Source code for ractogateway.anthropic_developer_kit.kit

"""Anthropic Claude Developer Kit — production-grade Claude interface.

Usage::

    from ractogateway import anthropic_developer_kit as anth

    kit = anth.AnthropicDeveloperKit(model="claude-sonnet-4-5-20250929", default_prompt=my_prompt)
    response = kit.chat(anth.ChatConfig(user_message="Hello"))

    for chunk in kit.stream(anth.ChatConfig(user_message="Hello")):
        print(chunk.delta.text, end="", flush=True)

Note: Anthropic does NOT have a native embedding API.  Use OpenAI or
Google kits for embeddings.
"""

from __future__ import annotations

import json as _json
import os
import time
from collections.abc import AsyncIterator, Iterator
from typing import TYPE_CHECKING, Any

from ractogateway._models.chat import ChatConfig
from ractogateway._models.stream import StreamChunk, StreamDelta
from ractogateway._tool_runtime import (
    build_tool_followup_user_message,
    execute_tool_calls_async,
    execute_tool_calls_sync,
)
from ractogateway._validation import (
    async_validate_and_retry,
    validate_and_retry,
    validate_stream_final,
    with_inferred_response_model,
)
from ractogateway.adapters.anthropic_kit import AnthropicLLMKit
from ractogateway.adapters.base import ChatTurn, FinishReason, LLMResponse, ToolCallResult
from ractogateway.exceptions import RactoGatewayError, _wrap_provider_error
from ractogateway.prompts.engine import RactoPrompt

if TYPE_CHECKING:
    from ractogateway.cache.exact_cache import ExactMatchCache
    from ractogateway.cache.semantic_cache import SemanticCache
    from ractogateway.routing.router import CostAwareRouter
    from ractogateway.telemetry.metrics import GatewayMetricsMiddleware
    from ractogateway.telemetry.tracer import RactoTracer
    from ractogateway.truncation.truncator import TokenTruncator


def _require_anthropic() -> Any:
    try:
        import anthropic
    except ImportError as exc:
        raise ImportError(
            "The 'anthropic' package is required for AnthropicDeveloperKit. "
            "Install it with:  pip install ractogateway[anthropic]"
        ) from exc
    return anthropic


