These tools expose an API, so you can call them from your own code rather than working through their interface. This is the list to start from if you are building AI into a product, a script or an automation.
Decagon AI provides conversational AI assistance for users who want interactive answers, follow-ups and task-f...
Freemium
Free plan API
DeepSeek helps users with reasoning assistant through an interactive AI chat experience.
Free
Free plan API
Definite provides AI-assisted capabilities for modern software or AI workflows.
Paid
API
DSPy helps developers framework for programming and optimizing language-model pipelines rather than manually c...
Free
Free plan API Open source
Exa provides conversational AI assistance for users who want interactive answers, follow-ups and task-focused...
Freemium
Free plan API
Five9 AI provides conversational AI assistance for users who want interactive answers, follow-ups and task-foc...
Freemium
Free plan API
Front AI provides conversational AI assistance for users who want interactive answers, follow-ups and task-foc...
Freemium
Free plan API
Gemini helps writers turn prompts, drafts, files, and content from supported Google services into drafts, rewr...
Freemium
Free plan API
Hume AI provides expressive voice for creators, businesses, educators, and developers who need practical audio...
Freemium
Free plan API
Julius AI provides AI-assisted capabilities for modern software or AI workflows.
Paid
API
Kits AI provides AI vocals for creators, businesses, educators, and developers who need practical audio workfl...
Freemium
Free plan API
Kombai helps developers ai tool for converting design files and screenshots into frontend code..
Paid
API
Mage helps creators generate, edit, or enhance images for practical design and visual-content tasks.
Freemium
Free plan API Open source
Visual automation platform for connecting applications, transforming data, and building multi-step workflows.
Freemium
Free plan API
Mem helps writers turn notes, saved information, prompts, and workspace content into summaries, drafts, answer...
Freemium
Free plan API
Micro Agent provides AI-assisted capabilities for modern software development workflows.
Freemium
Free plan API Open source
Mistral Le Chat helps users with Mistral assistant through an interactive AI chat experience.
Freemium
Free plan API
Nomi provides conversational AI assistance for users who want interactive answers, follow-ups and task-focused...
Freemium
Free plan API
Paperguide helps researchers work with source material, analyze information, and organize research tasks in a...
Freemium
Free plan API
Perplexica provides conversational AI assistance for users who want interactive answers, follow-ups and task-f...
Freemium
Free plan API
PlayAI provides voice agents for creators, businesses, educators, and developers who need practical audio work...
Freemium
Free plan API
RapidAPI helps developers api marketplace and development platform for discovering, testing, and integrating a...
Freemium
Free plan API
RapidTags helps with youtube tag generation for marketers, creators, site owners and SEO teams.
Freemium
Free plan API
Replit Agent provides AI assistance for software development.
Freemium
Free plan API
What to check before you choose
Having an API is the start of the question rather than the end of it. Rate limits, pricing per call, whether there is a sandbox to develop against, and whether your inputs are retained or used for training all vary enormously, and all of them shape whether a tool is viable at scale. Official API documentation is the only reliable source for those details, and it changes often — treat this list as a way to find the candidates, then verify the specifics with the vendor before you build.
