@spec compatible_transports(version(), [module()]) :: [module()]

Returns transport modules that support a protocol version.

Parameters

• version - The protocol version
• transport_modules - List of transport modules to check

Examples

iex> transports = [Hermes.Transport.STDIO, Hermes.Transport.SSE]
iex> Hermes.Protocol.compatible_transports("2024-11-05", transports)
[Hermes.Transport.STDIO, Hermes.Transport.SSE]

@spec fallback_version() :: version()

Returns the fallback protocol version for compatibility.

Examples

iex> Hermes.Protocol.fallback_version()
"2024-11-05"

@spec get_features(version()) :: MapSet.t(feature())

Returns the set of features supported by a protocol version.

Parameters

• version - The protocol version

Examples

iex> features = Hermes.Protocol.get_features("2025-03-26")
iex> MapSet.member?(features, :json_rpc_batching)
true

@spec latest_version() :: version()

Returns the latest supported protocol version.

Examples

iex> Hermes.Protocol.latest_version()
"2025-03-26"

@spec negotiate_version(version(), version()) ::
  {:ok, version()} | {:error, Hermes.MCP.Error.t()}

Negotiates protocol version between client and server versions.

Returns the best compatible version or an error if incompatible.

Parameters

• client_version - The client's preferred protocol version
• server_version - The server's supported protocol version

Examples

iex> Hermes.Protocol.negotiate_version("2025-03-26", "2025-03-26")
{:ok, "2025-03-26"}

iex> Hermes.Protocol.negotiate_version("2025-03-26", "2024-11-05")
{:ok, "2024-11-05"}

iex> Hermes.Protocol.negotiate_version("2024-11-05", "1.0.0")
{:error, %Hermes.MCP.Error{reason: :incompatible_versions}}

@spec supported_versions() :: [version()]

Returns all supported protocol versions.

Examples

iex> Hermes.Protocol.supported_versions()
["2024-11-05", "2025-03-26"]

@spec supports_feature?(version(), feature()) :: boolean()

Checks if a feature is supported by a protocol version.

Parameters

• version - The protocol version
• feature - The feature to check

Examples

iex> Hermes.Protocol.supports_feature?("2025-03-26", :json_rpc_batching)
true

iex> Hermes.Protocol.supports_feature?("2024-11-05", :authorization)
false

@spec validate_client_config(version(), module(), map()) ::
  :ok | {:error, Hermes.MCP.Error.t()}

Validates client configuration for protocol compatibility.

This function checks if the client configuration is compatible with the specified protocol version, including transport and capabilities.

Parameters

• version - The protocol version
• transport_module - The transport module being used
• capabilities - The client capabilities

Examples

iex> capabilities = %{"resources" => %{}, "tools" => %{}}
iex> Hermes.Protocol.validate_client_config("2024-11-05", Hermes.Transport.SSE, capabilities)
:ok

@spec validate_transport(version(), module()) :: :ok | {:error, Hermes.MCP.Error.t()}

Validates if a transport is compatible with a protocol version.

Parameters

• version - The protocol version
• transport_module - The transport module to validate

Examples

iex> Hermes.Protocol.validate_transport("2024-11-05", Hermes.Transport.SSE)
:ok

iex> Hermes.Protocol.validate_transport("2024-11-05", Hermes.Transport.StreamableHTTP)
{:error, %Hermes.MCP.Error{reason: :incompatible_transport}}

@spec validate_version(version()) :: :ok | {:error, Hermes.MCP.Error.t()}

Validates if a protocol version is supported.

Parameters

• version - The protocol version to validate

Examples

iex> Hermes.Protocol.validate_version("2024-11-05")
:ok

iex> Hermes.Protocol.validate_version("1.0.0")
{:error, %Hermes.MCP.Error{reason: :unsupported_protocol_version}}