[docs] class AnthropicDeveloperKit: """Complete Anthropic Claude developer kit — chat, streaming, and optional performance/cost optimisation middleware. Parameters ---------- model: Claude model (e.g. ``"claude-sonnet-4-5-20250929"``, ``"claude-opus-4-6"``). Use ``"auto"`` when a :class:`~ractogateway.routing.CostAwareRouter` is provided — the router will select the model per-request. api_key: Anthropic API key. Falls back to ``ANTHROPIC_API_KEY`` env var. default_prompt: RACTO prompt used when ``ChatConfig.prompt`` is ``None``. exact_cache: Optional :class:`~ractogateway.cache.ExactMatchCache`. semantic_cache: Optional :class:`~ractogateway.cache.SemanticCache`. router: Optional :class:`~ractogateway.routing.CostAwareRouter`. **Required** when ``model="auto"``. truncator: Optional :class:`~ractogateway.truncation.TokenTruncator`. tracer: Optional :class:`~ractogateway.telemetry.RactoTracer`. Emits OpenTelemetry spans for every chat and stream call. Requires ``pip install ractogateway[telemetry]``. metrics: Optional :class:`~ractogateway.telemetry.GatewayMetricsMiddleware`. Records Prometheus metrics (latency, tokens, cost, cache hit/miss). Requires ``pip install ractogateway[prometheus]``. """ provider: str = "anthropic" def __init__( self, model: str = "claude-sonnet-4-5-20250929", *, api_key: str | None = None, default_prompt: RactoPrompt | None = None, exact_cache: ExactMatchCache | None = None, semantic_cache: SemanticCache | None = None, router: CostAwareRouter | None = None, truncator: TokenTruncator | None = None, tracer: RactoTracer | None = None, metrics: GatewayMetricsMiddleware | None = None, ) -> None: if model == "auto" and router is None: raise ValueError( "model='auto' requires a CostAwareRouter. " "Pass router=CostAwareRouter([...]) to the kit." ) self._model = model self._api_key = api_key self._default_prompt = default_prompt self._exact_cache = exact_cache self._semantic_cache = semantic_cache self._router = router self._truncator = truncator self._tracer = tracer self._metrics = metrics # Adapter pool for cost-aware routing self._adapters: dict[str, AnthropicLLMKit] = {} fallback = "claude-haiku-4-5-20251001" self._adapter = self._get_adapter(model if model != "auto" else fallback) # ------------------------------------------------------------------ # Adapter pool # ------------------------------------------------------------------ def _get_adapter(self, model: str) -> AnthropicLLMKit: """Return (or lazily create) an adapter for *model*.""" if model not in self._adapters: self._adapters[model] = AnthropicLLMKit(model=model, api_key=self._api_key) return self._adapters[model] # ------------------------------------------------------------------ # Client factories # ------------------------------------------------------------------ def _sync_client(self) -> Any: anthropic = _require_anthropic() key = self._api_key or os.environ.get("ANTHROPIC_API_KEY") kw: dict[str, Any] = {"api_key": key} if key else {} return anthropic.Anthropic(**kw) def _async_client(self) -> Any: anthropic = _require_anthropic() key = self._api_key or os.environ.get("ANTHROPIC_API_KEY") kw: dict[str, Any] = {"api_key": key} if key else {} return anthropic.AsyncAnthropic(**kw) def _resolve_prompt(self, config: ChatConfig) -> RactoPrompt: if not isinstance(config, ChatConfig): raise TypeError( f"chat() expects a ChatConfig object, got {type(config).__name__!r}. " "Example: kit.chat(ChatConfig(user_message='Hello'))" ) prompt = config.prompt or self._default_prompt if prompt is None: return RactoPrompt( role="You are a helpful AI assistant.", aim="Answer the user's question accurately and helpfully.", constraints=["Be accurate, clear, and concise."], tone="Helpful and professional.", output_format="text", ) return prompt # ------------------------------------------------------------------ # Middleware helpers # ------------------------------------------------------------------ def _resolve_model(self, user_message: str) -> str: if self._router is not None: return self._router.route(user_message) return self._model def _apply_truncation(self, config: ChatConfig, model: str) -> ChatConfig: if self._truncator is None: return config return self._truncator.truncate(config, model) # ------------------------------------------------------------------ # Chat (sync / async) # ------------------------------------------------------------------
