ChartQuery Java SDK

The official Java SDK for the ChartQuery chart and QR code API.

Generate chart images, diagrams, barcodes, QR codes and thermal labels on demand. PNG, SVG or PDF output.

The SDK exposes 20 typed methods, one per documented endpoint, each with a parameter builder, plus a generic request(). It uses java.net.http.HttpClient and Jackson.

Requirements

• Java 17 or newer

Installation

The SDK is not on Maven Central. Build it from source, which installs it in your local Maven repository:

git clone https://github.com/chartquery/chartquery-java.git
cd chartquery-java
mvn -q install -DskipTests

Then add it to your project. Maven:

<dependency>
  <groupId>com.chartquery</groupId>
  <artifactId>chartquery</artifactId>
  <version>0.1.0</version>
</dependency>

Gradle, with mavenLocal() in your repositories:

implementation("com.chartquery:chartquery:0.1.0")

Get your API key

Sign up for ChartQuery or sign in, then copy your API key from the dashboard. ChartQueryClient.fromEnv() reads the CHARTQUERY_API_KEY environment variable.

Quick start

import com.chartquery.ApiResponse;
import com.chartquery.ChartQueryClient;
import com.chartquery.params.ChartAiParams;

ChartQueryClient client = ChartQueryClient.fromEnv();
ApiResponse response = client.chartAi(ChartAiParams.builder().prompt("Monthly revenue 2026 as a bar chart: Jan 10, Feb 14, Mar 18").build());
System.out.println(response.json().toPrettyString());

Parameter builders mirror the API reference; build() checks required parameters. Use response.as(MyType.class) to map the JSON onto your own types.

Binary responses

Endpoints that return a file (image, PDF…) give you the bytes; isJson() tells both cases apart:

ApiResponse response = client.qrcode(QrcodeParams.builder().data("https://chartquery.com").format("png").build());
if (!response.isJson()) {
  java.nio.file.Files.write(java.nio.file.Path.of("qrcode.png"), response.bytes());
}

Async jobs

Any call accepts is_async: true (useful past the 60-second server limit): the response is then a job_id. waitForJob polls GET /v1/jobs/{id} until a terminal status (CompletedJob, Error, NotFound, BadRequest):

ApiResponse submitted = client.chartAi(ChartAiParams.builder().prompt("Monthly revenue 2026 as a bar chart: Jan 10, Feb 14, Mar 18").isAsync(true).build());
ApiResponse job = client.waitForJob(
    submitted.json().get("job_id").asText(),
    Duration.ofSeconds(3),
    Duration.ofHours(12),
    progress -> System.out.println(progress.path("status").asText() + " " + progress.path("progress").asInt()));

GET or POST

Methods use GET when the endpoint supports it (query string). POST sends the same parameters as JSON:

client.barcode(BarcodeParams.builder().data("test").build(), RequestOptions.method("POST"));

Any endpoint

ApiResponse response = client.request("GET", "/v1/usage", Map.of());

Errors

try {
  client.chartAi(ChartAiParams.builder().prompt("Monthly revenue 2026 as a bar chart: Jan 10, Feb 14, Mar 18").build());
} catch (ChartQueryApiException e) {
  System.err.println(e.status() + ": " + e.getMessage());
}

Exception	When
ChartQueryConfigurationException	Missing API key, invalid options or unsupported method.
ChartQuerySerializationException	A required parameter is missing or a value can't be sent.
ChartQueryTransportException	Network failure, timeout or interruption.
ChartQueryApiException	Non-2xx status (status(), errorMessage(), responseBody(), rawResponse()).
ChartQueryResponseDecodingException	A success response could not be decoded.

All of them extend the unchecked ChartQueryException.

Retries

Requests are retried up to 3 times after a network error, a 408, 500, 502, 503 or 504, or a rate limit — which the API returns as 401 (or 429) with a Rate limit exceeded message. Per-key quota errors (…: quota daily) are not retried, nor are 400, 402, 404 or client-side timeouts. The delay starts at 1 second and grows 1.5× per retry (capped at 30 seconds); a Retry-After header wins.

ChartQueryClient client = ChartQueryClient.builder().maxRetries(5).retryDelay(Duration.ofMillis(500)).build();
client.chartAi(ChartAiParams.builder().prompt("Monthly revenue 2026 as a bar chart: Jan 10, Feb 14, Mar 18").build(), RequestOptions.builder().maxRetries(0).build()); // one request without retries

Batch requests

batch() runs a function per item on 10 threads (concurrency) and returns one BatchResult per item, in input order. A failing item never stops the others.

