# General FAQ

Common questions about Synapse.

## What is Synapse?

Synapse is a persistent memory API for LLM agents. It gives your AI assistant
a permanent, queryable brain that survives across sessions. Instead of
forgetting everything when the chat closes, the LLM stores and retrieves
memories via a simple HTTP API.

**Learn more:** [What is Synapse?](/docs/getting-started/what-is-synapse)

## Who is Synapse for?

- **LLM agent developers** who need persistent state
- **Power users** running local LLMs with custom agents
- **Teams** building AI assistants with shared memory
- **Automation engineers** chaining LLM calls across sessions

## Is Synapse free?

Synapse is hosted at <https://synapse.schaefer.zone> and free for personal use.
For self-hosting, see the [repo](https://gitlab.com/schaefer-services/synapse).

## How is Synapse different from ChatGPT Memory?

| Feature | ChatGPT Memory | Synapse |
|---------|---------------|---------|
| Storage | OpenAI servers | Your server |
| API access | No | Yes (REST + MCP) |
| Multi-tenant | No | Yes (minds) |
| Custom categories | No | Yes (8 categories) |
| Full-text search | Limited | FTS5 + semantic |
| Self-hostable | No | Yes |

## What LLMs work with Synapse?

Any LLM that can make HTTP calls or use MCP:

- Claude (Anthropic) — via MCP or direct API
- GPT-4 / GPT-3.5 (OpenAI) — via function calling + API
- Gemini (Google) — via function calling + API
- Llama / Mistral (local) — via custom integration
- Any LLM via the Synapse MCP server

## Do I need to host Synapse myself?

No. The hosted version at <https://synapse.schaefer.zone> is available for
public use. Self-hosting is optional (for privacy, customization, or
air-gapped environments).

## How much data can I store?

There are no hard limits on the hosted version. Typical usage:

- 100-1000 memories per mind
- 1-10 KB per memory (content field)
- Total: ~10 MB per mind

For larger scale, self-host.

## Is my data private?

Yes. Each mind is isolated (see [Multi-Tenancy](/docs/concepts/multi-tenancy)).
Other users cannot see your data. The hosting provider (Schäfer Services)
has access but does not view user data.

For maximum privacy, self-host.

## Can I export my data?

Yes. Use `GET /memory/mind-export` to export all memories as JSON. See
[Backup & Restore](/docs/guides/backup-restore).

## What happens if I lose my Mind Key?

Mind Keys are shown only once at creation. If lost:

1. Login with your email/password to get a JWT
2. Create a new mind via `POST /minds`
3. Save the new Mind Key
4. (Optional) Delete the old mind via `DELETE /minds/:id`

You cannot recover memories from a mind whose key is lost.

## Can multiple LLM agents share a mind?

Yes. All agents using the same Mind Key share that mind's data. For
coordinated multi-agent work, see [Multi-Agent Coordination](/docs/guides/multi-agent-coordination).

## Does Synapse work offline?

No, Synapse requires an internet connection to the server (either hosted or
self-hosted). For offline LLMs, run Synapse locally.

## How fast is memory search?

- FTS5 keyword search: < 10ms for 1000 memories
- Semantic search: 50-100ms for 1000 memories
- Full recall: < 50ms for 1000 memories

See [FTS5 Search](/docs/concepts/fts5-search) for details.

## Can I use Synapse without an LLM?

Yes. Synapse is a generic memory API. You can use it from any application
that benefits from persistent, searchable key-value storage with categories
and tags.

## Next Steps

- [What is Synapse?](/docs/getting-started/what-is-synapse)
- [Quick Start](/docs/getting-started/quick-start)
- [API FAQ](/docs/faq/api-faq)