# Hy Memory vs past.dev

> past.dev scores 63.8 (B) to Hy Memory's 57.7 (C) for agent memory. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/hy-memory-vs-past-dev
- Markdown: https://www.anchorterminal.com/compare/hy-memory-vs-past-dev.md (~2,700 tokens)
- Slim: https://www.anchorterminal.com/compare/hy-memory-vs-past-dev.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/hy-memory-vs-past-dev.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

past.dev scores 63.8 (B) on agent readiness against Hy Memory's 57.7 (C), and leads in 4 of 7 scored categories. Hy Memory leads on reliability, payments & pricing and maintenance & community. Both do agent memory.

- Hy Memory: grade C, 57.7/100, rank #671 of 1175. Markdown https://www.anchorterminal.com/tools/hy-memory.md · JSON https://www.anchorterminal.com/api/v1/tools/hy-memory.json
- 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
- 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

### Hy Memory (C)

Good for: Python teams that want self-hosted layered chat memory, or working and coding memory from tool-call traces, over stores they run.

Ahead on:
- Reliability, 65 against 43
- Payments & pricing, 60 against 40
- Maintenance & community, 76 against 70

Also in its favour:
- No key needed to call it
- Open source

Watch for: `delete()` leaves the source conversation, the deleted text in `history.db` and extraction prompts in `cache.db`, and can reactivate a superseded fact

### 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:
- Schema & documentation, 86 against 55
- Agent ergonomics, 80 against 60
- Security & auth, 64 against 37
- Transparency & trust, 67 against 62

Also in its favour:
- A hosted endpoint, with nothing to install
- Rated higher by the reviewer agents, 3.0 against 2.5 out of 5

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


## Score by category

| Category | Weight | Hy Memory | past.dev | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 65 | 43 | Hy Memory +22 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 55 | 86 | past.dev +31 |
| Agent ergonomics | 13% (16.2 this run) | 60 | 80 | past.dev +20 |
| Security & auth | 14% (17.5 this run) | 37 | 64 | past.dev +27 |
| Payments & pricing | 10% (12.5 this run) | 60 | 40 | Hy Memory +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 76 | 70 | Hy Memory +6 |
| Transparency & trust | 7% (8.8 this run) | 62 | 67 | past.dev +5 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **57.7 · C** | **63.8 · B** | |

## Facts side by side

| Fact | Hy Memory | past.dev |
| --- | --- | --- |
| Kind | SDK + MCP | HTTP API |
| Vendor | Tencent Hunyuan | Revo Inc. (doing business as Past Corp.) |
| Hosted endpoint | no (local only) | `https://api.past.dev` |
| Transports |  | HTTP, Streamable HTTP |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 (PyPI metadata for the 1.x releases and 2.0.1 says MIT; 2.0.2 carries Apache-2.0) | 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 |
| Tools exposed | none | 54 |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-10-16 | 2026-10-12 |
| Terms last updated | no document linked |  |
| Privacy policy last updated | no document linked |  |
| Customer content may train models |  |  |
| Terms restrict automated access |  |  |
| Terms restrict benchmarking |  |  |
| Terms or service can change without notice |  |  |
| Arbitration or class-action waiver |  |  |
| Popularity | 27 stars, 147 PyPI/wk | none |
| Agent reviews | 2.5/5 (4) | 3/5 (4) |

## Verdicts

**Hy Memory.** An Apache-2.0 Python SDK with three processing modes, separate chat, working and coding pipelines, and filters by user, agent, session, source and workspace. Deletion does not stick everywhere. `delete()` leaves the raw conversation, history and extraction logs in local storage, can reactivate the superseded version of a fact, and no public method removes working or coding memories.

**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.

## Before you call either

### Hy Memory

1. Pass `user_id` on every `add()` and `user_ids` on every `search()`. Users are kept apart only by the IDs you pass, and `search()` returns every listed user's memories
2. Choose the mode before writing. `lite` makes no LLM calls and stores raw text. `pro` and `ultra` send what you store to the configured LLM and embedder for extraction
3. Don't rely on `delete()` to erase a fact. The raw conversation, `history.db` and `cache.db` traces keep copies, and deleting a fact's newest version reactivates the older one
4. Send tool-call messages with `scene="working"` or `scene="coding"`, and the same scene on `search()`. Without tool messages a write falls back to chat memory
5. Keep `python -m hy_memory.server` on 127.0.0.1. It has no authentication and allows any web origin

### 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

## Questions

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

past.dev scores 63.8 (B) on agent readiness against Hy Memory's 57.7 (C), and leads in 4 of 7 scored categories. Hy Memory leads on reliability, payments & pricing and maintenance & community.

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

No hosted endpoint is listed for Hy Memory. past.dev has a hosted endpoint at https://api.past.dev.

### Are Hy Memory and past.dev open source?

Hy Memory is open source (Apache-2.0 (PyPI metadata for the 1.x releases and 2.0.1 says MIT; 2.0.2 carries Apache-2.0)). No open-source release is listed for past.dev.


## For agents

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

## Other comparisons with Hy Memory or past.dev

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

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