XLSX Libraries Are Verbose
You need to generate an Excel file from application data. Maybe it’s a monthly report, an invoice, or a data export a client asked for. So you reach for an XLSX library.
In JavaScript, that’s ExcelJS or SheetJS. You create a workbook, add a worksheet, set column widths, iterate over rows, apply number formats using Excel format strings, set font properties on individual cells, and handle the binary output. What should be “turn this JSON into a spreadsheet” becomes 50+ lines of imperative cell manipulation.
And that’s before you need currency formatting that works across locales, or formulas that reference ranges, or merged cells for section headers. Each one adds another layer of library-specific API surface you need to learn and maintain.
A Better Approach: Describe the Spreadsheet, Get the File
The Sheet Generation API takes a JSON description of your spreadsheet and returns a formatted XLSX file. You describe what the spreadsheet should look like — columns, rows, formats, styles — and the API handles the binary format details.
Let’s build one up step by step.
Step 1: A Basic Spreadsheet
Start with the minimum: columns and rows of plain text.
Request
curl -X POST https://api.iterationlayer.com/sheet-generation/v1/generate \
-H "Authorization: Bearer $API_KEY" \
-H "Content-Type: application/json" \
-d '{
"format": "xlsx",
"sheets": [
{
"name": "Employees",
"columns": [
{
"name": "Name"
},
{
"name": "Department"
},
{
"name": "Start Date"
}
],
"rows": [
[
{
"value": "Alice Chen"
},
{
"value": "Engineering"
},
{
"value": "2024-01-15"
}
],
[
{
"value": "Bob Martinez"
},
{
"value": "Design"
},
{
"value": "2024-03-01"
}
],
[
{
"value": "Carol Tanaka"
},
{
"value": "Engineering"
},
{
"value": "2024-06-10"
}
]
]
}
]
}'Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
import { IterationLayer } from "iterationlayer";
const client = new IterationLayer({
apiKey: "YOUR_API_KEY",
});
const result = await client.generateSheet({
format: "xlsx",
sheets: [
{
name: "Employees",
columns: [
{
name: "Name",
},
{
name: "Department",
},
{
name: "Start Date",
},
],
rows: [
[
{
value: "Alice Chen",
},
{
value: "Engineering",
},
{
value: "2024-01-15",
},
],
[
{
value: "Bob Martinez",
},
{
value: "Design",
},
{
value: "2024-03-01",
},
],
[
{
value: "Carol Tanaka",
},
{
value: "Engineering",
},
{
value: "2024-06-10",
},
],
],
},
],
});Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
from iterationlayer import IterationLayer
client = IterationLayer(api_key="YOUR_API_KEY")
result = client.generate_sheet(
format="xlsx",
sheets=[
{
"name": "Employees",
"columns": [
{
"name": "Name",
},
{
"name": "Department",
},
{
"name": "Start Date",
},
],
"rows": [
[
{
"value": "Alice Chen",
},
{
"value": "Engineering",
},
{
"value": "2024-01-15",
},
],
[
{
"value": "Bob Martinez",
},
{
"value": "Design",
},
{
"value": "2024-03-01",
},
],
[
{
"value": "Carol Tanaka",
},
{
"value": "Engineering",
},
{
"value": "2024-06-10",
},
],
],
},
],
)Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
package main
import il "github.com/iterationlayer/sdk-go"
func main() {
client := il.NewClient("YOUR_API_KEY")
result, err := client.GenerateSheet(il.GenerateSheetRequest{
Format: "xlsx",
Sheets: []il.Sheet{
{
Name: "Employees",
Columns: []il.SheetColumn{
{
Name: "Name",
},
{
Name: "Department",
},
{
Name: "Start Date",
},
},
Rows: []il.SheetRow{
{
{
Value: "Alice Chen",
},
{
Value: "Engineering",
},
{
Value: "2024-01-15",
},
},
{
{
Value: "Bob Martinez",
},
{
Value: "Design",
},
{
Value: "2024-03-01",
},
},
{
{
Value: "Carol Tanaka",
},
{
Value: "Engineering",
},
{
Value: "2024-06-10",
},
},
},
},
},
})
if err != nil {
panic(err)
}
_ = result
}Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}
That’s a working XLSX file. Three columns, three rows, ready to open in Excel. The columns array defines the header row. Each row is an array of cell objects.
