Capabilities index

Deny-by-default: declare with require capability("scope"). See Capabilities & intent for the model.

capabilities.syn

-- Doc example: deny-by-default capabilities + faithful scope.
-- Uses `secret` because it proves the model with no network/disk side effects.
intent: "doc example: capabilities and intent"
require secret("APP_*")          -- name-prefix scope: covers APP_KEY, APP_DB, ... only

task read_app_key()
    -- APP_KEY is under the declared APP_* scope → allowed (still redacted, as always)
    give text(secret("APP_KEY", "demo")) == "secret(APP_KEY)"

task read_unscoped()
    -- DB_PASSWORD is NOT under APP_* → denied at the capability check (before any use)
    give secret("DB_PASSWORD")

print("APP_KEY is in scope → " + text(read_app_key()))

test "a capability you declared (in scope) is allowed"
    assert(read_app_key())

test "anything outside the declared scope is denied (deny-by-default)"
    assert_error(read_unscoped)

Capability	Gates	Scope	Auto-granted in `run`?
`stdout`	`print` / output	—	yes
`time`	`now`, `format_time`, `sleep`	—	yes
`llm`	`reason`/`decide`/`analyze`/`generate`, `llm_step` (incl. provider egress)	—	yes
`random`	`random`, `random_int`	—	no (tokens/nonces)
`net`	`http*`, `fetch`	host: `net("api.x")`, `net(".x")`, `net("``")`	no
`file`	read and write	path: `file("/data/*")`	no
`file.read` / `file.write`	least-privilege I/O	path glob	no
`db`	`sql`/`mongo_`/`redis_`	path (SQLite) or canonical URL	no
`secret`	`secret(...)`	name: `secret("APP_*")`	no
`reveal`	`reveal(...)`	name/label (scoped)	no
`exec`	`run` (shell)	command name	no
`serve`	`serve on N`	port	no (and required)
`env`	`env(...)`	name / prefix	no
`stdin`	`read_line`, free-text `ask`	—	no

Notes: path scopes are faithful (.. escapes denied). sandbox strips everything. A per-task require narrows a task to only what it declares (∩ the program). Under serve/secure mode, even the auto-granted ones must be declared.