All notable changes to this project will be documented in this file.
ai_provider_anthropic)Object_json mode now uses Anthropic's native output_config.format = { type: "json_schema", schema } field on capable models (Haiku 4.5, Sonnet 4.5/4.6, Opus 4.5/4.6/4.7), matching upstream @ai-sdk/anthropic. Schema enforcement is handled by the provider, not by appending instructions to the system prompt.Custom model ids, the provider synthesises a tool named json carrying the schema as input_schema and forces tool_choice = { type: "tool", name: "json" }. The caller's system prompt is left untouched.Object_json None (no schema) now receive an Unsupported_feature warning because Anthropic cannot enforce JSON without a schema.Claude_opus_4_7. The supports_structured_output capability flag is now accurate per model (previously defaulted to true for all known models).ai_core)Output.parse_output — when a step has no assistant text, falls back to decoding the json tool call's args. Enables end-to-end structured output on the Anthropic fallback path and on any future provider that adopts the same convention.Stream_text — Tool_call_delta events for the json tool drive the partial-output parser, so streaming callers see incremental JSON on the fallback path with the same UX as the native path.ai_provider)Ai_provider.Http_timeouts module and Ai_provider.Http_client wrapper. Defaults: 600s for response headers (request_timeout) and 300s for silence between streaming chunks (stream_idle_timeout). Override per-provider via Config.create ?timeouts. Conservative values chosen to catch stuck connections and bugs, not bound legitimate workloads — a 20-minute streaming response completes fine as long as chunks keep flowing.Provider_error.Timeout kind with phase (Request_headers | Stream_idle), elapsed_s, and limit_s. is_retryable is derived: Stream_idle is retryable (connection is dead); Request_headers is not (server may already be processing the request).Sse.parse_events no longer hangs consumers on upstream errors. Previously, an exception from the upstream line stream left the output stream pending forever. It now closes cleanly (via push None) and re-raises to Lwt.async_exception_hook so the underlying bug stays visible.Mode.fallback_json_tool_name — exported constant ("json") naming the synthetic tool used by the structured-output tool-use fallback convention. Shared between ai_core and providers so the convention has a single source of truth.ai_provider_openai, ai_provider_anthropic, ai_provider_openrouter)Config.t gains a timeouts : Http_timeouts.t field. All HTTP traffic now routes through Http_client, removing three copies of the unguarded body_to_line_stream helper.structured_output — live-API smoke test exercising both the native and tool-fallback paths with ppx_deriving_jsonschema for schema derivation and melange-json-native's of_json deriver for typed response decoding.ai_core)Smooth_stream — stream transformer that buffers Text_delta and Reasoning_delta chunks and re-emits them in controlled pieces with configurable inter-chunk delays. Five chunking modes: Word (default), Line, Regex (custom Re2 pattern), Segmenter (Unicode UAX#29 word boundaries via uuseg, recommended for CJK), and Custom (user function). Matches the upstream AI SDK's smoothStream transform.?transform parameter on stream_text and server_handler.handle_chat — generic stream transformer (Text_stream_part.t Lwt_stream.t -> Text_stream_part.t Lwt_stream.t) applied between the raw event stream and consumer-facing streams. Both full_stream and text_stream reflect the transformed output.Retry module with jitter, configurable initial delay and backoff factor, and parameter validation. ?max_retries threaded through generate_text, stream_text, and server_handler.handle_chat. Retries only on errors marked retryable.Telemetry module with OpenTelemetry-compatible span instrumentation via the trace library (ocaml-trace). Configurable Telemetry.t settings control enable/disable, input/output recording privacy, function ID, custom metadata, and lifecycle integration callbacks (on_start, on_step_finish, on_tool_call_start, on_tool_call_finish, on_finish). Span hierarchy matches upstream AI SDK: ai.generateText / ai.streamText root spans, *.doGenerate / *.doStream step spans, and ai.toolCall tool execution spans. ?telemetry parameter threaded through generate_text, stream_text, and server_handler.handle_chat.ai_provider)is_retryable field on Provider_error.t — defaults from HTTP status code (429, 5xx are retryable). Anthropic and OpenAI providers set it explicitly based on error classification.smooth_streaming — demonstrates all five chunking modestelemetry_logging — demonstrates integration callbacks for lifecycle loggingre2 (>= 0.16) and uuseg (>= 17.0) to ai_coretrace (>= 0.12) to ai_coreInitial release of the OCaml AI SDK — a type-safe, provider-agnostic AI model abstraction inspired by the Vercel AI SDK, targeting AI SDK v6 wire compatibility.
ai_provider)Provider_options for compile-time type-safe provider-specific settingsPrompt types (System = string only, User = text + files, etc.)Language_model.S module type with first-class module wrapperTool, Tool_choice, Mode, Content foundation typesFinish_reason, Usage, Warning, Provider_error typesProvider.S and Middleware.S module type signaturesCall_options, Generate_result, Stream_part, Stream_result typesai_provider_anthropic)Thinking support with budget_tokens smart constructor (>= 1024)Cache_control for prompt cachingAnthropic_options via the extensible GADT systemmax_tokensai_provider_openai)ai_core)generate_text — synchronous text generation with multi-step tool loopstream_text — streaming text generation with multi-step tool loop, returns synchronously with streams filled by background Lwt taskOutput.text, Output.object_, Output.enum, Output.array, Output.choice with JSON Schema validationdata: {json}\n\n encoding with x-vercel-ai-ui-message-stream: v1 header, all v6 chunk typesUi_message_stream_writer — composable stream builder with write (synchronous) and merge (non-blocking via Lwt.async), lifecycle management, ref-counted in-flight merge tracking, on_finish callbackneeds_approval predicate on Core_tool.t, step loop partitioning, Tool_approval_request chunk type, stateless re-submission with approved_tool_call_idsStop_condition — step loop termination predicates matching upstream stopWhen: step_count_is, has_tool_call, is_met (OR semantics with short-circuit); wired through generate_text, stream_text, and server_handler; max_steps remains as independent hard safety capai-sdk-react)useChat and useCompletion hook bindings for @ai-sdk/reactdata_ui_partclassify function for part type dispatchone_shot, streaming, tool_use, thinking, generate, stream_chat, agent_loop — standalone CLI exampleschat_server — cohttp chat server with React frontend, tool approval, structured outputcustom_stream — custom data streaming with Melange frontendai-e2e — end-to-end Melange app with 11 demos (basic chat, reasoning, tool use, tool approval, client tools, file attachments, structured output, completion, web search, retry/regenerate)generate_opam_files for automated opam file generationmlx-pp / ocamlformat-mlx)