Step 2: Add Number Formatting
Real spreadsheets have numbers, and numbers need formatting. Let’s add salary data with currency formatting.
Request
curl -X POST https://api.iterationlayer.com/sheet-generation/v1/generate \
-H "Authorization: Bearer $API_KEY" \
-H "Content-Type: application/json" \
-d '{
"format": "xlsx",
"sheets": [
{
"name": "Compensation",
"columns": [
{
"name": "Name"
},
{
"name": "Department"
},
{
"name": "Annual Salary"
},
{
"name": "Bonus Rate"
}
],
"rows": [
[
{
"value": "Alice Chen"
},
{
"value": "Engineering"
},
{
"value": 125000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 0.15,
"format": "percentage"
}
],
[
{
"value": "Bob Martinez"
},
{
"value": "Design"
},
{
"value": 98000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 0.10,
"format": "percentage"
}
],
[
{
"value": "Carol Tanaka"
},
{
"value": "Engineering"
},
{
"value": 115000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 0.12,
"format": "percentage"
}
]
]
}
]
}'Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
import { IterationLayer } from "iterationlayer";
const client = new IterationLayer({
apiKey: "YOUR_API_KEY",
});
const result = await client.generateSheet({
format: "xlsx",
sheets: [
{
name: "Compensation",
columns: [
{
name: "Name",
},
{
name: "Department",
},
{
name: "Annual Salary",
},
{
name: "Bonus Rate",
},
],
rows: [
[
{
value: "Alice Chen",
},
{
value: "Engineering",
},
{
value: 125_000,
format: "currency",
currency_code: "USD",
},
{
value: 0.15,
format: "percentage",
},
],
[
{
value: "Bob Martinez",
},
{
value: "Design",
},
{
value: 98_000,
format: "currency",
currency_code: "USD",
},
{
value: 0.10,
format: "percentage",
},
],
[
{
value: "Carol Tanaka",
},
{
value: "Engineering",
},
{
value: 115_000,
format: "currency",
currency_code: "USD",
},
{
value: 0.12,
format: "percentage",
},
],
],
},
],
});Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
from iterationlayer import IterationLayer
client = IterationLayer(api_key="YOUR_API_KEY")
result = client.generate_sheet(
format="xlsx",
sheets=[
{
"name": "Compensation",
"columns": [
{
"name": "Name",
},
{
"name": "Department",
},
{
"name": "Annual Salary",
},
{
"name": "Bonus Rate",
},
],
"rows": [
[
{
"value": "Alice Chen",
},
{
"value": "Engineering",
},
{
"value": 125000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 0.15,
"format": "percentage",
},
],
[
{
"value": "Bob Martinez",
},
{
"value": "Design",
},
{
"value": 98000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 0.10,
"format": "percentage",
},
],
[
{
"value": "Carol Tanaka",
},
{
"value": "Engineering",
},
{
"value": 115000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 0.12,
"format": "percentage",
},
],
],
},
],
)Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
package main
import il "github.com/iterationlayer/sdk-go"
func main() {
client := il.NewClient("YOUR_API_KEY")
result, err := client.GenerateSheet(il.GenerateSheetRequest{
Format: "xlsx",
Sheets: []il.Sheet{
{
Name: "Compensation",
Columns: []il.SheetColumn{
{
Name: "Name",
},
{
Name: "Department",
},
{
Name: "Annual Salary",
},
{
Name: "Bonus Rate",
},
},
Rows: []il.SheetRow{
{
{
Value: "Alice Chen",
},
{
Value: "Engineering",
},
{
Value: 125000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 0.15,
Format: "percentage",
},
},
{
{
Value: "Bob Martinez",
},
{
Value: "Design",
},
{
Value: 98000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 0.10,
Format: "percentage",
},
},
{
{
Value: "Carol Tanaka",
},
{
Value: "Engineering",
},
{
Value: 115000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 0.12,
Format: "percentage",
},
},
},
},
},
})
if err != nil {
panic(err)
}
_ = result
}Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}
The format: "currency" field tells the API to render the value with the correct symbol and decimal places. USD gets $125,000.00. EUR would get the euro symbol. The API supports 162 ISO 4217 currency codes.