[docs] def chat(self, config: ChatConfig) -> LLMResponse: """Synchronous chat completion with optional middleware pipeline. Middleware order: truncate → exact cache → semantic cache → route model → API call → write caches → record telemetry. """ t0 = time.perf_counter() prompt = self._resolve_prompt(config) if config.chain_of_thought: from ractogateway._cot import apply_chain_of_thought prompt = apply_chain_of_thought(prompt) model = self._resolve_model(config.user_message) config = self._apply_truncation(config, model) validation_config = with_inferred_response_model(config, prompt) system_prompt = prompt.compile() # Exact-match cache lookup if self._exact_cache is not None: cached = self._exact_cache.get( config.user_message, system_prompt, model, config.temperature, config.max_tokens, ) if cached is not None: _lat = (time.perf_counter() - t0) * 1000 if self._metrics is not None: self._metrics.record_cache_hit("exact") if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, cache_hit="exact" ) return cached # Semantic cache lookup if self._semantic_cache is not None: sem_cached = self._semantic_cache.get(config.user_message) if sem_cached is not None: _lat = (time.perf_counter() - t0) * 1000 if self._metrics is not None: self._metrics.record_cache_hit("semantic") if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, cache_hit="semantic", ) return sem_cached # Record cache misses for each checked cache if self._metrics is not None: if self._exact_cache is not None: self._metrics.record_cache_miss("exact") if self._semantic_cache is not None: self._metrics.record_cache_miss("semantic") # API call adapter = self._get_adapter(model) original_user_message = config.user_message history_turns: list[ChatTurn] | None = ( [ChatTurn(role=m.role.value, content=m.content) for m in config.history] if config.history else None ) def _run_validated(user_message: str) -> LLMResponse: raw = adapter.run( prompt, user_message, history=history_turns, tools=config.tools, temperature=config.temperature, max_tokens=config.max_tokens, attachments=config.attachments, native_thinking=config.native_thinking, thinking_budget=config.thinking_budget, **config.extra, ) return validate_and_retry( raw, validation_config, adapter_run=lambda msg: adapter.run( prompt, msg, history=history_turns, tools=config.tools, temperature=config.temperature, max_tokens=config.max_tokens, **config.extra, ), ) try: response = _run_validated(config.user_message) if config.auto_execute_tools and config.tools is not None: for _ in range(config.max_tool_turns): if ( response.finish_reason is not FinishReason.TOOL_CALL or not response.tool_calls ): break results = execute_tool_calls_sync(response.tool_calls, config.tools) follow_up_message = build_tool_followup_user_message( original_user_message=original_user_message, tool_calls=response.tool_calls, results=results, ) response = _run_validated(follow_up_message) # Write to caches if self._exact_cache is not None: self._exact_cache.put( config.user_message, system_prompt, model, config.temperature, config.max_tokens, response, ) if self._semantic_cache is not None: self._semantic_cache.put(config.user_message, response) # Record telemetry _lat = (time.perf_counter() - t0) * 1000 _in = response.usage.get("prompt_tokens", 0) if response.usage else 0 _out = response.usage.get("completion_tokens", 0) if response.usage else 0 _tcs = response.tool_calls or [] if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, input_tokens=_in, output_tokens=_out, tool_calls=len(_tcs), ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="chat", status="ok", latency_s=_lat / 1000, input_tokens=_in, output_tokens=_out, tool_calls=_tcs, ) return response except Exception as _exc: _lat = (time.perf_counter() - t0) * 1000 _etype = type(_exc).__name__ if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, status="error", error_type=_etype, ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="chat", status="error", latency_s=_lat / 1000, ) raise
[docs] async def achat(self, config: ChatConfig) -> LLMResponse: """Async chat completion with optional middleware pipeline.""" t0 = time.perf_counter() prompt = self._resolve_prompt(config) if config.chain_of_thought: from ractogateway._cot import apply_chain_of_thought prompt = apply_chain_of_thought(prompt) model = self._resolve_model(config.user_message) config = self._apply_truncation(config, model) validation_config = with_inferred_response_model(config, prompt) system_prompt = prompt.compile() # Exact-match cache lookup if self._exact_cache is not None: cached = self._exact_cache.get( config.user_message, system_prompt, model, config.temperature, config.max_tokens, ) if cached is not None: _lat = (time.perf_counter() - t0) * 1000 if self._metrics is not None: self._metrics.record_cache_hit("exact") if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, cache_hit="exact" ) return cached # Semantic cache lookup if self._semantic_cache is not None: sem_cached = self._semantic_cache.get(config.user_message) if sem_cached is not None: _lat = (time.perf_counter() - t0) * 1000 if self._metrics is not None: self._metrics.record_cache_hit("semantic") if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, cache_hit="semantic", ) return sem_cached if self._metrics is not None: if self._exact_cache is not None: self._metrics.record_cache_miss("exact") if self._semantic_cache is not None: self._metrics.record_cache_miss("semantic") # API call adapter = self._get_adapter(model) original_user_message = config.user_message history_turns: list[ChatTurn] | None = ( [ChatTurn(role=m.role.value, content=m.content) for m in config.history] if config.history else None ) async def _arun_validated(user_message: str) -> LLMResponse: raw = await