# `Sake.Context`
[🔗](https://github.com/hattoriai/sake/blob/v0.4.3/lib/sake/context.ex#L1)

What a component learns about the request it serves.

`scope` is the host's principal (the current user, organization, or
anything the host puts there); `token` and `scopes` are set when the
endpoint has authorization; `inputs` holds the client's answers
(elicitation, sampling, roots) on a retry; `progress` reports progress
to the client when it asked for it; `task` is the task ID when the
component runs as a task (see `Sake.Tasks`); `assigns` holds what the
server's middleware decided for this request (see `Sake.Middleware`).

`base_url` is the URL of the MCP endpoint the request reached, as the
client reaches it: scheme, host, the port when it is not the scheme's
default, and the endpoint's path, without a query or a trailing slash
(`"https://example.com/acme/mcp"`). A tool builds absolute URLs to its
own host from it, such as a link the person opens or a one-time upload
URL:

    def execute(%{name: name}, ctx) do
      uri = URI.parse(ctx.base_url)
      token = MyApp.Uploads.grant(ctx.scope, name)
      {:ok, %{upload_url: URI.to_string(%{uri | path: "/uploads/" <> token})}}
    end

`Sake.Plug` sets it from the request; on an endpoint with `auth: true`
its origin is the issuer's, as for the token's audience, and on an
external authorization server with `url:`, that `url:`'s (see
`Sake.Auth.External`). Behind a proxy that does not rewrite the
request, put `Plug.RewriteOn` before the endpoint (see "Behind a proxy"
in the security guide). It is `nil` where there is no HTTP request:
over stdio (`Sake.Stdio`) and in `Sake.Test`'s in-memory client unless
the test passes `base_url:`, so a tool that needs it should say so when
it is missing.

# `t`

```elixir
@type t() :: %Sake.Context{
  assigns: term(),
  base_url: term(),
  client_capabilities: term(),
  client_info: term(),
  conn_assigns: term(),
  era: term(),
  inputs: term(),
  log_level: term(),
  method: term(),
  progress: term(),
  protocol_version: term(),
  request_id: term(),
  reraise: term(),
  scope: term(),
  scopes: term(),
  secret: term(),
  server: term(),
  task: term(),
  token: term(),
  trace: term(),
  transport: term()
}
```

# `new`

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

---

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