Claude agent memory migration: prepare for the July 22 API behavior change

# Claude agent memory migration: prepare for the July 22 API behavior change

Quick answer

On **July 22, 2026**, Claude memory-store list requests that still use `managed-agents-2026-04-01` adopt the behavior already available through `agent-memory-2026-07-22`. This is not only a header rename. The list contract changes in five ways:

| Area | New behavior |

|---|---|

| Header | Memory-store endpoints use `agent-memory-2026-07-22`; sending it together with `managed-agents-2026-04-01` returns `400` |

| Ordering | Results use a stable server-defined order; `order_by` and `order` are ignored |

| Depth | Only `0`, `1`, or omission is accepted; other values return `400` |

| Prefix | `path_prefix` must end with `/` and matches whole path segments |

| Pagination | Cursors created under the old behavior cannot be reused with the new header |

If you call `/v1/memory_stores` through a current Anthropic SDK, upgrade to the documented minimum version and remove explicit beta overrides. If you use raw HTTP, replace the header on memory-store requests, normalize list parameters, discard saved cursors, and test the new contract before July 22.

Who this is for

This guide is for teams using Claude Managed Agents memory stores through the REST API, `ant` CLI, or Anthropic SDKs. It matters most when an application lists memories for an admin screen, synchronizes them into another store, walks hierarchical prefixes, or saves pagination cursors between jobs.

The change is specific to `/v1/memory_stores` and its sub-resources. Agent, session, and environment endpoints still use `managed-agents-2026-04-01`. It is also separate from Claude Code project instruction files or a local `MEMORY.md`.

If your wider agent runtime needs a configuration inventory, adapt the layered approach in the [AGENTS.md, CLAUDE.md, and Copilot instructions guide](/blogs/agents-md-vs-claude-md-copilot-instructions/). For provider-level cutovers, reuse the canary and rollback discipline from the [GitHub Models migration checklist](/blogs/github-models-retirement-migration-checklist/).

Why July 22 can break existing clients

Anthropic introduced `agent-memory-2026-07-22` on July 2 so developers could test the new list behavior early. On July 22, requests that still send the older Managed Agents header to memory-store endpoints receive the same behavior.

Four common assumptions can then fail:

• A tree browser sends `depth=2` and starts receiving `400` responses.
• A sync job depends on `order_by=path&order=asc`, even though those fields are now ignored.
• A prefix such as `/projects/acme` is treated like a raw substring instead of the directory prefix `/projects/acme/`.
• A worker resumes from a cursor issued under the previous behavior and gets an invalid or inconsistent pagination flow.

The current SDK floors documented by Anthropic are Python `0.116.0`, TypeScript `0.110.0`, Go `1.56.0`, Java `2.48.0`, Ruby `1.55.0`, PHP `0.36.0`, C# `12.35.0`, and CLI `1.16.0`. These ve