adapter.arun( prompt, user_message, history=history_turns, tools=config.tools, temperature=config.temperature, max_tokens=config.max_tokens, attachments=config.attachments, native_thinking=config.native_thinking, thinking_budget=config.thinking_budget, **config.extra, ) return await async_validate_and_retry( raw, validation_config, adapter_arun=lambda msg: adapter.arun( prompt, msg, history=history_turns, tools=config.tools, temperature=config.temperature, max_tokens=config.max_tokens, **config.extra, ), ) try: response = await _arun_validated(config.user_message) if config.auto_execute_tools and config.tools is not None: for _ in range(config.max_tool_turns): if ( response.finish_reason is not FinishReason.TOOL_CALL or not response.tool_calls ): break results = await execute_tool_calls_async( response.tool_calls, config.tools, ) follow_up_message = build_tool_followup_user_message( original_user_message=original_user_message, tool_calls=response.tool_calls, results=results, ) response = await _arun_validated(follow_up_message) # Write to caches if self._exact_cache is not None: self._exact_cache.put( config.user_message, system_prompt, model, config.temperature, config.max_tokens, response, ) if self._semantic_cache is not None: self._semantic_cache.put(config.user_message, response) _lat = (time.perf_counter() - t0) * 1000 _in = response.usage.get("prompt_tokens", 0) if response.usage else 0 _out = response.usage.get("completion_tokens", 0) if response.usage else 0 _tcs = response.tool_calls or [] if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, input_tokens=_in, output_tokens=_out, tool_calls=len(_tcs), ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="chat", status="ok", latency_s=_lat / 1000, input_tokens=_in, output_tokens=_out, tool_calls=_tcs, ) return response except Exception as _exc: _lat = (time.perf_counter() - t0) * 1000 _etype = type(_exc).__name__ if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, status="error", error_type=_etype, ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="chat", status="error", latency_s=_lat / 1000, ) raise
# ------------------------------------------------------------------ # Stream (sync / async) # ------------------------------------------------------------------
[docs] def stream(self, config: ChatConfig) -> Iterator[StreamChunk]: """Synchronous streaming via Anthropic's ``messages.stream()``. Example:: for chunk in kit.stream(config): print(chunk.delta.text, end="", flush=True) if chunk.is_final: print(f"\\nTokens: {chunk.usage}") """ t0 = time.perf_counter() prompt = self._resolve_prompt(config) if config.chain_of_thought: from ractogateway._cot import apply_chain_of_thought prompt = apply_chain_of_thought(prompt) model = self._resolve_model(config.user_message) config = self._apply_truncation(config, model) validation_config = with_inferred_response_model(config, prompt) adapter = self._get_adapter(model) client = self._sync_client() history_turns: list[ChatTurn] | None = ( [ChatTurn(role=m.role.value, content=m.content) for m in config.history] if config.history else None ) request = adapter._build_request( prompt, config.user_message, history=history_turns, tools=config.tools, temperature=config.temperature, max_tokens=config.max_tokens, attachments=config.attachments, native_thinking=config.native_thinking, thinking_budget=config.thinking_budget, **config.extra, ) accumulated = "" accumulated_thinking = "" tc_acc: dict[int, dict[str, Any]] = {} thinking_indices: set[int] = set() finish_reason = FinishReason.STOP usage: dict[str, int] = {} _span_recorded = False try: with client.messages.stream(**request) as stream_resp: for event in stream_resp: chunk = self._process_anthropic_event( event, accumulated, accumulated_thinking, tc_acc, thinking_indices, finish_reason, usage, ) if chunk is not None: accumulated = chunk.accumulated_text accumulated_thinking = chunk.accumulated_thinking if chunk.finish_reason is not None: finish_reason = chunk.finish_reason if chunk.usage: usage = chunk.usage if chunk.is_final and validation_config.response_model is not None: chunk.parsed = validate_stream_final( chunk.accumulated_text, validation_config ) if chunk.is_final and not _span_recorded: _span_recorded = True _lat = (time.perf_counter() - t0) * 1000 _in = chunk.usage.get("prompt_tokens", 0) if chunk.usage else 0 _out = chunk.usage.get("completion_tokens", 0) if chunk.usage else 0 _tcs = chunk.tool_calls or [] if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, input_tokens=_in, output_tokens=_out, tool_calls=len(_tcs), ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="stream", status="ok", latency_s=_lat / 1000, input_tokens=_in, output_tokens=_out, tool_calls=_tcs, ) yield chunk except RactoGatewayError: if not _span_recorded: _lat = (time.perf_counter() - t0) * 1000 if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, status="error", error_type="RactoGatewayError", ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="stream", status="error", latency_s=(time.perf_counter() - t0), ) raise except Exception as exc: if not _span_recorded: _lat = (time.perf_counter() - t0) * 1000 if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, status="error", error_type=type(exc).__name__, ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="stream", status="error", latency_s=(time.perf_counter() - t0), ) raise _wrap_provider_error(exc, "anthropic") from exc
