package ai-sdk-react

  1. Overview
  2. Docs
Melange bindings for @ai-sdk/react

Install 

dune-project
 Dependency

github.com Readme Changelog Edit opam file Versions (3)

Authors

  1. A
    Ahrefs

Maintainers

  1. J
    José Nogueira <jose.nogueira@ahrefs.com>

Sources

ocaml-ai-sdk-0.2.tbz
sha256=17063971a74ccd72619a43ecfcb29d28cdf08f90d406a960bd475f65fee1a0d9
sha512=1f3f2d1d7fa4f53843cc1b303cbf9d6dcc85780e7c768ced723f3de83ea897748fa231b48e729216abcc069dee818edc6751a45271541e8a007369bf6e9d23e3

doc/README.html

ocaml-ai-sdk

Type-safe, provider-agnostic AI model abstraction for OCaml, inspired by the Vercel AI SDK. Targets wire compatibility with AI SDK v6 so you can pair an OCaml backend with @ai-sdk/react frontends.

Libraries

Library

opam lib

Description

ai_provider

ocaml-ai-sdk.ai_provider

Provider abstraction — language model module types, tool definitions, prompt types, GADT-based provider options

ai_provider_anthropic

ocaml-ai-sdk.ai_provider_anthropic

Anthropic Messages API — streaming SSE, thinking, cache control, full Claude model catalog

ai_provider_openai

ocaml-ai-sdk.ai_provider_openai

OpenAI Chat Completions API — streaming SSE, tool calling with strict mode, GPT-4o/o1/o3/o4-mini catalog

ai_core

ocaml-ai-sdk.ai_core

Core SDK — generate_text, stream_text (with tool loops), UIMessage stream protocol, server handler, structured output

ai_sdk_react

ai-sdk-react.ai_sdk_react

Melange bindings for @ai-sdk/react — useChat, useCompletion, v6 part types

Quick start

opam install ocaml-ai-sdk

One-shot generation

open Ai_core
open Ai_provider_anthropic

let () =
  Lwt_main.run @@
  let model = Anthropic.create_model "claude-sonnet-4-20250514" in
  let%lwt result = Generate_text.generate ~model ~prompt:"Say hello" () in
  Lwt_io.printl result.text

Streaming

let () =
  Lwt_main.run @@
  let model = Anthropic.create_model "claude-sonnet-4-20250514" in
  let%lwt result = Stream_text.stream ~model ~prompt:"Tell me a joke" () in
  Lwt_stream.iter_s Lwt_io.printl result.text_stream

Chat server (with UIMessage protocol)

let handler = Server_handler.create ~model ()
(* Serves SSE responses compatible with useChat() from @ai-sdk/react *)

See examples/ for complete runnable demos including tool use, thinking, structured output, and full-stack Melange apps.

Architecture

ai_provider          Provider abstraction (module types, GADT options)
├── ai_provider_anthropic   Anthropic implementation
├── ai_provider_openai      OpenAI implementation
└── ai_core                 Core SDK (generate, stream, UIMessage protocol)

Key design choices:

  • Provider options use an extensible GADT (type _ key = ..) for compile-time type-safe provider-specific settings (e.g. thinking budget, cache control)
  • Prompt types are role-constrained variants — System accepts only strings, User accepts text + files, etc.
  • Streaming uses Lwt_stream.t — stream_text returns synchronously with streams populated by a background Lwt task
  • UIMessage protocol emits SSE chunks matching the ai@6 Zod schemas exactly, so useChat() works without adaptation

AI SDK v6 compatibility

The UIMessage stream protocol (x-vercel-ai-ui-message-stream: v1) is wire-compatible with:

  • @ai-sdk/react 3.x (useChat, useCompletion)
  • ai 6.x (core SDK)

All chunk types are supported: text, reasoning, tool call (start/delta/result), source, file, data, error, finish message/step.

Requirements

  • OCaml >= 4.14
  • For Melange bindings: melange >= 4.0.0

Development

make build    # Build all libraries
make test     # Run test suites
make dev      # Watch mode

License

MIT