Zep

Temporality is the organising idea in Zep. When incoming information contradicts an existing fact, Zep invalidates the old fact instead of deleting it, so an application can ask Zep both what is true now and what was true on a given past date. Zep also surfaces what the company calls Observations — patterns, recurrences and co-occurrences detected in the shape of the graph, such as a customer who upgrades within two weeks of each product launch. Every fact inside a Zep graph traces back to the source episode that produced it, which is what makes an answer auditable rather than merely plausible.

Day-to-day work with Zep is deliberately small in surface area: add messages to a thread with return_context enabled, push structured business data into a user's graph with graph.add, and pull assembled context with get_user_context. Zep ships SDKs for Python, TypeScript and Go, and the vendor states Zep works with any agent framework or none at all. Around those calls, Zep adds a Memory MCP Server with seats metered per plan, webhooks, analytics, and a dashboard reporting episodes added, graphs and users created, average latency and error rate.

Zep bills on credits rather than seats or stored bytes. One credit covers an Episode up to 350 bytes, with one further credit for each additional 350 bytes or part thereof, while webhook invocations cost 1/8 credit where available and retrieval, storage, threads, users and graph storage are billed at zero credits. The self-serve Flex plan on the Zep pricing page is $1,250 per year, shown as $104 per month billed annually and as $125 per month on the plan comparison table, and includes 50,000 credits a month with overage at $25 per 10,000 credits. Flex Plus is $3,750 per year, shown as $312 per month billed annually and $375 per month on the comparison table, with 200,000 credits a month and $75 per 40,000 credits of overage.

Enterprise pricing at Zep is quoted rather than published: custom credit volumes at negotiated rates, guaranteed rate limits with an SLA, unlimited projects, custom Memory MCP Server seats, one-year API log retention, and Slack or Teams support with a dedicated account manager. Zep additionally advertises an "emerging price" for fast-growing venture-capital funded startups. Deployment scales alongside the plan — managed Zep Cloud on every tier, Cloud plus customer-held KMS keys on AWS, GCP or Azure as BYOK, and Bring Your Own Cloud where the Zep service runs inside the customer's own VPC.

The constraints in Zep deserve a close read before commitment. Zep credits roll over for 30 days on Flex and 60 days on Flex Plus, while free-plan credits do not roll over at all; the Zep FAQ also warns that Free and Flex accounts may see rate limits lowered depending on service-wide load, with lower-priority Episode processing on the free tier. Observations, webhooks, analytics and custom extraction instructions are withheld from Flex and appear only from Flex Plus upward, and Flex retains API logs for a single day against seven days on Flex Plus.

Buyers should also note a documented inconsistency on the Zep pricing page itself: the plan comparison table places SOC 2 Type II, HIPAA BAA, audit logs and the EU DPA in the Enterprise column with dashes against Flex and Flex Plus, while the Zep FAQ directly below answers that Zep is SOC 2 Type II certified and that Zep signs Data Processing Agreements with EU customers. Both statements come from Zep and both are recorded here; a compliance reviewer on a self-serve plan should get the applicable scope in writing.

Against peers in agent memory and retrieval infrastructure, Zep leans on structure and governance rather than on being the cheapest key-value memory store. Zep is built on the open-source Graphiti framework and a proprietary Context Graph Engine, publishes LoCoMo (94.7% accuracy, 155ms retrieval, 5,760 tokens) and LongMemEval (90.2% accuracy, 162ms retrieval, 4,408 tokens) benchmark figures, and maintains a dedicated mem0-alternative page. Teams that only need a scratchpad between turns will find Zep heavier than necessary; teams that must explain where an agent's belief came from, and when it changed, are the audience Zep is written for.