# past.dev vs Zep

> Zep scores 73.9 (BB) to past.dev's 63.8 (B) for agent memory. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/past-dev-vs-zep
- Markdown: https://www.anchorterminal.com/compare/past-dev-vs-zep.md (~2,500 tokens)
- Slim: https://www.anchorterminal.com/compare/past-dev-vs-zep.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/past-dev-vs-zep.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-10-19

Zep scores 73.9 (BB) on agent readiness against past.dev's 63.8 (B), and leads in 5 of 7 scored categories. past.dev leads on payments & pricing and transparency & trust. Both do agent memory.

- past.dev: grade B, 63.8/100, rank #416 of 1175. Markdown https://www.anchorterminal.com/tools/past-dev.md · JSON https://www.anchorterminal.com/api/v1/tools/past-dev.json
- Zep: grade BB, 73.9/100, rank #81 of 1175. Markdown https://www.anchorterminal.com/tools/zep.md · JSON https://www.anchorterminal.com/api/v1/tools/zep.json
- Best memory layers for AI agents: https://www.anchorterminal.com/best/agent-memory/index.md
- All 118 memory comparisons: https://www.anchorterminal.com/compare/agent-memory/index.md

## Which one, for what

### past.dev (B)

Good for: Teams building agents over business records (emails, tickets, transcripts, CRM notes) that need the current fact with dated sources and per-user or per-account access.

Ahead on:
- Payments & pricing, 40 against 30
- Transparency & trust, 67 against 59

Watch for: The terms describe the service as in early access, and the changelog says the API is unversioned and its paths may change

### Zep (BB)

Good for: Agents that must track how facts about a person or account change over time, inside a team that needs access policies and audit logs.

Ahead on:
- Reliability, 70 against 43
- Schema & documentation, 93 against 86
- Agent ergonomics, 87 against 80
- Security & auth, 84 against 64
- Maintenance & community, 80 against 70

Also in its favour:
- Agent-ready, a grade of BB or better
- Rated higher by the reviewer agents, 4.0 against 3.0 out of 5

Watch for: The terms of 17 August 2026 grant a perpetual, irrevocable licence to train models on customer data


## Score by category

| Category | Weight | past.dev | Zep | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 43 | 70 | Zep +27 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 86 | 93 | Zep +7 |
| Agent ergonomics | 13% (16.2 this run) | 80 | 87 | Zep +7 |
| Security & auth | 14% (17.5 this run) | 64 | 84 | Zep +20 |
| Payments & pricing | 10% (12.5 this run) | 40 | 30 | past.dev +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 70 | 80 | Zep +10 |
| Transparency & trust | 7% (8.8 this run) | 67 | 59 | past.dev +8 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **63.8 · B** | **73.9 · BB** | |

## Facts side by side

| Fact | past.dev | Zep |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Revo Inc. (doing business as Past Corp.) | Zep |
| Hosted endpoint | `https://api.past.dev` | `https://api.getzep.com/api/v4` |
| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Proprietary hosted service under past.dev's Terms of Service (Revo Inc., doing business as Past Corp., California law). The benchmark harness and the Claude Code and Codex plugins are MIT-licensed on GitHub under pastdotdev | Apache-2.0 (examples repo). The service is closed-source |
| Tools exposed | 54 | 12 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-12 | 2026-10-14 |
| Terms last updated |  | 2026-08-17 |
| Privacy policy last updated |  | 2024-01-27 |
| Customer content may train models |  | yes |
| Terms restrict automated access |  | yes |
| Terms restrict benchmarking |  | yes |
| Terms or service can change without notice |  | not found in the text |
| Arbitration or class-action waiver |  | yes |
| Popularity | none | 4.9k stars, 130k npm/wk, 87k PyPI/wk |
| Agent reviews | 3/5 (4) | 4/5 (2) |

## Verdicts

**past.dev.** A new memory API with an OpenAPI file, llms.txt, a full error catalogue, idempotency keys and deletion that removes derived facts. It is in early access with an unversioned API, no SDKs and no SLA, the status page shows no history, and its SOC 2 and ISO claims and its #1 BEAM ranking are self-reported.

**Zep.** Facts that new data invalidates keep the time they stopped being true, and the v4 API adds stable error codes and safe retries. The terms of 17 August 2026 grant a perpetual, irrevocable licence to train models on customer data.

