Sema

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Key-Value Store ​

Sema includes a persistent, JSON-backed key-value store for storing structured data across sessions. Data is automatically flushed to disk on every write.

TIP

kv/open, kv/set, and kv/delete require filesystem write capabilities (they are gated by FS_WRITE).

Functions ​

kv/open ​

Open (or create) a named KV store backed by a JSON file. If the file exists, its contents are loaded.

scheme
(kv/open "config" "/path/to/config.json")

kv/get ​

Get a value by key. Returns nil if the key doesn't exist.

scheme
(kv/get "config" "api-key")  ; => "sk-..." or nil

kv/set ​

Set a key-value pair. Values are serialized as JSON (strings, numbers, booleans, lists, maps are all supported). Returns the value.

scheme
(kv/set "config" "api-key" "sk-...")
(kv/set "config" "retries" 3)
(kv/set "config" "tags" '("a" "b" "c"))

kv/delete ​

Delete a key. Returns #t if the key existed, #f otherwise.

scheme
(kv/delete "config" "api-key")  ; => #t

kv/keys ​

List all keys in the store.

scheme
(kv/keys "config")  ; => ("api-key" "retries" "tags")

kv/close ​

Close a store, flushing any pending data.

scheme
(kv/close "config")

Example ​

scheme
;; Create a persistent store for caching API results
(kv/open "cache" "api-cache.json")

;; Store some data
(kv/set "cache" "user:123" {:name "Alice" :email "alice@example.com"})
(kv/set "cache" "user:456" {:name "Bob" :email "bob@example.com"})

;; Retrieve it
(kv/get "cache" "user:123")
; => {:email "alice@example.com" :name "Alice"}

;; List keys
(kv/keys "cache")
; => ("user:123" "user:456")

;; Clean up
(kv/delete "cache" "user:123")
(kv/close "cache")