# Maximem Synap vs Letta Letta is the fully open-source agent framework with OS-inspired tiered memory. Maximem Synap is the agentic context management system that scored 92% on LongMemEval and 93.2% on LoCoMo with 15ms retrieval, designed to plug into any framework. [Start free — no credit card](https://synap.maximem.ai/?utm_source=site&utm_medium=compare_hero&utm_campaign=letta)[Try it live — no signup](https://www.maximem.ai/playground) Strong Partial / Limited No / Weak Not verified / Not published ### Head-to-Head Comparison Feature Maximem Synap Letta LongMemEval (independently verified) Best 92% Not applicable Not verified LongMemEval (self-reported) Best 92% Not applicable Not published P50 retrieval latency Best 15ms Not applicable Not published (LLM-dependent tool calls) Open-source eval harness Best Full config published No No Context management paradigm Best Active: system captures, compacts, recalls Partial Agent-managed: LLM manages its own tiers Ingestion approach Best Extract-first: multi-stage pipeline No Agent-directed via tool calls Pipeline customization per agent Best Custom architecture per agent via YAML Partial Agents self-edit, but pipeline is universal Data connectors Best Connectors for structured data sources No Text ingestion only Memory types Best 5 structured: facts, preferences, episodes, emotions, temporal Partial Generic blocks in 3 tiers Context compaction Best 4 strategies + quality validation score Partial Agent-directed archival (LLM decides) Contradiction handling Best Explicit detection & resolution (HITL when needed) Partial Agent self-edits Temporal awareness Best Full bitemporal awareness Partial Timestamps on operations Entity resolution Best Automatic, multi-strategy No No built-in entity resolution Memory scoping mechanism Best Intelligent & automated No Manual (agent tool calls) Scoping levels Best Org hierarchy: User → Customer → Client Partial Per-agent (core + archival) Organizational memory Best Customer + Client scopes No Per-agent only Context sharing in agent-swarm systems Best Native: shared context + agent-specific memories Best Native coordinator + sub-agents SDK languages Best Python + JavaScript Best Python + TypeScript Framework integrations Best 22 frameworks Partial Own platform Observability Best Dashboard: pipelines, memories, entity queue Best White-box: full prompt + memory transparency Last updated: April 2026. Benchmarks sourced from Synap's open-source LongMemEval and LoCoMo harness and vendor documentation. Feature availability may change. 01/Why Synap ## Why Teams Choose Maximem Synap Over Letta ### Different design philosophies. Letta gives the agent control over its own memory. The LLM decides what to store, archive, and retrieve through tool calls. Synap takes the opposite approach: the system manages context so the agent does not have to. The right choice depends on what you are building. ### When the agent manages its own memory, the agent needs to be good at it. Letta's self-editing model means memory quality depends on the LLM's judgment about what to keep and what to discard. In production, this creates a circular dependency: the agent that needs better context is the same agent deciding what context to save. Synap removes that dependency. A multi-stage pipeline extracts structured knowledge (facts, preferences, episodes, temporal events, emotions) before the agent ever sees it. ### Entity resolution is a system problem, not an agent problem. Letta has no built-in entity resolution. If "Sarah," "Sarah Chen," and "SC" appear across conversations, the agent needs to figure that out on its own. Synap resolves entities automatically during ingestion with multiple matching strategies. The agent never needs to handle disambiguation. ### Scope isolation for SaaS builders. Letta's memory is per-agent. There is no built-in organizational memory. If you are building a SaaS product where multiple users interact with agents and you need tenant isolation, that is your responsibility to architect. Synap provides a nested scope chain (User → Customer → Client) with built-in isolation and organizational memory sharing. ### Where Letta has the edge. Letta is fully open-source under Apache 2.0. You can self-host the entire product, inspect every line of code, and modify the agent's memory behavior at any level. Letta's white-box transparency (full visibility into prompt construction and memory state at every step) is the most thorough debugging model in this space. Letta also supports native multi-agent coordination with sub-agents sharing state. Benchmark note: Letta has not published a LongMemEval score. We will update this page when scores become available for independent comparison. ## Compare Synap against other alternatives [Synap vs Mem0](https://www.maximem.ai/compare/maximem-synap-vs-mem0)[Synap vs Zep](https://www.maximem.ai/compare/maximem-synap-vs-zep)[Synap vs Supermemory](https://www.maximem.ai/compare/maximem-synap-vs-supermemory)[Synap vs Cognee](https://www.maximem.ai/compare/maximem-synap-vs-cognee)[Synap vs Evermind](https://www.maximem.ai/compare/maximem-synap-vs-evermind)[Best Letta alternatives](https://www.maximem.ai/letta-alternatives)[Synap vs all alternatives](https://www.maximem.ai/compare/maximem-synap-vs-mem0-vs-zep-vs-letta-vs-supermemory-vs-cognee-vs-evermind) ## Ready to evaluate Synap against Letta? Free tier, no credit card. Open-source SDK and a published eval harness. [Start free — no credit card](https://synap.maximem.ai/?utm_source=site&utm_medium=compare_footer&utm_campaign=letta)[Try it live — no signup](https://www.maximem.ai/playground) ## Frequently Asked Questions ### Is Maximem Synap a Letta alternative? Synap and Letta solve adjacent problems with opposite philosophies. Letta is an agent framework where the LLM manages its own tiered memory via tool calls. Synap is an agentic context management layer where the system manages context automatically so any agent framework (LangChain, CrewAI, AutoGen, etc.) can consume it. ### Does Synap work alongside Letta agents? Synap plugs into any agent framework via its Python and JavaScript SDKs. If you are running Letta agents, you can use Synap as the underlying context layer and let Letta focus on orchestration. ### When should I pick Letta over Synap? Pick Letta if you need full open-source self-hosting under Apache 2.0, white-box transparency into prompt construction, and native multi-agent coordination as a framework. Pick Synap if you need a context layer that plugs into any framework and delivers verified 92% LongMemEval and 93.2% LoCoMo accuracy with 15ms retrieval. [Learn more about Maximem Synap](https://www.maximem.ai/synap)·[Best Letta alternatives](https://www.maximem.ai/letta-alternatives)·[Compare Synap against all alternatives](https://www.maximem.ai/compare/maximem-synap-vs-mem0-vs-zep-vs-letta-vs-supermemory-vs-cognee-vs-evermind)·[How we measure memory quality](https://www.maximem.ai/measuring-agent-memory)·[What switching from Letta actually costs](https://www.maximem.ai/tco?mode=switch&from=letta_pro)·[Or build it yourself?](https://www.maximem.ai/build-vs-buy-agent-memory) --- Source: [https://www.maximem.ai/compare/maximem-synap-vs-letta](https://www.maximem.ai/compare/maximem-synap-vs-letta)