@spec cancelled_notification(integer() | String.t(), String.t() | nil) :: map()

Builds a cancellation notification.

Sent to cancel a pending request.

Parameters

• request_id - ID of the request to cancel
• reason - Optional cancellation reason

Examples

msg = Hermolaos.Protocol.Messages.cancelled_notification(123)
msg = Hermolaos.Protocol.Messages.cancelled_notification(123, "User cancelled")

@spec completion_complete(map(), map()) :: map()

Builds a completion/complete request.

Requests argument completion suggestions.

Parameters

• ref - Reference object (prompt or resource)
• argument - Argument to complete

Examples

msg = Hermolaos.Protocol.Messages.completion_complete(
  %{"type" => "ref/prompt", "name" => "code_review"},
  %{"name" => "language", "value" => "eli"}
)

@spec default_protocol_version() :: String.t()

Returns the default MCP protocol version.

@spec initialize(String.t(), map(), map()) :: map()

Builds an initialize request message.

This is the first message sent by the client to establish the connection and negotiate capabilities.

Parameters

• protocol_version - The protocol version to request
• capabilities - Client capabilities map
• client_info - Client identification info

Examples

msg = Hermolaos.Protocol.Messages.initialize(
  "2025-03-26",
  %{roots: %{listChanged: true}},
  %{name: "MyClient", version: "1.0.0"}
)

@spec initialized_notification() :: map()

Builds the initialized notification.

Sent by the client after receiving a successful initialize response to indicate the handshake is complete.

Examples

msg = Hermolaos.Protocol.Messages.initialized_notification()
# => %{"method" => "notifications/initialized"}

@spec logging_set_level(String.t()) :: map()

Builds a logging/setLevel request.

Sets the server's logging level.

Parameters

• level - Log level (debug, info, notice, warning, error, critical, alert, emergency)

Examples

msg = Hermolaos.Protocol.Messages.logging_set_level("debug")

@spec ping() :: map()

Builds a ping request.

Used to check if the connection is alive.

Examples

msg = Hermolaos.Protocol.Messages.ping()
# => %{"method" => "ping"}

@spec ping_response() :: map()

Builds a response to a ping request.

@spec progress_notification(String.t() | integer(), number(), number() | nil) :: map()

Builds a progress notification.

Sent to report progress on a long-running operation.

Parameters

• progress_token - Token identifying the operation
• progress - Current progress value
• total - Optional total value

Examples

msg = Hermolaos.Protocol.Messages.progress_notification("op123", 50, 100)

@spec prompts_get(String.t(), map()) :: map()

Builds a prompts/get request.

Gets a specific prompt, optionally with argument values.

Parameters

• name - Prompt name
• arguments - Optional argument values

Examples

msg = Hermolaos.Protocol.Messages.prompts_get("code_review")
msg = Hermolaos.Protocol.Messages.prompts_get("summarize", %{"language" => "elixir"})

@spec prompts_list(String.t() | nil) :: map()

Builds a prompts/list request.

Lists all prompts available on the server.

Parameters

• cursor - Optional pagination cursor

Examples

msg = Hermolaos.Protocol.Messages.prompts_list()

@spec resources_list(String.t() | nil) :: map()

Builds a resources/list request.

Lists all resources available on the server.

Parameters

• cursor - Optional pagination cursor

Examples

msg = Hermolaos.Protocol.Messages.resources_list()

@spec resources_read(String.t()) :: map()

Builds a resources/read request.

Reads the content of a specific resource.

Parameters

• uri - Resource URI

Examples

msg = Hermolaos.Protocol.Messages.resources_read("file:///project/README.md")

@spec resources_subscribe(String.t()) :: map()

Builds a resources/subscribe request.

Subscribes to updates for a specific resource.

Parameters

• uri - Resource URI

Examples

msg = Hermolaos.Protocol.Messages.resources_subscribe("file:///project/src/main.rs")

@spec resources_templates_list(String.t() | nil) :: map()

Builds a resources/templates/list request.

Lists resource templates available on the server.

Parameters

• cursor - Optional pagination cursor

@spec resources_unsubscribe(String.t()) :: map()

Builds a resources/unsubscribe request.

Unsubscribes from updates for a specific resource.

Parameters

• uri - Resource URI

@spec roots_list_changed_notification() :: map()

Builds a roots/list_changed notification.

Sent when the client's root list changes.

@spec roots_list_response([map()]) :: map()

Builds a response to a roots/list request.

Parameters

• roots - List of root objects

Examples

msg = Hermolaos.Protocol.Messages.roots_list_response([
  %{"uri" => "file:///project", "name" => "Project Root"}
])

@spec sampling_not_supported_error() :: map()

Builds an error response to a sampling/createMessage request.

Used when the client doesn't support sampling.

@spec tools_call(String.t(), map()) :: map()

Builds a tools/call request.

Invokes a tool with the given arguments.

Parameters

• name - Tool name
• arguments - Tool arguments map

Examples

msg = Hermolaos.Protocol.Messages.tools_call("read_file", %{"path" => "/tmp/test.txt"})

@spec tools_list(String.t() | nil) :: map()

Builds a tools/list request.

Lists all tools available on the server.

Parameters

• cursor - Optional pagination cursor

Examples

msg = Hermolaos.Protocol.Messages.tools_list()
msg = Hermolaos.Protocol.Messages.tools_list("cursor123")