AltText.ai is a service that automatically generates alt text for images, enhancing accessibility and SEO.
AltText.ai is a service that automatically generates alt text for images, enhancing accessibility and SEO. On Nagent, AltText.ai is exposed as a fully-configurable artificial intelligence integration that any agent can call — 10 actions, and API key authentication. No code is required to wire AltText.ai into your workflow — connect it once via the External Integrations panel and reuse it across every agent you build.
Agent builders use AltText.ai to automate the kinds of tasks artificial intelligence teams previously handled manually. Concrete examples — each one is a single agent step in Nagent — include:
Every action and trigger is paired with a structured input/output schema (visible in the sections below), so when you wire AltText.ai into Helix — our agentic agent builder — the editor knows exactly what each step expects and produces. Configure once, deploy anywhere across your Nagent agents.
Every operation an agent can call against AltText.ai, with input parameters and output schema. Drop these into any step of an agent built in Helix.
ALTTEXT_AI_CREATE_BULK_IMAGESTool to bulk upload and process a CSV file of image URLs for alt text generation. Use when you need to process multiple images at once (up to 100,000 URLs). Invalid rows are returned in row_errors for debugging.
Input parameters
CSV file containing image URLs to process. The CSV should have a 'url' column with image URLs. Maximum 100000 rows.
Optional email address to receive results of the bulk upload when processing is complete.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_CREATE_IMAGETool to add an image and generate alt text. Supports both URL and base64-encoded file upload. Use when you need to generate alt text for images, with options for custom prompts, keywords, multiple languages, and ecommerce data. Rate limited to 4 calls per second.
Input parameters
Language code(s) for alt text generation. Use comma-separated values for multiple languages (e.g., 'en,es,fr'). Default is 'en'.
Ecommerce data for product images.
Image data object containing URL or base64-encoded data. Either url or raw field must be provided.
Keywords or phrases for SEO-optimized alt text. Maximum 6 items.
Maximum length of generated alt text. Must be between 80 and 500 characters.
Force regeneration of alt text for existing image. Default false.
Whether to add the image in the background. If true, returns immediately with processing status. Default false.
ChatGPT prompt to apply to generated alt text. Use {{AltText}} macro to reference the initial alt text.
Available language models for alt text generation.
Alternative webhook URL for this operation to receive async notifications
Maximum timeout in seconds for alt text generation. Must be between 5 and 30 seconds. Default is 12.
Text source for extracting keywords if keywords array is blank
Keywords to remove from generated alt text. Maximum 6 items.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_DELETE_IMAGE_BY_ASSET_IDTool to delete an image from your library by its asset ID. Use when you need to remove a specific image permanently from your AltText.ai account.
Input parameters
The asset ID of the image to delete from your library.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_GET_ACCOUNTTool to retrieve account settings and usage information. Use when you need to check your AltText.ai account configuration and usage limits before generating alt text.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_GET_IMAGE_BY_ASSET_IDTool to retrieve detailed information about a specific image using its asset ID. Use when you need to fetch alt text, metadata, or status of a previously processed image.
Input parameters
The unique asset ID of the image to retrieve. This is returned when creating or listing images.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_GET_IMAGESTool to retrieve a paginated list of images in your library, including their alt text and metadata. Use when you need to browse or filter images programmatically after authentication.
Input parameters
Exact URL to filter images by. Must match the stored image URL exactly; no wildcards.
Page number to retrieve, starting at 1.
Number of images per page (max 100).
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_SCRAPE_PAGETool to scrape a web page or HTML document and queue all images for alt text generation. Images are processed asynchronously. Does not execute JavaScript. Use when you need to batch-process images from a website or HTML content.
Input parameters
Language code(s) for alt text generation. Use comma-separated values for multiple languages (e.g., 'en,es').
Keywords for SEO-optimized alt text. Maximum 6 items. Must be in English.
Page scrape configuration containing URL or HTML to process.
If true, process images that already have alt text. Defaults to false if not specified.
Keywords to exclude from generated alt text. Maximum 6 items. Must be in English.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_SEARCH_IMAGESSearch for images in your AltText.ai library by keywords. Searches through your previously processed images to find matches based on URLs, alt text content, and metadata. Useful for finding specific images in large libraries. Returns paginated results with alt text and metadata. Note: This searches your own image library, not a public image database. Images must be added via the Create Image endpoint before they can be searched.
Input parameters
Page number for paginated results, starting at 1.
Search keywords or phrase to find images in your library. Searches against image URLs, alt text content, and associated metadata.
Number of results to return per page (1-100).
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_UPDATE_ACCOUNTTool to update account settings (e.g., webhook_url, name). Use after confirming current account details to modify settings.
Input parameters
Account settings to update, nested object.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
ALTTEXT_AI_UPDATE_IMAGE_BY_ASSET_IDTool to update an image with new data including asset ID, alt text, and metadata. Use when you need to modify existing image information. Note: You cannot update the URL of an existing image.
Input parameters
Language code(s) for the updated alt text.
Image data to update. Note: You cannot update the URL of an existing image.
The asset ID of the image to update.
Whether to overwrite existing alt text. Default false.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
No publicly available marketplace agent is found using this tool yet. There are 71 agents privately built on Nagent that already use AltText.ai.
Build on Nagent
Connect AltText.ai to any Nagent agent in minutes — no API key management, no boilerplate. Just configure and deploy.
The five questions agent builders ask before adopting a new integration.
Open the External Integrations panel inside Nagent (app.nagent.ai/externalIntegration), find AltText.ai, and click "Connect Now." You'll authenticate with an API key — Nagent handles credential storage and refresh automatically. Once connected, AltText.ai is available to any agent in your workspace.
No. Nagent provides no-code integration for every tool. Once AltText.ai is connected, you configure its 10 actions directly in the agent builder UI — no API calls, no boilerplate, no schema management.
Helix — Nagent's agentic agent builder — lets you drop AltText.ai steps into any workflow visually. Pick an action (e.g., one of those listed above), fill in the inputs (Helix knows the required vs. optional schema for each parameter), and connect it to upstream/downstream steps. Triggers run as the entry point of an agent, so when a AltText.ai event fires, the agent kicks off automatically.
Every AltText.ai action and trigger ships with a fully-typed schema — input parameters with name, type, required flag, and description, plus the output payload shape. The schemas are documented in the sections above. Helix uses these schemas to validate your configuration at build time and to type-check the data flowing between steps.
Yes. While AltText.ai ships with 10 pre-built artificial intelligence actions, you can layer custom logic around them inside Helix — pre/post-processing steps, conditional branches, retries, or stitching AltText.ai together with other connected tools. For deeper customization, talk to our team about Nagent's Agentic AI Lab — forward-deployed engineers who build AltText.ai-based workflows tailored to your business.