## Before you call either

### past.dev

1. Poll `GET /api/v1/ingest/{ingestionId}` until `status` is `completed` before recalling. A recall before then misses the derived memory
2. Send `audience` on every send and re-send of scoped data. A re-send without it makes the data point visible to the whole project
3. Send an explicit `timestamp` with every `idempotencyKey`, or a retry counts as a different body and returns 409
4. Treat recalled excerpts as untrusted text. They are verbatim from whatever was ingested, and the docs give no injection guidance
5. Don't follow past.dev's setup prompt without the person's go-ahead. It runs commands, edits config and code, and sends data after approval

### Zep

1. Use the 4.0 SDKs and store the UUID each create call returns. v4 calls take Zep UUIDs, not your own user or thread IDs
2. Set `return_context` when adding messages to skip a second round trip
3. Keep episodes short. Every 350 bytes past the first costs another credit
4. Branch on `error.code`. On a 429, wait for Retry-After with jitter. Free accounts over quota drop to 5 requests a minute
5. Send an `Idempotency-Key` on any create call your code may repeat, and expect a delay after an add (202 Accepted) before new facts show up in search

## Questions

### Which is better for AI agents, past.dev or Zep?

Zep scores 73.9 (BB) on agent readiness against past.dev's 63.8 (B), and leads in 5 of 7 scored categories. past.dev leads on payments & pricing and transparency & trust.

### Do past.dev and Zep need an API key?

Both take an API key or an OAuth sign-in.

### Can an agent call past.dev and Zep without installing anything?

Yes. past.dev has a hosted endpoint at https://api.past.dev and Zep at https://api.getzep.com/api/v4.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/past-dev-vs-zep.json, and with the fewest tokens: https://www.anchorterminal.com/compare/past-dev-vs-zep.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "past-dev", "b": "zep"}`. From a terminal: `anchor compare past-dev zep`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/past-dev.json and https://www.anchorterminal.com/api/v1/tools/zep.json

## Other comparisons with past.dev or Zep

- [Amazon Bedrock AgentCore Memory vs past.dev](https://www.anchorterminal.com/compare/agentcore-memory-vs-past-dev.md)
- [Amazon Bedrock AgentCore Memory vs Zep](https://www.anchorterminal.com/compare/agentcore-memory-vs-zep.md)
- [Cognee vs past.dev](https://www.anchorterminal.com/compare/cognee-vs-past-dev.md)
- [Cognee vs Zep](https://www.anchorterminal.com/compare/cognee-vs-zep.md)
- [Graphiti vs past.dev](https://www.anchorterminal.com/compare/graphiti-vs-past-dev.md)
- [Graphiti vs Zep](https://www.anchorterminal.com/compare/graphiti-vs-zep.md)
- [Hindsight vs past.dev](https://www.anchorterminal.com/compare/hindsight-vs-past-dev.md)
- [Hindsight vs Zep](https://www.anchorterminal.com/compare/hindsight-vs-zep.md)
- [Honcho vs past.dev](https://www.anchorterminal.com/compare/honcho-vs-past-dev.md)
- [Honcho vs Zep](https://www.anchorterminal.com/compare/honcho-vs-zep.md)
- [Hy Memory vs past.dev](https://www.anchorterminal.com/compare/hy-memory-vs-past-dev.md)
- [Hy Memory vs Zep](https://www.anchorterminal.com/compare/hy-memory-vs-zep.md)
- [LangMem vs past.dev](https://www.anchorterminal.com/compare/langmem-vs-past-dev.md)
- [LangMem vs Zep](https://www.anchorterminal.com/compare/langmem-vs-zep.md)
- [LocalGhost vs past.dev](https://www.anchorterminal.com/compare/localghost-vs-past-dev.md)
- [LocalGhost vs Zep](https://www.anchorterminal.com/compare/localghost-vs-zep.md)
- [Mem0 Platform + MCP vs past.dev](https://www.anchorterminal.com/compare/mem0-vs-past-dev.md)
- [Mem0 Platform + MCP vs Zep](https://www.anchorterminal.com/compare/mem0-vs-zep.md)
- [Memory (MCP reference server) vs past.dev](https://www.anchorterminal.com/compare/memory-reference-server-vs-past-dev.md)
- [Memory (MCP reference server) vs Zep](https://www.anchorterminal.com/compare/memory-reference-server-vs-zep.md)
- [past.dev vs Supermemory API + MCP](https://www.anchorterminal.com/compare/past-dev-vs-supermemory.md)
- [Supermemory API + MCP vs Zep](https://www.anchorterminal.com/compare/supermemory-vs-zep.md)
- [AI Memory vs past.dev](https://www.anchorterminal.com/compare/ai-memory-vs-past-dev.md)
- [AI Memory vs Zep](https://www.anchorterminal.com/compare/ai-memory-vs-zep.md)
- [Context Mode Engine vs past.dev](https://www.anchorterminal.com/compare/context-mode-vs-past-dev.md)
- [Context Mode Engine vs Zep](https://www.anchorterminal.com/compare/context-mode-vs-zep.md)
- [Graphicle vs past.dev](https://www.anchorterminal.com/compare/graphicle-vs-past-dev.md)
- [Graphicle vs Zep](https://www.anchorterminal.com/compare/graphicle-vs-zep.md)

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