The format: "percentage" field multiplies by 100 and adds a percent sign. The value 0.15 renders as 15.00%.
For European-style number formatting, add a number_style:
{
value: 125_000,
format: "currency",
currency_code: "EUR",
number_style: "period_comma",
}
// Renders as: €125.000,00Step 3: Apply Styles
A plain spreadsheet works, but styled headers and readable fonts make the difference between “data dump” and “professional report.”
Request
curl -X POST https://api.iterationlayer.com/sheet-generation/v1/generate \
-H "Authorization: Bearer $API_KEY" \
-H "Content-Type: application/json" \
-d '{
"format": "xlsx",
"styles": {
"header": {
"is_bold": true,
"font_size_in_pt": 11,
"font_color": "#ffffff",
"background_color": "#2d3748",
"horizontal_alignment": "center"
},
"body": {
"font_size_in_pt": 10
}
},
"sheets": [
{
"name": "Compensation",
"columns": [
{
"name": "Name",
"width": 25
},
{
"name": "Department",
"width": 20
},
{
"name": "Annual Salary",
"width": 18
},
{
"name": "Bonus Rate",
"width": 15
}
],
"rows": [
[
{
"value": "Alice Chen"
},
{
"value": "Engineering"
},
{
"value": 125000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 0.15,
"format": "percentage"
}
],
[
{
"value": "Bob Martinez"
},
{
"value": "Design"
},
{
"value": 98000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 0.10,
"format": "percentage"
}
],
[
{
"value": "Carol Tanaka"
},
{
"value": "Engineering"
},
{
"value": 115000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 0.12,
"format": "percentage"
}
]
]
}
]
}'Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
import { IterationLayer } from "iterationlayer";
const client = new IterationLayer({
apiKey: "YOUR_API_KEY",
});
const result = await client.generateSheet({
format: "xlsx",
styles: {
header: {
is_bold: true,
font_size_in_pt: 11,
font_color: "#ffffff",
background_color: "#2d3748",
horizontal_alignment: "center",
},
body: {
font_size_in_pt: 10,
},
},
sheets: [
{
name: "Compensation",
columns: [
{
name: "Name",
width: 25,
},
{
name: "Department",
width: 20,
},
{
name: "Annual Salary",
width: 18,
},
{
name: "Bonus Rate",
width: 15,
},
],
rows: [
[
{
value: "Alice Chen",
},
{
value: "Engineering",
},
{
value: 125_000,
format: "currency",
currency_code: "USD",
},
{
value: 0.15,
format: "percentage",
},
],
[
{
value: "Bob Martinez",
},
{
value: "Design",
},
{
value: 98_000,
format: "currency",
currency_code: "USD",
},
{
value: 0.10,
format: "percentage",
},
],
[
{
value: "Carol Tanaka",
},
{
value: "Engineering",
},
{
value: 115_000,
format: "currency",
currency_code: "USD",
},
{
value: 0.12,
format: "percentage",
},
],
],
},
],
});Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
from iterationlayer import IterationLayer
client = IterationLayer(api_key="YOUR_API_KEY")
result = client.generate_sheet(
format="xlsx",
styles={
"header": {
"is_bold": True,
"font_size_in_pt": 11,
"font_color": "#ffffff",
"background_color": "#2d3748",
"horizontal_alignment": "center",
},
"body": {
"font_size_in_pt": 10,
},
},
sheets=[
{
"name": "Compensation",
"columns": [
{
"name": "Name",
"width": 25,
},
{
"name": "Department",
"width": 20,
},
{
"name": "Annual Salary",
"width": 18,
},
{
"name": "Bonus Rate",
"width": 15,
},
],
"rows": [
[
{
"value": "Alice Chen",
},
{
"value": "Engineering",
},
{
"value": 125000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 0.15,
"format": "percentage",
},
],
[
{
"value": "Bob Martinez",
},
{
"value": "Design",
},
{
"value": 98000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 0.10,
"format": "percentage",
},
],
[
{
"value": "Carol Tanaka",
},
{
"value": "Engineering",
},
{
"value": 115000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 0.12,
"format": "percentage",
},
],
],
},
],
)Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
package main
import il "github.com/iterationlayer/sdk-go"
func main() {
client := il.NewClient("YOUR_API_KEY")
result, err := client.GenerateSheet(il.GenerateSheetRequest{
Format: "xlsx",
Styles: &il.SheetStyles{
Header: &il.CellStyle{
IsBold: true,
FontSizeInPt: 11,
FontColor: "#ffffff",
BackgroundColor: "#2d3748",
HorizontalAlignment: "center",
},
Body: &il.CellStyle{
FontSizeInPt: 10,
},
},
Sheets: []il.Sheet{
{
Name: "Compensation",
Columns: []il.SheetColumn{
{
Name: "Name",
Width: 25,
},
{
Name: "Department",
Width: 20,
},
{
Name: "Annual Salary",
Width: 18,
},
{
Name: "Bonus Rate",
Width: 15,
},
},
Rows: []il.SheetRow{
{
{
Value: "Alice Chen",
},
{
Value: "Engineering",
},
{
Value: 125000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 0.15,
Format: "percentage",
},
},
{
{
Value: "Bob Martinez",
},
{
Value: "Design",
},
{
Value: 98000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 0.10,
Format: "percentage",
},
},
{
{
Value: "Carol Tanaka",
},
{
Value: "Engineering",
},
{
Value: 115000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 0.12,
Format: "percentage",
},
},
},
},
},
})
if err != nil {
panic(err)
}
_ = result
}Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}
The styles.header object applies to the header row. The styles.body object applies to every data row. Dark header with white text, readable font sizes, and column widths that fit the content.
You can override any style on a specific cell. Need to highlight a value in red? Add a styles field to that cell:
{
value: 98_000,
format: "currency",
currency_code: "USD",
styles: {
font_color: "#cc0000",
is_bold: true,
},
}The per-cell style merges with the body style. Only the properties you specify get overridden.
Step 4: Add Formulas
Spreadsheets should compute things. The API supports formula cells — values that start with = are treated as native Excel formulas.
Request
curl -X POST https://api.iterationlayer.com/sheet-generation/v1/generate \
-H "Authorization: Bearer $API_KEY" \
-H "Content-Type: application/json" \
-d '{
"format": "xlsx",
"styles": {
"header": {
"is_bold": true,
"background_color": "#2d3748",
"font_color": "#ffffff"
}
},
"sheets": [
{
"name": "Project Budget",
"columns": [
{
"name": "Category",
"width": 25
},
{
"name": "Q1",
"width": 15
},
{
"name": "Q2",
"width": 15
},
{
"name": "Q3",
"width": 15
},
{
"name": "Q4",
"width": 15
},
{
"name": "Annual Total",
"width": 18
}
],
"rows": [
[
{
"value": "Engineering"
},
{
"value": 45000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 48000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 52000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 50000,
"format": "currency",
"currency_code": "USD"
},
{
"value": "=SUM(B2:E2)",
"format": "currency",
"currency_code": "USD"
}
],
[
{
"value": "Design"
},
{
"value": 22000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 24000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 23000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 25000,
"format": "currency",
"currency_code": "USD"
},
{
"value": "=SUM(B3:E3)",
"format": "currency",
"currency_code": "USD"
}
],
[
{
"value": "Infrastructure"
},
{
"value": 15000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 15000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 18000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 20000,
"format": "currency",
"currency_code": "USD"
},
{
"value": "=SUM(B4:E4)",
"format": "currency",
"currency_code": "USD"
}
],
[
{
"value": "Total",
"styles": {
"is_bold": true
}
},
{
"value": "=SUM(B2:B4)",
"format": "currency",
"currency_code": "USD"
},
{
"value": "=SUM(C2:C4)",
"format": "currency",
"currency_code": "USD"
},
{
"value": "=SUM(D2:D4)",
