# `Snodo.Server.Runtime`
[🔗](https://github.com/joshrotenberg/snodo/blob/v0.1.0/lib/snodo/server/runtime.ex#L1)

Immutable server configuration shared by direct and transport dispatch.

# `cache_policy`

```elixir
@type cache_policy() :: %{ttl_ms: non_neg_integer(), scope: String.t()}
```

# `t`

```elixir
@type t() :: %Snodo.Server.Runtime{
  authorization: Snodo.Authorization.config(),
  capabilities: map(),
  discovery_cache: cache_policy(),
  extension_registry: Snodo.Extension.Registry.t(),
  instructions: String.t() | nil,
  instrumentation: Snodo.Instrumentation.Config.t() | nil,
  pagination: Snodo.Pagination.t(),
  prompts_cache: cache_policy(),
  protocol_registry: Snodo.Protocol.Registry.t(),
  resources_cache: cache_policy(),
  router: Snodo.Router.t(),
  schema_validator: module(),
  server_info: map(),
  subscription_source: Snodo.Subscription.Source.Config.t() | nil,
  tools_cache: cache_policy()
}
```

# `new`

```elixir
@spec new(keyword()) :: t()
```

Builds and validates a runtime. It starts no process.

A module that uses `Snodo.Server` builds its runtime with `runtime/1`, which
calls this function with the declared options and any overrides.

Required options:

  * `:router` - the `Snodo.Router` with the registered components.
  * `:protocols` - the protocol dialect modules to enable, in preference
    order, such as `[Snodo.Protocol.V2026_07_28]`.
  * `:server_info` - a map with string `"name"` and `"version"` and,
    optionally, `"title"`, `"description"`, `"websiteUrl"`, and `"icons"`.

Other options:

  * `:capabilities` - the server capabilities map. Defaults to `"tools"`,
    `"prompts"`, and `"resources"` for each kind the router has
    registered, plus `"completions"` when a registered prompt or resource
    template supports completion.
  * `:extensions` - `Snodo.Extension` modules or `{module, options}`
    tuples. Defaults to `[]`.
  * `:instructions` - a string returned in `server/discover` and
    `initialize` results, or `nil` (the default).
  * `:schema_validator` - a `Snodo.Schema.Validator` module. Defaults to
    `Snodo.Schema.Validator.Passthrough`.
  * `:subscription_source` - a `Snodo.Subscription.Source` module or
    `{module, options}`. Defaults to `nil`, which leaves
    `subscriptions/listen` unavailable.
  * `:instrumentation` - a `Snodo.Instrumentation` sink module or
    `{module, options}`. Defaults to `nil`.
  * `:authorization` - a `Snodo.Authorization` policy module or
    `{module, options}`. Defaults to `nil`.
  * `:discovery_cache`, `:tools_cache`, `:prompts_cache`,
    `:resources_cache` - `[ttl_ms: non_neg_integer, scope: "private" |
    "public"]`. Each defaults to `ttl_ms: 0, scope: "private"`.
  * `:pagination` - `[page_size: pos_integer]`. Defaults to a page size
    of 100.

A missing required option raises `KeyError`. An invalid value raises
`ArgumentError`, including a capability an enabled protocol profile does
not support, `"completions"` without a completion-capable component, a
`listChanged` or `subscribe` setting of `true` without a
`:subscription_source`, and an advertised extension that is not installed.
When an initialize-era dialect is enabled, a warning is logged naming any
tool those clients cannot list.

---

*Consult [api-reference.md](api-reference.md) for complete listing*