List<String> inputs = List.of("Monthly revenue 2026 as a bar chart: Jan 10, Feb 14, Mar 18", "Market share as a pie chart: A 40, B 35, C 25");
List<BatchResult<ApiResponse>> results = client.batch(inputs, 5, value ->
    client.chartAi(ChartAiParams.builder().prompt(value).build()));
for (BatchResult<ApiResponse> result : results) {
  if (result.ok()) {
    System.out.println(result.value().json());
  } else {
    System.err.println(inputs.get(result.index()) + ": " + result.error().getMessage());
  }
}

Constant	Default	Description
ChartQueryClient.DEFAULT_CONCURRENCY	10	Tasks run at the same time by batch
ChartQueryClient.DEFAULT_TIMEOUT	Duration.ofSeconds(120)	Request timeout
ChartQueryClient.MAX_RETRIES	3	Retry attempts after a network error, a 408/5xx or a rate limit
ChartQueryClient.RETRY_BACKOFF_FACTOR	1.5	Exponential backoff multiplier
ChartQueryClient.DEFAULT_RETRY_DELAY	Duration.ofSeconds(1)	Delay before the first retry

Configuration

ChartQueryClient client = ChartQueryClient.builder()
    .apiKey(System.getenv("CHARTQUERY_API_KEY"))
    .timeout(Duration.ofSeconds(60)) // default 120 s, null disables
    .header("X-Trace", "abc")
    .transport(ChartQueryTransport.fromHttpClient(myHttpClient)) // optional
    .build();

Endpoints

20 methods, generated from the OpenAPI document.

Method	HTTP	Description
barcode()	GET / POST /v1/barcode	Generate a barcode image via GET. Output: SVG (default) or PNG. Supports 25+ formats: EAN-13, Code 128, ITF-14, GS1-128, postal codes and m…
chart()	GET / POST /v1/chart	Render a Chart.js image via GET. Pass the full chart object as URL-encoded JSON in query. Prefer format png for ChatGPT. POST sends the sam…
chartAi()	GET / POST /v1/chart/ai	Describe a chart in plain English via GET and get a rendered image back. Powered by AI.
chartRender()	GET /v1/chart/render/{id}	Render a previously saved chart by ID. Public, no API key required. Supports URL overrides for templates (?data1=, ?labels=, ?title=…).
chartView()	GET /v1/chart/view/{id}	View a previously saved chart as an interactive HTML page. Public, no API key required. Iframe-embeddable.
diagram()	GET / POST /v1/diagram	Render a diagram via GET. Use type (mermaid, d2, …), query (source code), and format=png for ChatGPT. POST uses diagram_type and diagram_so…
diagramAi()	GET / POST /v1/diagram/ai	Describe a diagram in plain English via GET and get a rendered image back. Powered by AI.
diagramRender()	GET /v1/diagram/render/{id}	Render a previously saved diagram by ID. Public, no API key required. Supports ?format= and ?query= overrides.
diagramView()	GET /v1/diagram/view/{id}	View a previously saved diagram as an HTML page. Public, no API key required. Iframe-embeddable with inline SVG rendering.
jobs()	GET /v1/jobs/{id}	Poll the status, progress (0–100) and result of a job started with is_async=true. Polling is free. Poll until status is terminal: Completed…
label()	GET / POST /v1/label	Preview a thermal label via GET. Pass the same label object as a URL-encoded JSON string in query. Inside that JSON, text items use content…
labelCompile()	POST /v1/label/compile	Compile a label to printer commands (tsc, zpl, epl, …). POST width, language, and elements. Text uses content and size (1-10), not text or…
labelConvert()	POST /v1/label/convert	Convert printer commands from one language to another. POST source, from, and to. from is the source language (tsc, zpl, epl, …). to is the…
labelParse()	POST /v1/label/parse	Parse printer commands into structured elements. POST source and language (tsc, zpl, epl, …).
labelRender()	GET /v1/label/render/{id}	Render a previously saved label by ID. Public, no API key required. Supports ?format= override.
labelValidate()	POST /v1/label/validate	Validate printer commands. POST source (the raw commands) and language (tsc, zpl, epl, …).
labelView()	GET /v1/label/view/{id}	View a previously saved label as an HTML page. Public, no API key required. Iframe-embeddable with inline SVG rendering.
qrcode()	GET / POST /v1/qrcode	Generate a styled QR code via GET. Output: SVG (default) or PNG. Supports dot styles, gradients, custom corners and all QR versions.
stats()	GET /v1/stats	Infrastructure health for an engine or endpoint over the last hour. Not scoped to your account or tenant. Enabled per account: HTTP 403 mea…
usage()	GET /v1/usage	Return this account's Chartquery usage and credit balance. No body. Requires an API key.

All ChartQuery SDKs

SDK	Package	Install
Node.js	@chartquery/sdk	npm install @chartquery/sdk
Python	chartquery	pip install chartquery
Go	chartquery-go	go get github.com/chartquery/chartquery-go
.NET	ChartQuery	dotnet add package ChartQuery
Ruby	chartquery	gem install chartquery
PHP	chartquery/sdk	composer require chartquery/sdk
Java	chartquery-java	build from source, see its README
CLI	@chartquery/cli	npm install -g @chartquery/cli
MCP server	@chartquery/mcp	npx -y @chartquery/mcp

License

MIT — see LICENSE.