Install Jentic One Beta

Connect the Create Caption API to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Create Caption API, 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%2Fimagetocaptionai.com%2Fimagetocaptionai" | 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%2Fimagetocaptionai.com%2Fimagetocaptionai" | 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 Create Caption API.

Generate a caption for an image supplied by URL or upload

Drop a caption-generation step into a Zapier or n8n content workflow

Pre-fill caption fields in a social media scheduling tool from a chosen image

Generate alt-text-style descriptions for accessibility audits

Produce baseline captions that a human editor can refine before posting

GET STARTED

Start building with Create Caption API

Explore with Jentic One

View OpenAPI Document

Use Cases

Patterns agents use Create Caption API for, with concrete tasks.

★ Caption Generation in Content Pipelines

Marketing teams that schedule social posts from a queue can wire a caption-generation step in front of the scheduler. The image goes to /create-caption, the returned text is stored alongside the post, and an editor approves or edits it. This trims the time spent staring at an empty caption field for every queued image.

POST /create-caption with the image URL, store the returned caption on the queued post, and route it to the editor for approval.

Alt-Text for Accessibility Audits

Sites with thousands of marketing images often lack alt text. Looping image URLs through /create-caption produces a draft alt-text per image that a content editor can sanity-check, which is faster than writing every description from scratch. Audits that previously took weeks can be cut to days.

Iterate over a CMS image list, POST each URL to /create-caption, write the result back to the alt attribute, and flag any image where the response is empty.

Zapier and n8n Workflows

Because the API is a single POST endpoint with no auth scheme declared in the spec, it slots cleanly into low-code workflow tools. Triggers like 'new image in Drive' can call /create-caption and pipe the result into Buffer, Hootsuite, or a Notion log without any glue code.

Configure a webhook step that POSTs the new image URL to /create-caption and forwards the returned caption to the next step in the zap.

Agent-Driven Social Posting

An AI agent that drafts and schedules social posts can call this API for the caption sub-step, freeing the model from generating image-aware text without seeing the image. Through Jentic the agent searches by intent and runs the operation, then composes the final post around the returned caption.

Search Jentic for 'generate a caption for an image', execute /create-caption with the chosen image, then call the social network's posting API with the returned caption text.

Key Endpoints

1 endpoints — jentic publishes the only available openapi specification for create caption api, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

POST

/create-caption

Generate a caption for a supplied image

POST

/create-caption

Generate a caption for a supplied image

Why Jentic?

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

Setup

Wiring the Create Caption API by hand means posting the image reference to its single endpoint and shaping the request yourself. Through Jentic you install once, import the Create Caption API from the API Directory, and your agent calls it with no key to manage.

Permission scoping

The Create Caption API exposes a single caption operation with the image passed in the request body rather than a path resource id, so scope the agent to that one operation it needs. Because you choose the allowed operations, the agent is limited to caption creation.

Credential isolation

This endpoint has no required credential, so there is nothing to store. If the vendor adds a key 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 'generate a caption for an image', and Jentic returns the /create-caption operation with its input schema so the agent passes the image reference correctly on the first try without browsing the reference docs.

FAQs

Specific to using Create Caption API through Jentic.

Why is there no official OpenAPI spec for Create Caption API?

imagetocaption.ai does not publish a public OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Create Caption API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

What authentication does the Create Caption API use?

The OpenAPI spec declares no security scheme on the /create-caption endpoint. The vendor's hosted product authenticates through their dashboard rather than per-request headers; if they add a key in future, Jentic will store it encrypted in the vault.

Can I generate captions from an image URL?

Yes. POST /create-caption with the image reference and the response contains the generated caption text. The endpoint is designed for one image per call, which fits inside Zapier-style step limits.

How do I generate a caption through Jentic?

Run pip install jentic, search for 'generate a caption for an image', load the /create-caption schema, and execute with the image URL. Jentic returns the caption to the agent for use in the next step of a content workflow.

What are the rate limits for the Create Caption API?

The OpenAPI spec does not list explicit rate limits. Plan for one-image-per-call usage and back off on HTTP 429 responses if running batch jobs over hundreds of images.

Can I limit what my agent is allowed to do with the Create Caption API?

Yes. Because Jentic One is self-hosted and your own rules decide which operations an agent may call, you can scope this agent to the single POST /create-caption operation and nothing else. The API exposes only that one caption-creation operation, with the image passed in the request body rather than as a path resource, so allowing that operation limits the agent to generating captions from images. It cannot reach any other action, since you approve each operation the agent is permitted to run.

Imagetocaptionai Create Caption API

Name: Create Caption API
Brand: Create Caption API
Availability: InStock

Agent-ready OpenAPI document · curated by JenticAI/MLVisionnone1 EndpointsREST

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For Agents

Generate a social-media-style caption for a supplied image with a single POST request - useful inside content pipelines and scheduled-post agents.

Use for: I want to generate a caption for an Instagram image, Get a one-line caption for a product photo, Create alt text for an image used in a blog post, Suggest a caption for a LinkedIn announcement image

Not supported: Does not handle image hosting, post scheduling, or analytics - use for generating a caption from an image only.

Jentic publishes the only available OpenAPI specification for Create Caption API, keeping it validated and agent-ready. Create Caption API exposes a single endpoint that takes an image and returns a generated caption. The service is positioned as a Zapier-friendly building block for social media managers who want descriptive, on-brand captions for Instagram, LinkedIn, and similar feeds. The API accepts an image reference and returns the caption text in a JSON response.

Jentic One on Github View OpenAPI Document