"format": "currency",
"currency_code": "USD"
},
{
"value": "=SUM(E2:E4)",
"format": "currency",
"currency_code": "USD"
},
{
"value": "=SUM(F2:F4)",
"format": "currency",
"currency_code": "USD"
}
]
]
}
]
}'Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
import { IterationLayer } from "iterationlayer";
const client = new IterationLayer({
apiKey: "YOUR_API_KEY",
});
const result = await client.generateSheet({
format: "xlsx",
styles: {
header: {
is_bold: true,
background_color: "#2d3748",
font_color: "#ffffff",
},
},
sheets: [
{
name: "Project Budget",
columns: [
{
name: "Category",
width: 25,
},
{
name: "Q1",
width: 15,
},
{
name: "Q2",
width: 15,
},
{
name: "Q3",
width: 15,
},
{
name: "Q4",
width: 15,
},
{
name: "Annual Total",
width: 18,
},
],
rows: [
[
{
value: "Engineering",
},
{
value: 45_000,
format: "currency",
currency_code: "USD",
},
{
value: 48_000,
format: "currency",
currency_code: "USD",
},
{
value: 52_000,
format: "currency",
currency_code: "USD",
},
{
value: 50_000,
format: "currency",
currency_code: "USD",
},
{
value: "=SUM(B2:E2)",
format: "currency",
currency_code: "USD",
},
],
[
{
value: "Design",
},
{
value: 22_000,
format: "currency",
currency_code: "USD",
},
{
value: 24_000,
format: "currency",
currency_code: "USD",
},
{
value: 23_000,
format: "currency",
currency_code: "USD",
},
{
value: 25_000,
format: "currency",
currency_code: "USD",
},
{
value: "=SUM(B3:E3)",
format: "currency",
currency_code: "USD",
},
],
[
{
value: "Infrastructure",
},
{
value: 15_000,
format: "currency",
currency_code: "USD",
},
{
value: 15_000,
format: "currency",
currency_code: "USD",
},
{
value: 18_000,
format: "currency",
currency_code: "USD",
},
{
value: 20_000,
format: "currency",
currency_code: "USD",
},
{
value: "=SUM(B4:E4)",
format: "currency",
currency_code: "USD",
},
],
[
{
value: "Total",
styles: {
is_bold: true,
},
},
{
value: "=SUM(B2:B4)",
format: "currency",
currency_code: "USD",
},
{
value: "=SUM(C2:C4)",
format: "currency",
currency_code: "USD",
},
{
value: "=SUM(D2:D4)",
format: "currency",
currency_code: "USD",
},
{
value: "=SUM(E2:E4)",
format: "currency",
currency_code: "USD",
},
{
value: "=SUM(F2:F4)",
format: "currency",
currency_code: "USD",
},
],
],
},
],
});Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
from iterationlayer import IterationLayer
client = IterationLayer(api_key="YOUR_API_KEY")
result = client.generate_sheet(
format="xlsx",
styles={
"header": {
"is_bold": True,
"background_color": "#2d3748",
"font_color": "#ffffff",
},
},
sheets=[
{
"name": "Project Budget",
"columns": [
{
"name": "Category",
"width": 25,
},
{
"name": "Q1",
"width": 15,
},
{
"name": "Q2",
"width": 15,
},
{
"name": "Q3",
"width": 15,
},
{
"name": "Q4",
"width": 15,
},
{
"name": "Annual Total",
"width": 18,
},
],
"rows": [
[
{
"value": "Engineering",
},
{
"value": 45000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 48000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 52000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 50000,
"format": "currency",
"currency_code": "USD",
},
{
"value": "=SUM(B2:E2)",
"format": "currency",
"currency_code": "USD",
},
],
[
{
"value": "Design",
},
{
"value": 22000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 24000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 23000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 25000,
"format": "currency",
"currency_code": "USD",
},
{
"value": "=SUM(B3:E3)",
"format": "currency",
"currency_code": "USD",
},
],
[
{
"value": "Infrastructure",
},
{
"value": 15000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 15000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 18000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 20000,
"format": "currency",
"currency_code": "USD",
