Function handler

app/tools/render-table.tsx:100–135

({ title, columns, rows }, { thread })

    Math.max(
      (header[c] ?? "").length,
      ...body.map((row) => (row[c] ?? "").length),
    ),
  );
  const fmt = (row: string[]) =>
    "| " +
    cols
      .map((col, c) => {
        const cell = row[c] ?? "";
        const width = widths[c] ?? 0;
        if (col.align === "right") return cell.padStart(width);
        if (col.align === "center") {
          const total = Math.max(width - cell.length, 0);
          const left = Math.floor(total / 2);
          const right = total - left;
          return " ".repeat(left) + cell + " ".repeat(right);
        }
        return cell.padEnd(width);
      })
      .join(" | ") +
    " |";
  return "```\n" + [fmt(header), ...body.map(fmt)].join("\n") + "\n```";
}

export const renderTableTool = defineChannelTool({
  name: "render_table",
  description:
    "Render tabular data as a table posted to the conversation thread. Pass " +
    "columns (each with a header and optional alignment) and rows (arrays of " +
    "cell values in column order). Use for 'show as a table' — issue lists " +
    "with several fields, metrics from a CSV, comparisons — when a chart " +
    "isn't the right shape. Max 20 columns and 99 rows.",
  parameters: schema,
  async handler({ title, columns, rows }, { thread }) {
    const { cols, dataRows, notes } = clamp(columns, rows);
    // When rows/columns were truncated, surface it both to the user (a
    // trailing <Context> note under the table) and to the agent (appended to
    // the returned status string), so a silent drop never happens.
    const noteBlock = notes.length > 0 ? <Context>{notes.join("; ")}</Context> : null;
    const noteSuffix = notes.length > 0 ? ` (${notes.join("; ")})` : "";