> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getpostern.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Frequently asked questions

> What Postern is, where your data lives, what an agent can reach, and what ships today.

## What Postern is

### Is Postern an AI agent?

No. Postern has no model inside it. Your agents decide what to do. Postern checks who
they are, holds your data, answers with the slice they asked for, and records the
request.

[Some reads you make yourself in the Console deliberately get no row.](/reference/audit-log#what-does-not-get-a-row)

### Is Postern open source?

Yes — Apache-2.0, and it's the complete gateway: every connector, reads and actions,
MCP and REST access, the Console, permissions and audit. You can build on it and ship
what you build on any terms you like. Nothing here is a crippled tier: the open core is
the product, not a demo of it.

Apache rather than a copyleft licence for one reason: a connector or an agent written
against this gateway should be publishable by anyone, on any terms they like, including
inside a closed product.

## Your data

### Where does my data live?

On hardware you own: a local database, beside an encrypted vault that holds your source
passwords.

Mail is the exception. Postern stores who sent it, the subject, the dates and the
preview line. It never stores the message text. It fetches a message from the source
when an agent asks for it.

You can [export everything as JSON, or erase everything](/operate/backup-and-export),
at any time.

### Does Postern give agents my source passwords?

Never. Each agent gets its own key, and Postern keeps only a scrambled copy of that
key.
[What the vault does and does not cover](/reference/vault)

<h3 id="one-machine-target">
  Isn't one machine with everything on it a bigger target?
</h3>

You already have that exposure, spread out. Every agent holds its own copy of your
source passwords, plus whatever you pasted in. Postern puts that in one place built
for the job.
[What Postern encrypts, what it does not, and where the trust boundary sits](/reference/security-model#the-trust-boundary)

## Agents, keys and grants

### Can I use it with any agent?

Any agent that speaks MCP. On the same machine it sends its agent key on every call.
Hosted agents like claude.ai and ChatGPT sign in to Postern itself and hold a token
that rotates.

Every read is also on a REST API, for tools that do not speak MCP. To act on a source,
an agent must use MCP.
[The REST mirror carries reads only.](/reference/mcp-primitives#the-rest-read-mirror)

### Does an agent receive my entire life?

No. A new key can reach nothing until you tick a sector. Inside one it asks for what it
needs: named records, named fields, a date range, or a total. It never gets a dump.

### What happens when I revoke an agent?

Click **Agents & keys**, the agent, **Revoke**, then **Revoke the key**. Postern
refuses the key at once and cuts any session the agent still holds. Nothing upstream
changes, and you never have to change a source password.
[Revoking, rotating, and removing](/reference/agent-keys#revoking-rotating-and-removing)

## What ships, and what comes later

### What ships today?

Nine connectors across all six sectors — eight sources to connect, because Gmail and
the rest of Google connect separately.

* **Finance** — [SimpleFIN](/connect/simplefin), [Plaid](/connect/plaid)
* **Mail, calendar and contacts** — [Google and Gmail](/connect/google), [Microsoft](/connect/microsoft), [iCloud](/connect/icloud)
* **Health** — [Apple Health](/connect/apple-health), [WHOOP](/connect/whoop)
* **Home** — [Home Assistant](/connect/home-assistant)

Postern reads from all eight. Home Assistant is the only one an agent can act on; the
other seven have no actions today.

Also shipped:

* MCP for any agent, and a REST copy of every read
* the Console
* per-agent grants
* the record
* a live fetch from a source
* the vault

### What comes later?

Shared access between people, memory you own, connectors other people write, and
specialist agents that charge for their craft. All are on
[the roadmap](https://getpostern.com/#roadmap). None is in the beta.

### What will cost money?

Nothing you need to run Postern yourself: the open core stays free forever. Paid tiers
add memory you own, shared access over a hosted relay, a managed OAuth broker, and a
hosted Postern we run for you. Prices come after the beta.

## Next

<Card title="Install Postern" href="/start/install">
  Docker and a terminal · about 10 minutes · no cloud account
</Card>