Fermat MCP

Instructions

Implementation Reference

• fmcp/mpl_mcp/core/stem_chart.py:8-136 (handler)

  The main handler function `plot_stem` that generates stem plots using matplotlib's stem function, supports multiple series, vertical/horizontal orientation, and returns a PNG image.
  def plot_stem( x_data: Union[List[Union[float, int]], List[List[Union[float, int]]]], y_data: Union[List[Union[float, int]], List[List[Union[float, int]]]], labels: Optional[Union[str, List[str]]] = None, title: str = "", xlabel: str = "", ylabel: str = "", colors: Union[str, List[str]] = "blue", linefmt: str = "-", markerfmt: str = "o", basefmt: str = "k-", bottom: float = 0.0, orientation: str = "vertical", # "vertical" or "horizontal" dpi: int = 200, figsize: Optional[List[Union[int, float]]] = None, grid: bool = True, legend: bool = False, ) -> Image: """ Create a stem plot (vertical or horizontal) with customizable appearance. Args: x_data: X-axis data points (1D array-like) y_data: Y-axis data points (1D or 2D array-like for multiple series) labels: Label or list of labels for the data series title: Plot title xlabel: Label for the x-axis ylabel: Label for the y-axis colors: Color or list of colors for the stems and markers linefmt: Line style for the stems (default: "-" for solid line) markerfmt: Marker style for the points (default: "o" for circles) basefmt: Format of the baseline (default: "k-" for black line) bottom: Position of the baseline (default: 0.0) orientation: "vertical" or "horizontal" (default: "vertical") dpi: Output image resolution (dots per inch, default: 200) figsize: Figure size as (width, height) in inches. grid: Whether to show grid lines (default: True) legend: Whether to show legend (default: False) Returns: FastMCP Image object with the plotted stem chart """ # Convert inputs to numpy arrays with explicit float type x = np.asarray(x_data, dtype=float) y = np.asarray(y_data, dtype=float) # Handle 1D y_data case by adding an extra dimension if y.ndim == 1: y = y.reshape(1, -1) # Ensure x matches the number of data points in y if x.ndim == 1 and len(x) != y.shape[1]: x = np.tile(x, (y.shape[0], 1)) # Handle labels — normalize to a list if labels is None: labels_list: List[str] = [""] * y.shape[0] elif isinstance(labels, str): labels_list = [labels] else: labels_list = list(labels) # Handle colors — normalize to a list if isinstance(colors, str): colors_list = [colors] * y.shape[0] else: colors_list = list(colors) # Create figure with specified size using OO interface # Normalize figsize if figsize and len(figsize) >= 2: figsize_vals = (float(figsize[0]), float(figsize[1])) else: figsize_vals = (6.0, 4.0) fig, ax = plt.subplots(figsize=figsize_vals, dpi=dpi) # Create the stem plot for each series # Create the stem plot for each series for i in range(y.shape[0]): current_label = labels_list[i] if i < len(labels_list) else f"Series {i+1}" current_color = colors_list[i % len(colors_list)] # Create the stem plot if orientation == "vertical": markerline, stemlines, baseline = ax.stem( x[i] if x.ndim > 1 else x, y[i], linefmt=linefmt, markerfmt=markerfmt, basefmt=basefmt, bottom=bottom, label=current_label, ) else: # horizontal markerline, stemlines, baseline = ax.stem( y[i], x[i] if x.ndim > 1 else x, linefmt=linefmt, markerfmt=markerfmt, basefmt=basefmt, bottom=bottom, label=current_label, orientation="horizontal", ) # Set the color for this series plt.setp(stemlines, "color", current_color) plt.setp(markerline, "color", current_color) plt.setp(baseline, "color", "black") # Customize the plot ax.set_title(title) ax.set_xlabel(xlabel if orientation == "vertical" else ylabel) ax.set_ylabel(ylabel if orientation == "vertical" else xlabel) if grid: ax.grid(True, linestyle="--", alpha=0.7) if legend and any(labels_list): ax.legend() # Save the plot to a buffer and close the figure buf = io.BytesIO() fig.savefig(buf, format="png", dpi=dpi, bbox_inches="tight") plt.close(fig) buf.seek(0) return Image(data=buf.read(), format="png")
• fmcp/mpl_mcp/server.py:22-22 (registration)

  Registers the `plot_stem` function as an MCP tool under the name `mpl_mcp_plot_stem` using FastMCP's tool decorator.
  mpl_mcp.tool(plot_stem, description="Plots stem chart of given datavalues")
• fmcp/mpl_mcp/core/stem_chart.py:8-25 (schema)

  The function signature with type annotations defines the input schema and output type for the tool.
  def plot_stem( x_data: Union[List[Union[float, int]], List[List[Union[float, int]]]], y_data: Union[List[Union[float, int]], List[List[Union[float, int]]]], labels: Optional[Union[str, List[str]]] = None, title: str = "", xlabel: str = "", ylabel: str = "", colors: Union[str, List[str]] = "blue", linefmt: str = "-", markerfmt: str = "o", basefmt: str = "k-", bottom: float = 0.0, orientation: str = "vertical", # "vertical" or "horizontal" dpi: int = 200, figsize: Optional[List[Union[int, float]]] = None, grid: bool = True, legend: bool = False, ) -> Image: