access: values sealed for their readers

cs1.<age file>: a value encrypted with age to its readers' SSH keys,
which no node decrypts. _continuum/access/sealed declares paths whose
values must be sealed, for named readers or anyone; nodes check the
recipients by age's key tags, at the API and on receipt.

Auth plan M8, reworked: sealed values instead of containers, readers
as users only (nodes hold no keys).

1 files changed, 8 insertions, 0 deletions

diff --git a/docs/api.md b/docs/api.md
index 92289bf..7d7a563 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -302,6 +302,14 @@ and a read of one names its signer (`x-continuum-signed-by`). `?raw=true` shows
 they are stored, envelopes, which anyone can check; so do typed JSON and native reads,
 and streams (`/stream`).
 
+## Sealed values
+
+A value may be sealed for its readers, encrypted with age to their SSH keys
+([`access.md`](access.md), Values sealed for their readers): a string,
+`cs1.<age file>`, that the API stores and shows as it is. Where the swarm declares
+values sealed, a write leaving one there plain, or sealed for others than the declared
+readers' keys, is `409`.
+
 ## Protocol data
 
 `_continuum` holds what the nodes coordinate through: the swarm ID, the member registry,