Install Jentic One Beta

Connect the Image-Charts to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Image-Charts, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.

Step 1: Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fimage-charts.com%2Fimage-charts" | sh

Step 2: Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fimage-charts.com%2Fimage-charts" | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with Image-Charts API.

Render bar, line, pie, radar, and other chart types as PNG or SVG via query parameters

Embed chart images in transactional emails where JavaScript is not allowed

Drop in as a replacement for legacy Google Image Charts URLs with the same parameter syntax

Render Chart.js 2.8.0 configurations server-side and return the resulting image

Generate sparkline-style images for dashboards rendered to PDF

GET STARTED

Start building with Image-Charts API

Explore with Jentic One

View OpenAPI Document

Use Cases

Patterns agents use Image-Charts API for, with concrete tasks.

★ Charts in Transactional Emails

Email clients block JavaScript, so interactive charts cannot run inline. Image-Charts solves this by rendering the chart as a PNG behind a URL that goes straight into an <img> tag. Marketing and product teams use it for weekly summary emails, billing reports, and onboarding nudges that include data visualisations.

Build a /chart URL with cht=bvg, chd=t:10,20,30, and chs=600x400, then put it in an <img src> tag inside the email template.

Google Image Charts Migration

Google deprecated Image Charts but many legacy systems still build chart URLs with its parameter syntax. Image-Charts re-implements the same surface, so swapping the host in existing URLs restores chart rendering without rewriting the parameter builder. This is a low-risk fix for old reporting pipelines.

Replace https://chart.googleapis.com/chart in existing URLs with https://image-charts.com/chart and verify the rendered image matches the expected output.

Server-Rendered Chart.js for PDFs

PDF generation pipelines that use headless Chrome can be slow when many charts are rendered per document. Calling /chart.js/2.8.0 with a Chart.js config returns a ready-made image, removing the headless render step. Document services use this to keep PDF generation under per-job time budgets.

Send a Chart.js config as a query parameter to /chart.js/2.8.0 and embed the returned PNG into the PDF template.

Agent-Generated Chart Embeds

An AI agent producing a Slack or email summary can include a chart by asking Jentic for the Image-Charts URL builder, supplying the data and chart type, and embedding the resulting URL in the message. Because the API requires no auth, Jentic returns the operation schema and the agent calls it directly without any credential handling.

Search Jentic for 'render a bar chart as a PNG', execute the /chart operation with cht, chd, and chs, and place the returned URL in the agent's reply.

Key Endpoints

2 endpoints — image-charts renders charts as static images directly from a url.

METHOD

PATH

DESCRIPTION

GET

/chart

Render a chart as a PNG or SVG image

GET

/chart.js/2.8.0

Render a Chart.js v2.8.0 configuration as an image

GET

/chart

Render a chart as a PNG or SVG image

GET

/chart.js/2.8.0

Render a Chart.js v2.8.0 configuration as an image

Why Jentic?

What agents get from Jentic-routed access to this vendor.

Setup

Wiring Image-Charts by hand means building the chart query string against the image-charts.com host and encoding the chart type, data, and size yourself. Through Jentic you install once, import Image-Charts from the API Directory, and your agent calls it with no key to manage on the public endpoints.

Permission scoping

The public Image-Charts endpoints take all chart settings in the request rather than in path resource ids, so scope the agent to the operations it needs, such as rendering a chart image. Because you choose the allowed operations, the agent is limited to the rendering calls you have named.

Credential isolation

Image-Charts has no required credential on its public endpoints, so there is nothing to store. If a signing key is added later, your own Jentic One instance would store it encrypted and inject it at execution time so it never enters the agent's prompt, logs, or context.

Intent-based discovery

Agents search Jentic by intent such as 'render a bar chart as a PNG', and Jentic returns the /chart or /chart.js operation with its parameter schema so the agent calls the right endpoint without browsing the reference docs.

FAQs

Specific to using Image-Charts API through Jentic.

What authentication does the Image-Charts API use?

The two public endpoints do not require authentication. Image-Charts offers paid plans that issue a signing key for higher rate limits, but the OpenAPI spec exposed here covers the unauthenticated /chart and /chart.js/2.8.0 surface.

Can I render Chart.js configurations as images with this API?

Yes. GET /chart.js/2.8.0 accepts a Chart.js v2.8.0 configuration and returns a server-rendered image. Use it when a PDF or email pipeline needs a chart image without running headless Chrome.

Is Image-Charts a true replacement for Google Image Charts?

Image-Charts re-implements the Google Image Charts URL parameter syntax (cht, chd, chs, etc.) on /chart, so replacing the host in existing URLs restores rendering for most chart types.

