First-party app
QuickChart

QuickChart

Render charts, QR codes, barcodes, word clouds, tables, Graphviz diagrams and watermarked images as images with QuickChart, and save a chart to a short URL.

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About

QuickChart ships in the w6w first-party pack. It declares 13 actions, 2 health checks, and the host runs its code in a sandbox that never sees the credential.

App id
io.w6w.quickchart
Version
0.1.0
Author
w6w
Licence
MIT
Categories
Analytics & BI · Developer Tools · Documents & Files

Overview

QuickChart turns a description into an image. This app exposes its rendering APIs to a workflow.

A workflow can render a Chart.js chart (Chart.js v2, v3 or v4) to PNG, JPEG, WebP, SVG or PDF, save a chart to a short URL that can be dropped into an email or chat message, validate a chart before rendering it, and draft a Chart.js config from a plain-English description. It can also render QR codes (styled, with a centre logo or caption) and read one back from an image, render barcodes in over a hundred symbologies, word clouds, tables, Graphviz diagrams, and watermark one image onto another.

No account is needed: the API answers anonymously within a shared rate limit. A paid API key can be added to the connection for higher limits and longer-lived short URLs; without a connection every action still runs. Images are written to the run’s file store and returned as a file reference; SVG output also comes back as text.

Build with QuickChart

Three routes to the same 13 actions. The Workflow tab is generated from QuickChart's own manifest and carries its real ids, so it is copy-pasteable; the Code and CLI examples are the same call for any action on any app, so every app-specific value in them is a blank you fill in.

Render Barcode

barcode-render

Render a barcode (Code 128, EAN, UPC, Data Matrix and 100+ more) to an image.

Draft Chart From Description

chart-draft-from-text

Draft a Chart.js config (and a saved image URL) from a plain-English description.

Render Chart

chart-render

Render a Chart.js chart to a PNG, JPEG, WebP, SVG or PDF image.

Create Chart Short URL

chart-url-create

Save a Chart.js chart and get a short URL that renders it, for email, SMS or chat.

Validate Chart

chart-validate

Check a Chart.js config renders, and get errors and warnings as JSON.

Render Graphviz Diagram

graphviz-render

Render a Graphviz DOT graph to SVG or PNG.

Read QR Code

qr-read

Decode the text of a QR code in an image.

Render QR Code

qr-render

Render a QR code (optionally styled, with a centre image or caption) to an image.

Build QR Code URL

qr-url-build

Get a URL that renders a QR code, without rendering it now.

Validate QR Code

qr-validate

Check a QR code request is valid, with errors and warnings as JSON.

Render Table

table-render

Render a table of rows and columns as a PNG image.

Add Watermark

watermark-apply

Overlay a watermark or logo image onto a base image.

Render Word Cloud

wordcloud-render

Render a word cloud from text or a word:count list.

A workflow step names the app and the action, and the editor fills in the connection when you pick one. This is the Step shape from the workflow spec, carrying QuickChart's real ids.

{
  "manifestVersion": "2",
  "name": "quickchart-example",
  "steps": [
    {
      "id": "barcode-render",
      "uses": {
        "app": "io.w6w.quickchart",
        "action": "barcode-render",
        "connection": "conn_YOUR_CONNECTION_ID"
      },
      "with": {
        "type": "<type>",
        "text": "<text>"
      }
    }
  ]
}

Here are some of the things you can do

  • Render Barcode

    perform
    barcode-render
  • Draft Chart From Description

    perform
    chart-draft-from-text
  • Render Chart

    perform
    chart-render
  • Create Chart Short URL

    perform
    chart-url-create
  • Validate Chart

    read
    chart-validate

+8 more actions available

Every app-specific value here is a blank you have to fill in. An app action is reached through the connection that authenticates it, so the address is a connection id, not the app id — and connections belong to your account, so a public page cannot know yours. Create one for QuickChart, then fill in the three blanks: conn_YOUR_CONNECTION_ID, the action key, and the parameters that action declares. The call itself is real — the shape is transcribed from the studio's own snippet builder, which prints the same kind of blanks — but nothing in it is specific to QuickChart. The Workflow tab is where this app's real ids are.

Install
npm install @w6w/sdk
yarn add @w6w/sdk
pnpm add @w6w/sdk
deno add npm:@w6w/sdk
Code
import { W6wClient, isActionRun } from "@w6w/sdk";

// Reads W6W_BASE_URL and W6W_TOKEN from the environment when omitted.
const client = new W6wClient();

const envelope = await client.run({
  urn: "conn_YOUR_CONNECTION_ID",
  action: "barcode-render",
  payload: {
    type: "<value>",
    text: "<value>",
    // format: "<value>",
    // width: "<value>",
    // height: "<value>",
    // scale: "<value>",
    // includeText: "<value>",
    // rotate: "<value>",
  },
});

if (isActionRun(envelope)) console.log(envelope.value);
Install the CLI
npm install -g @w6w/cli
CLI
w6w run conn_YOUR_CONNECTION_ID --action barcode-render --payload '{"type":"<value>","text":"<value>"}'

Give an AI agent QuickChart — without giving it QuickChart's credentials. One MCP endpoint exposes every app, function and workflow the caller is entitled to, as tools it can discover and run. Access is granted per team while we onboard.

One tool call
{
  "name": "w6w_invoke",
  "arguments": {
    "ref": "app:io.w6w.quickchart#barcode-render",
    "input": {
      "type": "<type>",
      "text": "<text>"
    }
  }
}

Every tool names its target with a single ref. The app: form above doesn't name a connection at all — the host resolves which of the caller's QuickChart connections to sign with, and refuses rather than guesses when the answer is ambiguous.

What the agent gets

Credentials it can't read

The token is attached host-side, at the moment of the call. It is never a tool argument, never in the model's context, and never in a transcript — so a prompt injection has nothing to exfiltrate.

A tool surface scoped to the caller

Tools are derived per end user from what that person has actually connected and is entitled to — not one shared bot identity carrying the union of everyone's access.

A durable workflow in one call

Multi-step work runs on the workflow engine and returns a run handle the agent can poll — retries, branching and state survive the conversation that started them.

Health-aware discovery

QuickChart's declared health checks are on the surface too, so an agent can tell "the vendor is down" from "your credential expired" before it burns a retry on either.

The MCP surface is part of the hosted platform. QuickChart itself is MIT, and the runtime that executes it is source-available (FSL).

Request MCP access

Health checks

QuickChart declares its own checks, so its health is a property of the app rather than something the host guesses at.

service

QuickChart reachable

GET /healthcheck — expects {success: true, version}.

quota

Rate-limit headroom