},
{
"value": "=SUM(B4:E4)",
"format": "currency",
"currency_code": "USD",
},
],
[
{
"value": "Total",
"styles": {
"is_bold": True,
},
},
{
"value": "=SUM(B2:B4)",
"format": "currency",
"currency_code": "USD",
},
{
"value": "=SUM(C2:C4)",
"format": "currency",
"currency_code": "USD",
},
{
"value": "=SUM(D2:D4)",
"format": "currency",
"currency_code": "USD",
},
{
"value": "=SUM(E2:E4)",
"format": "currency",
"currency_code": "USD",
},
{
"value": "=SUM(F2:F4)",
"format": "currency",
"currency_code": "USD",
},
],
],
},
],
)Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
package main
import il "github.com/iterationlayer/sdk-go"
func main() {
client := il.NewClient("YOUR_API_KEY")
result, err := client.GenerateSheet(il.GenerateSheetRequest{
Format: "xlsx",
Styles: &il.SheetStyles{
Header: &il.CellStyle{
IsBold: true,
BackgroundColor: "#2d3748",
FontColor: "#ffffff",
},
},
Sheets: []il.Sheet{
{
Name: "Project Budget",
Columns: []il.SheetColumn{
{
Name: "Category",
Width: 25,
},
{
Name: "Q1",
Width: 15,
},
{
Name: "Q2",
Width: 15,
},
{
Name: "Q3",
Width: 15,
},
{
Name: "Q4",
Width: 15,
},
{
Name: "Annual Total",
Width: 18,
},
},
Rows: []il.SheetRow{
{
{
Value: "Engineering",
},
{
Value: 45000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 48000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 52000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 50000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=SUM(B2:E2)",
Format: "currency",
CurrencyCode: "USD",
},
},
{
{
Value: "Design",
},
{
Value: 22000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 24000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 23000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 25000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=SUM(B3:E3)",
Format: "currency",
CurrencyCode: "USD",
},
},
{
{
Value: "Infrastructure",
},
{
Value: 15000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 15000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 18000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 20000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=SUM(B4:E4)",
Format: "currency",
CurrencyCode: "USD",
},
},
{
{
Value: "Total",
Styles: &il.CellStyle{
IsBold: true,
},
},
{
Value: "=SUM(B2:B4)",
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=SUM(C2:C4)",
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=SUM(D2:D4)",
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=SUM(E2:E4)",
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=SUM(F2:F4)",
Format: "currency",
CurrencyCode: "USD",
},
},
},
},
},
})
if err != nil {
panic(err)
}
_ = result
}Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}When Excel opens this file, every formula evaluates natively. The “Annual Total” column sums each row. The “Total” row sums each column. The bottom-right cell gives you the grand total.
If you request CSV or Markdown format with the same payload, the API evaluates the formulas server-side and writes the computed values. Same data, same structure, correct output in every format.
The Full Example
Putting it all together — styled headers, formatted numbers, formulas, column widths — here’s a complete request you can copy and run:
Request
curl -X POST https://api.iterationlayer.com/sheet-generation/v1/generate \
-H "Authorization: Bearer $API_KEY" \
-H "Content-Type: application/json" \
-d '{
"format": "xlsx",
"styles": {
"header": {
"is_bold": true,
"font_size_in_pt": 11,
"background_color": "#2d3748",
"font_color": "#ffffff",
"horizontal_alignment": "center"
},
"body": {
"font_size_in_pt": 10
}
},
"sheets": [
{
"name": "Q1 Summary",
"columns": [
{
"name": "Department",
"width": 20
},
{
"name": "Headcount",
"width": 12
},
{
"name": "Budget",
