spix_billing_credits

Instructions

Implementation Reference

• src/spix_mcp/registry.py:626-634 (registration)

  Registration of the 'billing.credits' command schema in the COMMAND_REGISTRY, which maps to MCP tool name 'spix_billing_credits'. It's a GET request to /billing/credits with 'safe' profile.

  CommandSchema(
      path="billing.credits",
      cli_usage="spix billing credits",
      http_method="GET",
      api_endpoint="/billing/credits",
      mcp_expose="tool",
      mcp_profile="safe",
      description="Show credit balance",
  ),

• src/spix_mcp/tools.py:94-203 (handler)

  Generic tool handler 'create_tool_handler' that dispatches tool calls. When 'spix_billing_credits' is called, it looks up the billing.credits schema, validates session scope, builds the endpoint URL /billing/credits, and makes a GET request to the backend API.

  async def create_tool_handler(
      session: McpSessionContext,
      tool_name: str,
      arguments: dict,
  ) -> list:
      """Execute an MCP tool call by dispatching to the backend API.
  
      This function:
      1. Resolves the tool name to a command schema
      2. Validates session scope (playbook access, channel access)
      3. Builds the API request
      4. Dispatches to the backend
      5. Returns the response as MCP TextContent
  
      Args:
          session: The MCP session context for scope validation.
          tool_name: The MCP tool name (e.g., "spix_playbook_create").
          arguments: The tool arguments from the MCP client.
  
      Returns:
          List containing a single TextContent with the JSON response.
      """
      # Import here to avoid circular imports and handle missing mcp package
      try:
          from mcp.types import TextContent
      except ImportError:
          # Fallback for when mcp is not installed
          class TextContent:  # type: ignore[no-redef]
              def __init__(self, type: str, text: str) -> None:
                  self.type = type
                  self.text = text
  
      # Resolve tool name to schema
      schema = get_schema_by_tool_name(tool_name)
      if not schema:
          return [
              TextContent(
                  type="text",
                  text=orjson.dumps(
                      {"ok": False, "error": {"code": "unknown_tool", "message": f"Unknown tool: {tool_name}"}}
                  ).decode(),
              )
          ]
  
      # Validate tool access (not disabled)
      try:
          session.validate_tool_access(schema.path)
      except Exception as e:
          from spix_mcp.session import McpScopeError
  
          if isinstance(e, McpScopeError):
              return [TextContent(type="text", text=orjson.dumps({"ok": False, "error": e.to_dict()}).decode())]
          raise
  
      # Validate channel access if applicable
      channel = infer_channel_from_tool(schema.path)
      if channel:
          try:
              session.validate_channel_access(channel)
          except Exception as e:
              from spix_mcp.session import McpScopeError
  
              if isinstance(e, McpScopeError):
                  return [TextContent(type="text", text=orjson.dumps({"ok": False, "error": e.to_dict()}).decode())]
              raise
  
      # Handle playbook_id: validate and apply default
      playbook_id = arguments.get("playbook_id")
      try:
          effective_playbook = session.validate_playbook_access(playbook_id)
          if effective_playbook and not playbook_id:
              # Apply default playbook
              arguments["playbook_id"] = effective_playbook
      except Exception as e:
          from spix_mcp.session import McpScopeError
  
          if isinstance(e, McpScopeError):
              return [TextContent(type="text", text=orjson.dumps({"ok": False, "error": e.to_dict()}).decode())]
          raise
  
      # Build endpoint URL with path parameters
      endpoint, remaining_args = build_endpoint_url(schema, arguments)
  
      # Dispatch to backend API
      client = session.client
      method = schema.http_method.lower()
  
      if method == "get":
          response = await asyncio.to_thread(client.get, endpoint, params=remaining_args if remaining_args else None)
      elif method == "post":
          response = await asyncio.to_thread(client.post, endpoint, json=remaining_args if remaining_args else None)
      elif method == "patch":
          response = await asyncio.to_thread(client.patch, endpoint, json=remaining_args if remaining_args else None)
      elif method == "delete":
          response = await asyncio.to_thread(client.delete, endpoint, params=remaining_args if remaining_args else None)
      else:
          response = await asyncio.to_thread(client.get, endpoint)
  
      # Build response envelope
      envelope: dict = {"ok": response.ok, "meta": response.meta}
      if response.ok:
          envelope["data"] = response.data
          if response.pagination:
              envelope["pagination"] = response.pagination
          if response.warnings:
              envelope["warnings"] = response.warnings
      else:
          envelope["error"] = response.error
  
      return [TextContent(type="text", text=orjson.dumps(envelope).decode())]

• src/spix_mcp/registry.py:17-49 (schema)

  CommandSchema and CommandParam dataclasses defining the schema structure used to define the 'billing.credits' tool (no params, no positional_args).

  @dataclass
  class CommandParam:
      """Schema for a command parameter."""
  
      name: str
      type: str  # "string", "integer", "boolean", "enum", "file", "array"
      required: bool = False
      description: str = ""
      choices: list[str] = field(default_factory=list)
      default: object = None
  
  
  @dataclass
  class CommandSchema:
      """Schema for a CLI command.
  
      Each command maps to:
      - A Click command in the CLI
      - Optionally an MCP tool or resource
      """
  
      path: str  # e.g., "playbook.create", "call.show"
      cli_usage: str  # e.g., "spix playbook create"
      http_method: str  # "GET", "POST", "PATCH", "DELETE"
      api_endpoint: str  # e.g., "/playbooks", "/calls/{id}"
      params: list[CommandParam] = field(default_factory=list)
      positional_args: list[CommandParam] = field(default_factory=list)
      mcp_expose: Literal["tool", "resource", None] = None
      mcp_profile: Literal["safe", "full"] = "safe"  # "safe" = included in both profiles
      destructive: bool = False
      financial: bool = False
      description: str = ""

• src/spix_mcp/tools.py:23-50 (helper)

  Helper function 'get_schema_by_tool_name' that converts MCP tool name 'spix_billing_credits' to the registry path 'billing.credits' by stripping the 'spix_' prefix and converting underscores back to dots.

  def get_schema_by_tool_name(tool_name: str) -> CommandSchema | None:
      """Look up a CommandSchema by MCP tool name.
  
      MCP tool names follow the pattern: spix_{path with dots replaced by underscores}
      e.g., "spix_playbook_create" -> "playbook.create"
  
      Args:
          tool_name: The MCP tool name (e.g., "spix_playbook_create").
  
      Returns:
          The matching CommandSchema, or None if not found.
      """
      # Remove the spix_ prefix
      if not tool_name.startswith("spix_"):
          return None
  
      path_part = tool_name[len("spix_") :]
  
      # Convert underscores back to dots for path lookup
      # We need to handle multi-part paths like "billing_credits_history" -> "billing.credits.history"
      # Try different dot positions to find the right one
      for cmd in COMMAND_REGISTRY:
          # Convert the command path to expected tool name format
          expected_tool = cmd.path.replace(".", "_")
          if expected_tool == path_part:
              return cmd
  
      return None

• src/spix_mcp/server.py:88-97 (registration)

  MCP server registration: the billing.credits schema is converted to tool name 'spix_billing_credits' (line 90) and registered as an MCP Tool with its JSON schema derived from the registry.

  for schema in tool_schemas:
      # Convert path to tool name: playbook.create -> spix_playbook_create
      tool_name = f"spix_{schema.path.replace('.', '_')}"
      tool_defs.append(
          Tool(
              name=tool_name,
              description=schema.description or f"Spix {schema.path}",
              inputSchema=build_json_schema(schema),
          )
      )