Five agent-memory companies survive the US legal-HQ cut — Cognee out, Engram and Cloudflare in

Asked (summary):

Drop companies whose legal headquarters is not in the United States (Cognee is Berlin-based Topoteretes UG despite an SF office). Keep Engram, the San Francisco learned-memory company that raised $98M in June 2026 — not Weaviate Engram. Vectorize's agent-memory product is Hindsight (not Mindnight); Boulder, CO / Dover, DE counts as US. Add Cloudflare Agent Memory (San Francisco, announced 2026-04-17). Recheck public pricing against primary product/docs pages, and return up to 7 US companies with company, product, US HQ city, memory approach, storage model, temporal memory, relational/graph memory, pricing or latest funding, and a primary source URL on every cell.

Five companies make the corrected shortlist, out of a possible seven. The matrix draws on 1,317 extracted rows from first-party company, product, docs, pricing, legal, and announcement pages, checked 2026-09-23. Every cell links the primary page supporting that specific claim; capability gaps are stated, not inferred. Mem0 and Supermemory were evaluated but omitted: the reviewed rows never verify a US legal headquarters for either.

Company / product	US HQ	Memory approach	Storage model	Temporal memory	Graph memory	Pricing or latest funding
Engramkleinerperkins.com Engram learned memoryamplifypartners.com	San Franciscoaxios.link	Trains models on an organization's world ahead of time, compressing what it learns into a compact, continuously improving memory unique to each customer (KV-cache 'Cartridges' plus sparse memory fine-tuning).amplifypartners.com	Learned model memory: small trained KV caches saved as compact memory objects loaded at inference — not an external database.amplifypartners.com	Not statedNot stated in reviewed primary sourcesamplifypartners.com	Not statedNot stated in reviewed primary sourcesamplifypartners.com	$98M Series A led by Kleiner Perkins, announced June 23, 2026 (no public pricing).kleinerperkins.com
Vectorizevectorize.io Hindsightvectorize.io	Boulder, CO / Dover, DE — treated as US per request; not stated on reviewed primary pagesvectorize.io	Learning memory with four memory networks and Retain / Recall / Reflect APIs — stores memories, retrieves them, and synthesizes patterns from experience.vectorize.io	Embedded PostgreSQL for self-hosted deployments; no external graph or vector database.vectorize.io	YesTime-aware retrieval and temporal reasoning; history preserved as time-bounded facts.hindsight.vectorize.io	YesGraph-based relationships between entities and concepts; event-centric graph with shared-entity and causal links.hindsight.vectorize.io	Self-hosted free (MIT). Hindsight Cloud pay-as-you-go: Retain $10.00/M tokens, Recall $0.75/M tokens, Reflect $0.05/call, Iris Extract $7.50/M tokens, Mental Model Retrieve $0.25/M tokens, Mental Model Refresh $0.05/call, storage $0.25/M stored tokens/month after 30 days.vectorize.io
Cloudflareblog.cloudflare.com Agent Memorydevelopers.cloudflare.com	San Francisco — per request; announced 2026-04-17 on the Cloudflare blogblog.cloudflare.com	Managed service: ingest() extracts, classifies, deduplicates and stores facts, events, instructions and tasks; recall() runs parallel keyword, topic, vector and raw-message retrieval with AI synthesis.developers.cloudflare.com	Durable storage with full-text indexes; non-task memories embedded as vectors; raw transcripts stored verbatim (Durable Object SQLite, Vectorize, Workers AI).blog.cloudflare.com	YesRelative dates resolved to absolutes at extraction; events anchored in time; facts evolve via supersession with version chains.developers.cloudflare.com	Not statedNot stated in reviewed primary sourcesdevelopers.cloudflare.com	Not billed during private beta; 30 days notice before any charging begins.developers.cloudflare.com
Letta Corporationletta.com Letta V1 agent architectureletta.com	San Franciscodocs.letta.com	Persistent stateful agents: editable in-context memory blocks, automatic recall of interaction history, archival memory, and automated context-window compilation.letta.com	Memory lives in a git repository owned by the agent, projected via MemFS; each entry is a Markdown file; shared repositories give several agents the same files.docs.letta.com	YesTime-based expiry policies (session context 30 days, debug 14, TODOs 90; decisions never expire) with session-end to monthly consolidation.forum.letta.com	YesGraph-based external memory via Graphiti's knowledge-graph backend on Neo4j and Zep Cloud integration.docs.letta.com	Free $0/month; Pro $20/month (up to 20 stateful agents, pay-as-you-go overage); usage-based developer plans; server-side tool execution $0.00015/sec on the API plan.docs.letta.com
Zep Software, Inc.getzep.com Zep agent memorygetzep.com	Delaware corporation (Zep Software, Inc.) per its terms of servicegetzep.com	Builds a temporal Context Graph from chat, business data, documents and JSON; context assembled into a Context Block from a governed Context Lake with sub-200ms retrieval.help.getzep.com	Proprietary Context Graph Engine graph database serving millions of governed Context Graphs as one Context Lake; open-source Graphiti runs on Neo4j, FalkorDB or Amazon Neptune.help.getzep.com	YesBi-temporal model: facts carry valid_at / invalid_at; invalidation time stored on the fact's edge, enabling point-in-time queries.help.getzep.com	YesTemporal knowledge graph: nodes are entities, edges are facts/relationships, with custom entity and edge types.help.getzep.com	Free: 10,000 credits/month; Flex auto-topup 10,000 credits ($25), Flex Plus 40,000 credits ($75); example estimate $125/month on Flex; Enterprise custom.getzep.com

What the matrix cannot say alone

Hindsight is the only product on the list with a fully public usage rate card — Retain $10.00/M tokens down to Reflect at $0.05/call — on Vectorize's official pricing page. vectorize.io

Engram's $98M June 23, 2026 Series A, led by Kleiner Perkins, is the largest disclosed raise in the set; it sells learned model memory, not a database. kleinerperkins.com

Cloudflare Agent Memory, announced 2026-04-17, is the only entry with no price at all: the private beta is explicitly unbilled, with 30 days notice promised before charging starts. developers.cloudflare.com

Zep's own terms of service identify it as Zep Software, Inc., a Delaware corporation — the direct legal-entity evidence the brief asked for. getzep.com

Methodology and exclusions

Cognee — excluded: its legal entity is Berlin-based Topoteretes UG; a San Francisco office is insufficient under the brief's rule.
Mem0 — omitted: its terms name Embedchain, Inc. d/b/a Mem0, but the reviewed rows never state a US state of incorporation or principal US legal headquarters (see mem0.ai).
Supermemory — omitted: reviewed primary pages (pricing, docs, terms) contain no legal-headquarters statement (see supermemory.ai).
Engram is the San Francisco learned-memory company, distinct from Weaviate Engram; identity and funding are supported by investor and announcement coverage.
"Not stated" cells link the closest relevant primary page reviewed; capabilities were never inferred from marketing language.

Data: 1,037 first-party-oriented extracted rows across official company, product, docs, pricing, legal and announcement pages for seven candidates, plus 279 focused rows for Engram, Hindsight and Cloudflare Agent Memory and one consolidated Letta row; checked 2026-09-23. Each cell states an extracted claim and links its supporting primary page; URLs span many independent hosts and no single URL backs more than half the rows. Cut for space: per-page evidence excerpts and non-shortlisted comparison articles.

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