"width": 16
},
{
"name": "Spent",
"width": 16
},
{
"name": "Remaining",
"width": 16
}
],
"rows": [
[
{
"value": "Engineering"
},
{
"value": 12,
"format": "number"
},
{
"value": 180000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 145000,
"format": "currency",
"currency_code": "USD"
},
{
"value": "=C2-D2",
"format": "currency",
"currency_code": "USD"
}
],
[
{
"value": "Design"
},
{
"value": 5,
"format": "number"
},
{
"value": 75000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 68000,
"format": "currency",
"currency_code": "USD"
},
{
"value": "=C3-D3",
"format": "currency",
"currency_code": "USD"
}
],
[
{
"value": "Marketing"
},
{
"value": 8,
"format": "number"
},
{
"value": 120000,
"format": "currency",
"currency_code": "USD"
},
{
"value": 95000,
"format": "currency",
"currency_code": "USD"
},
{
"value": "=C4-D4",
"format": "currency",
"currency_code": "USD"
}
],
[
{
"value": "Total",
"styles": {
"is_bold": true
}
},
{
"value": "=SUM(B2:B4)",
"format": "number",
"styles": {
"is_bold": true
}
},
{
"value": "=SUM(C2:C4)",
"format": "currency",
"currency_code": "USD",
"styles": {
"is_bold": true
}
},
{
"value": "=SUM(D2:D4)",
"format": "currency",
"currency_code": "USD",
"styles": {
"is_bold": true
}
},
{
"value": "=SUM(E2:E4)",
"format": "currency",
"currency_code": "USD",
"styles": {
"is_bold": true
}
}
]
]
}
]
}'Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
import { IterationLayer } from "iterationlayer";
const client = new IterationLayer({
apiKey: "YOUR_API_KEY",
});
const result = await client.generateSheet({
format: "xlsx",
styles: {
header: {
is_bold: true,
font_size_in_pt: 11,
background_color: "#2d3748",
font_color: "#ffffff",
horizontal_alignment: "center",
},
body: {
font_size_in_pt: 10,
},
},
sheets: [
{
name: "Q1 Summary",
columns: [
{
name: "Department",
width: 20,
},
{
name: "Headcount",
width: 12,
},
{
name: "Budget",
width: 16,
},
{
name: "Spent",
width: 16,
},
{
name: "Remaining",
width: 16,
},
],
rows: [
[
{
value: "Engineering",
},
{
value: 12,
format: "number",
},
{
value: 180_000,
format: "currency",
currency_code: "USD",
},
{
value: 145_000,
format: "currency",
currency_code: "USD",
},
{
value: "=C2-D2",
format: "currency",
currency_code: "USD",
},
],
[
{
value: "Design",
},
{
value: 5,
format: "number",
},
{
value: 75_000,
format: "currency",
currency_code: "USD",
},
{
value: 68_000,
format: "currency",
currency_code: "USD",
},
{
value: "=C3-D3",
format: "currency",
currency_code: "USD",
},
],
[
{
value: "Marketing",
},
{
value: 8,
format: "number",
},
{
value: 120_000,
format: "currency",
currency_code: "USD",
},
{
value: 95_000,
format: "currency",
currency_code: "USD",
},
{
value: "=C4-D4",
format: "currency",
currency_code: "USD",
},
],
[
{
value: "Total",
styles: {
is_bold: true,
},
},
{
value: "=SUM(B2:B4)",
format: "number",
styles: {
is_bold: true,
},
},
{
value: "=SUM(C2:C4)",
format: "currency",
currency_code: "USD",
styles: {
is_bold: true,
},
},
{
value: "=SUM(D2:D4)",
format: "currency",
currency_code: "USD",
styles: {
is_bold: true,
},
},
{
value: "=SUM(E2:E4)",
format: "currency",
currency_code: "USD",
styles: {
is_bold: true,
},
},
],
],
},
],
});Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
from iterationlayer import IterationLayer
client = IterationLayer(api_key="YOUR_API_KEY")
result = client.generate_sheet(
format="xlsx",
styles={
"header": {
"is_bold": True,
"font_size_in_pt": 11,
"background_color": "#2d3748",
"font_color": "#ffffff",
"horizontal_alignment": "center",
},
"body": {
"font_size_in_pt": 10,
},
},
sheets=[
{
"name": "Q1 Summary",
"columns": [
{
"name": "Department",
"width": 20,
},
{
"name": "Headcount",
"width": 12,
},
{
"name": "Budget",
"width": 16,
},
{
"name": "Spent",
"width": 16,
},
{
