The remaining red Vercel status is the repository-side preview authorization gate, not a build or test failure from this branch. The status target is �ercel.com/git/authorize for the Mem0 team, which I cannot authorize from the fork.

No branch changes from me here unless a code-owned check fails or a maintainer wants the preview disabled for this PR.

LGTM — ready for human review & squash-merge

What this PR does

Fixes the ValidationException: Invalid index name warning on Memory.add() with the S3 Vectors backend (#5361). S3 Vectors forbids underscores in index names, but the entity store collection was built as {collection_name}_entities. A new _entity_collection_name(provider, collection_name) helper uses a dash ({name}-entities) for s3_vectors and keeps the underscore for every other provider; both the sync and async entity_store properties now call it.

Strengths

• Behaviour-preserving for all non-S3 providers — _entity_collection_name("qdrant", "mem0") still returns mem0_entities, so there is zero migration/back-compat risk for existing Qdrant/PGVector/etc. stores.
• Both call sites patched identically — sync Memory.entity_store and async AsyncMemory.entity_store. A repo-wide grep confirms these are the only two sites that build a _entities name, so the fix is complete.
• The S3 integration test exercises the real path (Memory.from_config → S3Vectors.create_col → boto get_index) and asserts the underscore name is not used — a genuine regression guard rather than a tautology.

Issues

Minor (all optional — none block merge):

• A one-line comment on _entity_collection_name naming the S3 underscore constraint would help future maintainers (both reviewers noted this).
• An AsyncMemory counterpart to the S3 integration test would add symmetry, though it's largely redundant: the async property calls the same module-level helper, which is already unit-tested for both branches.
• Separately, pre-existing and out of scope for this PR: AsyncMemory.reset() doesn't null self._entity_store the way sync Memory.reset() does — worth a follow-up, but unrelated to this naming fix and not something to address here.

Duplicate cluster (issue #5361 has three PRs)

This is the strongest of the three and the one I'd merge:

• fix: use valid S3 entity index names #5416 (this) — reusable helper, unit + real integration tests, MERGEABLE, behaviour-preserving.
• fix: use dash separator for S3 Vectors entity collection name #5363 (PHclaw) — inline ternary duplicated in both sites, no tests, mergeable UNKNOWN.
• fix: sanitize entity collection name for S3 Vectors (no underscores) #5498 (HrushiYadav) — .replace("_","-") also rewrites underscores inside the user's collection name; but S3's main collection uses collection_name verbatim, so that diverges the entity index from the main one without fixing the root cause, and its test is heavily mocked.

Recommend squash-merging #5416 and closing #5363 and #5498 as duplicates.

Evidence

• CI: build_mem0 3.10 / 3.11 / 3.12 pass, changelog_check pass, check_changes pass, license/cla signed. The red Vercel status is the repo-side preview-authorization gate, not a build/test failure — your read in the thread is correct.
• Targeted tests: hatch -e dev_py_3_12 run pytest tests/vector_stores/test_s3_vectors.py tests/test_memory.py -v → 52 passed in 0.74s (all three new tests pass).
• Red-green proof: reverting mem0/memory/main.py to main makes test_memory_entity_store_uses_s3_valid_index_name fail with AssertionError: 'test-index-entities' in [..., 'test-index_entities'] (and the helper unit tests ImportError); restoring the fix → 52 passed. The regression test bites.
• Lint: ruff check on the three changed files → All checks passed!
• Linked issue: Warning output to log when calling Memory.add() using s3 vectors backend #5361 — addresses the reported root cause (underscore in the S3 index name) precisely.
• Cross-package check: the TS OSS SDK has the same ${collectionName}_entities line, but ships no S3 Vectors provider, so it has no equivalent bug — no TS change needed.
• Could NOT verify: live S3 Vectors API behaviour (boto is mocked) — the AWS underscore constraint comes from the issue report plus S3 docs, verified here via code tracing only.

Assessment

Ready to merge: Yes (squash) · Est. human time: ~3 min
Correct, minimal, behaviour-preserving fix with a red-green-proven regression test and green CI. Just needs a squash-merge and closing the two duplicate PRs.