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Import & Export

The supervisor exposes two endpoints to facilitate data transfer between stores:

  • POST /import: Takes JSON frame data and imports it as-is, preserving frame id and content hash
  • POST /cas: Stores posted content in CAS and returns its hash

Commands

xs.nu provides two commands to utilize these endpoints:

Terminal window
# Export store at $env.XS_ADDR to path
.export <path>


# Import dump at path to $env.XS_ADDR
.import <path>

The exported data includes:

  • Frame metadata in frames.jsonl
  • Content files in cas/ directory

These xs.nu commands operate on a whole export directory.

From eval and handlers

Inside xs eval and handler scripts (actions, actors, services) two builtins expose the import primitives directly:

  • .import inserts a single frame verbatim, preserving its id. It is the in-engine equivalent of the xs import CLI and the POST /import endpoint, and the primitive the directory-level .import <path> helper is built on.
  • .cas-post writes the pipeline input to the CAS and returns its hash, the write counterpart to .cas and the in-engine equivalent of POST /cas.
Terminal window
# pipe in a frame record (or its JSON) to restore it
$frame | .import


# stash content in the CAS, keep the hash to reference from a frame
let hash = ("some content" | .cas-post)

Version Compatibility

Version 0.1.0 was the first version supporting imports, though the 0.1.0 client can export data from 0.0.9 stores.

Example

Terminal window
# Export from remote store
with-env {XS_ADDR: "https://user:token@remote-store.example.com"} {
    .export backup
}


# Import to local store
with-env {XS_ADDR: "./store"} {
    .import backup
}