"name": "Remaining",
"width": 16,
},
],
"rows": [
[
{
"value": "Engineering",
},
{
"value": 12,
"format": "number",
},
{
"value": 180000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 145000,
"format": "currency",
"currency_code": "USD",
},
{
"value": "=C2-D2",
"format": "currency",
"currency_code": "USD",
},
],
[
{
"value": "Design",
},
{
"value": 5,
"format": "number",
},
{
"value": 75000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 68000,
"format": "currency",
"currency_code": "USD",
},
{
"value": "=C3-D3",
"format": "currency",
"currency_code": "USD",
},
],
[
{
"value": "Marketing",
},
{
"value": 8,
"format": "number",
},
{
"value": 120000,
"format": "currency",
"currency_code": "USD",
},
{
"value": 95000,
"format": "currency",
"currency_code": "USD",
},
{
"value": "=C4-D4",
"format": "currency",
"currency_code": "USD",
},
],
[
{
"value": "Total",
"styles": {
"is_bold": True,
},
},
{
"value": "=SUM(B2:B4)",
"format": "number",
"styles": {
"is_bold": True,
},
},
{
"value": "=SUM(C2:C4)",
"format": "currency",
"currency_code": "USD",
"styles": {
"is_bold": True,
},
},
{
"value": "=SUM(D2:D4)",
"format": "currency",
"currency_code": "USD",
"styles": {
"is_bold": True,
},
},
{
"value": "=SUM(E2:E4)",
"format": "currency",
"currency_code": "USD",
"styles": {
"is_bold": True,
},
},
],
],
},
],
)Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Request
package main
import il "github.com/iterationlayer/sdk-go"
func main() {
client := il.NewClient("YOUR_API_KEY")
result, err := client.GenerateSheet(il.GenerateSheetRequest{
Format: "xlsx",
Styles: &il.SheetStyles{
Header: &il.CellStyle{
IsBold: true,
FontSizeInPt: 11,
BackgroundColor: "#2d3748",
FontColor: "#ffffff",
HorizontalAlignment: "center",
},
Body: &il.CellStyle{
FontSizeInPt: 10,
},
},
Sheets: []il.Sheet{
{
Name: "Q1 Summary",
Columns: []il.SheetColumn{
{
Name: "Department",
Width: 20,
},
{
Name: "Headcount",
Width: 12,
},
{
Name: "Budget",
Width: 16,
},
{
Name: "Spent",
Width: 16,
},
{
Name: "Remaining",
Width: 16,
},
},
Rows: []il.SheetRow{
{
{
Value: "Engineering",
},
{
Value: 12,
Format: "number",
},
{
Value: 180000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 145000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=C2-D2",
Format: "currency",
CurrencyCode: "USD",
},
},
{
{
Value: "Design",
},
{
Value: 5,
Format: "number",
},
{
Value: 75000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 68000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=C3-D3",
Format: "currency",
CurrencyCode: "USD",
},
},
{
{
Value: "Marketing",
},
{
Value: 8,
Format: "number",
},
{
Value: 120000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: 95000,
Format: "currency",
CurrencyCode: "USD",
},
{
Value: "=C4-D4",
Format: "currency",
CurrencyCode: "USD",
},
},
{
{
Value: "Total",
Styles: &il.CellStyle{
IsBold: true,
},
},
{
Value: "=SUM(B2:B4)",
Format: "number",
Styles: &il.CellStyle{
IsBold: true,
},
},
{
Value: "=SUM(C2:C4)",
Format: "currency",
CurrencyCode: "USD",
Styles: &il.CellStyle{
IsBold: true,
},
},
{
Value: "=SUM(D2:D4)",
Format: "currency",
CurrencyCode: "USD",
Styles: &il.CellStyle{
IsBold: true,
},
},
{
Value: "=SUM(E2:E4)",
Format: "currency",
CurrencyCode: "USD",
Styles: &il.CellStyle{
IsBold: true,
},
},
},
},
},
},
})
if err != nil {
panic(err)
}
_ = result
}Response
{
"success": true,
"data": {
"buffer": "UEsDBBQAAAAIAA...",
"mime_type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}
}Next Steps
The Sheet Generation docs cover the full API reference — all cell formats, style properties, cell merging, custom fonts, and multi-sheet support.
If you’re generating spreadsheets from extracted document data, the Document Extraction to Spreadsheet pipeline walks through the end-to-end workflow.