Core concepts
Private memory
How an API key gives your assistant a private, isolated memory namespace on Pastepile, and how scopes decide what search and list can see.
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The core idea of the Pastepile MCP server is durable, URL-addressable memory: an assistant saves knowledge during one session and retrieves it in any later session, on any machine, from any client.
The per-key namespace
Every paste saved with an API key joins that key's private namespace. `pastepile_search` and `pastepile_list` then default to scope mine, which covers exactly that namespace: titles, filenames, and file contents, including unlisted pastes no public query can see.
- Isolation is by key hash on the server. One key can never list, search, or enumerate another key's pastes.
- Scope
publicremains one argument away, so the public corpus is never out of reach. - Without a key there is no
mine: search and list operate on the public corpus only.
Visibility vs scope
Two independent axes that are easy to conflate:
| Axis | Values | Controls |
|---|---|---|
visibility (set at save time) | unlisted (default), public | Whether a paste appears in public listings and search |
scope (set at query time) | mine, public | Which corpus search and list read from |
An unlisted paste saved with your key is invisible to the world but fully visible to scope: "mine". That combination, unlisted plus mine, is what makes the namespace feel like memory instead of publishing.
Durability
Saves default to expiry: "never" so memory persists. On a free key the default falls back to 1mo and the result says so in expiry_note; Pro keys keep never. The full policy, including what happens when you pass an explicit never on a free key, is on the Limits page.
Patterns that work
- Give pastes descriptive titles; titles are the strongest search signal.
- Adopt title prefixes per project (
api:,infra:) so scoped searches stay precise as memory grows. - Save durable artifacts (decisions, designs, runbooks), not transient chatter.
- Prefer one save holding several files' worth of context over many fragment saves.