How do I render a chart through Jentic?

Run pip install jentic, search for 'render a bar chart as a PNG with Image-Charts', load the /chart operation schema, and execute with the chart type, data, and size parameters. The returned URL can be embedded directly in HTML or markdown.

Is the Image-Charts API free?

There is a free tier for low-volume use. Higher request volumes and watermark removal require a paid plan from image-charts.com - the OpenAPI spec itself does not cover billing.

Can I limit what my agent is allowed to do with the Image-Charts API?

Yes. Jentic One is self-hosted by you, so your own rules decide which Image-Charts operations the agent may call, and you can allow just the chart-image rendering it needs, such as the GET /chart renderer while excluding the GET /chart.js/2.8.0 endpoint. Because every chart setting travels in the request rather than in a path resource id, scoping is done at the operation level: the agent is restricted to the exact rendering calls you have named. The public endpoints require no credential, so there is nothing for the agent to hold, and it can only invoke the operations you have permitted.

Image-Charts

AI ReadinessFoundational (D)46/100

See full scorecard

Official vendor OpenAPI document · agent-readyMediaImage Processingnone2 EndpointsREST

For Agents

Render charts as PNG or SVG images by calling a single URL with chart type, data, and styling parameters - works in emails and PDFs.

Use for: I want to embed a bar chart image in a marketing email, Render a pie chart as a PNG for a printable report, Replace a broken Google Image Charts URL with a working equivalent, Generate a Chart.js configuration as a server-rendered image

Not supported: Does not handle interactive charting, data warehousing, or dashboard hosting - use for static chart image rendering via URL only.

Image-Charts renders charts as static images directly from a URL. It positions itself as a safe, fast replacement for the deprecated Google Image Charts service and supports the same chart types and parameter syntax. The API is essentially two endpoints: a /chart renderer that returns a PNG or SVG and a chart.js renderer that accepts Chart.js v2 configurations. It targets emails, dashboards, and PDFs that need an image of a chart rather than an interactive widget.

Jentic One on Github View OpenAPI Document

Show dimension breakdown

Foundational Compliance

Base layer of spec validity and structural soundness.

Grade: A-Signals: 4

90%

Lint Results

Aggregated quality score from linter diagnostics, weighted by severity.

100%

Resolution Completeness

Percentage of `$ref` references that resolve successfully.

Specification Validity

Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).

100%

Structural Integrity

Structural correctness score based on schema issues using logarithmic dampening.

Developer Experience & Jentic Compatibility

Clarity, completeness, and ingestion readiness for developers and tooling.

Grade: CSignals: 4

Example Density

How richly the API is illustrated with examples.

100%

Example Validity

Percentage of examples that conform to their schemas.

25%

Response Coverage

Percentage of operations with complete response definitions (success, client error, server error).

100%

Tooling Readiness

Health of API ingestion, bundling, and resolution within Jentic pipelines.

AI-Readiness & Agent Experience

Semantic breadth, depth, and agent comprehension for AI systems.

Grade: D+Signals: 4

48%

Description Coverage

Coverage of descriptions across API elements.

Error Standardization

Coverage of RFC 9457 Problem Details for error responses.

100%

OperationId Quality

Coverage, uniqueness, and casing consistency of operationIds for AI inference.

50%

Summary Coverage

Coverage of summaries across operations/tags/info.

Agent Usability

Functional utility, complexity comfort, and AI orchestration readiness.

Grade: A+Signals: 1

94%

Complexity Comfort

Agent comfort level based on API operational and structural complexity.

100

Security

Trust, risk posture, and security compliance.

Grade: A+Signals: 1

100%

Authentication Strength

Average quality of security schemes based on authentication method strength (weakest link for OAuth2).

AI Discoverability

Findability, semantic richness, and reasoning readiness.

Grade: FSignals: 1

12%

Descriptive Richness

Clarity and depth of descriptions across API elements.

Connect the Image-Charts to your agent

Capabilities

Start building with Image-Charts API

Use Cases

Key Endpoints

Why Jentic?

Related APIs

FAQs

Image-Charts

Jentic AI Readiness Score

Image-Charts

Foundational Compliance

Lint Results

Resolution Completeness

Specification Validity

Structural Integrity

Developer Experience & Jentic Compatibility

Example Density

Example Validity

Response Coverage

Tooling Readiness

AI-Readiness & Agent Experience

Description Coverage

Error Standardization

OperationId Quality

Summary Coverage

Agent Usability

Complexity Comfort

Security

Authentication Strength

AI Discoverability

Descriptive Richness