/nullIndividual memories within the store are capped at 100 kB (~25k tokens). Structure memory as many small focused files, not a few large ones.
Memory stores are attached in the session's resources[] array when the session is created. Unlike file and repository 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.
ant beta:sessions create <<YAML
agent: $agent_id
environment_id: $environment_id
resources:
- type: memory_store
memory_store_id: $store_id
access: read_write
instructions: User preferences and project context. Check before starting any task.
YAMLMemory stores attach with read_write access by default. If the agent processes untrusted input (user-supplied prompts, fetched web content, or third-party tool output), a successful prompt injection could write malicious content into the store. Later sessions then read that content as trusted memory. Use read_only for reference material, shared lookups, and any store the agent does not need to modify.
A maximum of 8 memory stores are supported per session. Attach multiple stores when different parts of memory have different owners or access rules. Common reasons:
Each attached store is mounted inside the session's container as a directory under /mnt/memory/, and the agent reads and writes it with the standard agent toolset. Writes are persisted back to the store and stay in sync across sessions that share it. A short description of each mount (path, access mode, store description, and any instructions) is automatically added to the system prompt.
access is enforced at the filesystem level: a read_only mount rejects writes, while writes to a read_write mount produce memory versions attributed to the session.
The agent's reads and writes appear in the event stream as ordinary agent.tool_use and agent.tool_result events for whichever tool touched the mount.
Memory stores can be managed directly via the API. Use this for building review workflows, correcting bad memories, or seeding stores before any session runs.
List the memories in a store, optionally filtered by path_prefix to browse a path like a directory:
ant beta:memory-stores:memories list \
--memory-store-id "$store_id" \
--path-prefix "/" --order-by path --depth 2See the List memories reference for full parameters and response schema.
Fetching an individual memory returns the full content.
ant beta:memory-stores:memories retrieve \
--memory-store-id "$store_id" \
--memory-id "$mem_id"See the Retrieve a memory reference for full parameters and response schema.
memories.create creates a memory at a given path. Create does not overwrite; to change an existing memory, use memories.update.
mem=$(ant beta:memory-stores:memories create \
--memory-store-id "$store_id" \
--path "/preferences/formatting.md" \
--content "Always use tabs, not spaces." \
--format json)
mem_id=$(jq -r '.id' <<< "$mem")
mem_sha=$(jq -r '.content_sha256' <<< "$mem")See the Create a memory reference for full parameters and response schema.
memories.update modifies an existing memory by ID. You can change content, path (a rename), or both. The example renames a memory to an archive path:
ant beta:memory-stores:memories update \
--memory-store-id "$store_id" \
--memory-id "$mem_id" \
--path "/archive/2026_q1_formatting.md" \
> /dev/nullSee the Update a memory reference for full parameters and response schema.
To avoid clobbering a concurrent write, pass a content_sha256 precondition. The update only applies if the stored content hash still matches the one you read; on mismatch, re-read the memory and retry against the fresh state.
ant beta:memory-stores:memories update \
--memory-store-id "$store_id" \
--memory-id "$mem_id" \
--content "CORRECTED: Always use 2-space indentation." \
--precondition "{type: content_sha256, content_sha256: $mem_sha}" \
> /dev/nullant beta:memory-stores:memories delete \
--memory-store-id "$store_id" \
--memory-id "$mem_id" \
> /dev/nullSee the Delete a memory reference for full parameters and response schema.
Every mutation to a memory creates an immutable memory version (memver_...). Use the version endpoints to audit who changed what and when, to inspect or restore a prior snapshot, and to scrub sensitive content out of history with redact.
Versions belong to the store (not the individual memory) and survive even after the memory itself is deleted, so the audit trail stays complete. Versions are retained for 30 days; however, the recent versions are always kept regardless of age, so memories that change infrequently might retain history beyond 30 days. The live memories.retrieve call always returns the latest version; the version endpoints give you the retained history.
There is no dedicated restore endpoint; to roll back, retrieve the version you want and write its content back with memories.update (or memories.create if the parent memory has been deleted, because versions outlive their parent).
Past memory versions might be deleted after 30 days. To preserve memory history for longer, export versions via the API.
List version history for a store, newest first. The example filters to a single memory's history:
versions=$(ant beta:memory-stores:memory-versions list \
--memory-store-id "$store_id" \
--memory-id "$mem_id" \
--format json)
jq -r '.data[] | "\(.id): \(.operation)"' <<< "$versions"
version_id=$(jq -r '.data[1].id' <<< "$versions")See the List memory versions reference for full parameters and response schema.
Fetching an individual version returns the same fields as the list response plus the full content body.
ant beta:memory-stores:memory-versions retrieve \
--memory-store-id "$store_id" \
--memory-version-id "$version_id"See the Retrieve a memory version reference for full parameters and response schema.
Redact scrubs content out of a historical version while preserving the audit trail (who did what, when). Use it for compliance workflows such as removing leaked secrets, PII, or user deletion requests.
A version that is the current head of a live memory cannot be redacted. Write a new version first (or delete the memory), then redact the old one.
ant beta:memory-stores:memory-versions redact \
--memory-store-id "$store_id" \
--memory-version-id "$version_id"See the Redact a memory version reference for full parameters and response schema.
In addition to create, memory stores support retrieve, update, list, archive, and delete.
List stores in the workspace. Archived stores are excluded by default; pass include_archived: true to include them.
ant beta:memory-stores list --include-archivedSee the List memory stores reference for full parameters and response schema.
Archiving makes a store read-only and prevents it from being attached to new sessions. Archiving is one-way; there is no unarchive.
ant beta:memory-stores archive --memory-store-id "$store_id"See the Archive a memory store reference for full parameters and response schema.
To permanently remove a store along with all of its memories and versions, use memory_stores.delete.
Default capacity and rate limits apply to memory stores while this feature is in beta. Contact support if you need higher limits.
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