[docs] async def astream(self, config: ChatConfig) -> AsyncIterator[StreamChunk]: """Async streaming via Anthropic's async ``messages.stream()``.""" t0 = time.perf_counter() prompt = self._resolve_prompt(config) if config.chain_of_thought: from ractogateway._cot import apply_chain_of_thought prompt = apply_chain_of_thought(prompt) model = self._resolve_model(config.user_message) config = self._apply_truncation(config, model) validation_config = with_inferred_response_model(config, prompt) adapter = self._get_adapter(model) client = self._async_client() history_turns: list[ChatTurn] | None = ( [ChatTurn(role=m.role.value, content=m.content) for m in config.history] if config.history else None ) request = adapter._build_request( prompt, config.user_message, history=history_turns, tools=config.tools, temperature=config.temperature, max_tokens=config.max_tokens, attachments=config.attachments, native_thinking=config.native_thinking, thinking_budget=config.thinking_budget, **config.extra, ) accumulated = "" accumulated_thinking = "" tc_acc: dict[int, dict[str, Any]] = {} thinking_indices: set[int] = set() finish_reason = FinishReason.STOP usage: dict[str, int] = {} _span_recorded = False try: async with client.messages.stream(**request) as stream_resp: async for event in stream_resp: chunk = self._process_anthropic_event( event, accumulated, accumulated_thinking, tc_acc, thinking_indices, finish_reason, usage, ) if chunk is not None: accumulated = chunk.accumulated_text accumulated_thinking = chunk.accumulated_thinking if chunk.finish_reason is not None: finish_reason = chunk.finish_reason if chunk.usage: usage = chunk.usage if chunk.is_final and validation_config.response_model is not None: chunk.parsed = validate_stream_final( chunk.accumulated_text, validation_config ) if chunk.is_final and not _span_recorded: _span_recorded = True _lat = (time.perf_counter() - t0) * 1000 _in = chunk.usage.get("prompt_tokens", 0) if chunk.usage else 0 _out = chunk.usage.get("completion_tokens", 0) if chunk.usage else 0 _tcs = chunk.tool_calls or [] if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, input_tokens=_in, output_tokens=_out, tool_calls=len(_tcs), ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="stream", status="ok", latency_s=_lat / 1000, input_tokens=_in, output_tokens=_out, tool_calls=_tcs, ) yield chunk except RactoGatewayError: if not _span_recorded: _lat = (time.perf_counter() - t0) * 1000 if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, status="error", error_type="RactoGatewayError", ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="stream", status="error", latency_s=(time.perf_counter() - t0), ) raise except Exception as exc: if not _span_recorded: _lat = (time.perf_counter() - t0) * 1000 if self._tracer is not None: self._tracer.record_chat_span( provider=self.provider, model=model, latency_ms=_lat, status="error", error_type=type(exc).__name__, ) if self._metrics is not None: self._metrics.record_request( provider=self.provider, model=model, operation="stream", status="error", latency_s=(time.perf_counter() - t0), ) raise _wrap_provider_error(exc, "anthropic") from exc
# ------------------------------------------------------------------ # Internal — Anthropic stream event processing # ------------------------------------------------------------------ @staticmethod def _process_anthropic_event( event: Any, accumulated: str, accumulated_thinking: str, tc_acc: dict[int, dict[str, Any]], thinking_indices: set[int], finish_reason: FinishReason, usage: dict[str, int], ) -> StreamChunk | None: etype = event.type if etype == "content_block_start": block = event.content_block if block.type == "thinking": thinking_indices.add(event.index) elif block.type == "tool_use": tc_acc[event.index] = { "id": block.id, "name": block.name, "args": "", } return StreamChunk( accumulated_text=accumulated, accumulated_thinking=accumulated_thinking, raw=event, ) if etype == "content_block_delta": delta = event.delta if delta.type == "thinking_delta": thinking_text = delta.thinking accumulated_thinking += thinking_text return StreamChunk( delta=StreamDelta(thinking=thinking_text), accumulated_text=accumulated, accumulated_thinking=accumulated_thinking, is_thinking=True, raw=event, ) if delta.type == "text_delta": text = delta.text accumulated += text return StreamChunk( delta=StreamDelta(text=text), accumulated_text=accumulated, accumulated_thinking=accumulated_thinking, raw=event, ) if delta.type == "input_json_delta": idx = event.index if idx in tc_acc: tc_acc[idx]["args"] += delta.partial_json return StreamChunk( delta=StreamDelta( tool_call_args_fragment=delta.partial_json, ), accumulated_text=accumulated, accumulated_thinking=accumulated_thinking, raw=event, ) return None if etype == "message_delta": stop_reason = getattr(event.delta, "stop_reason", None) fr = AnthropicLLMKit._map_finish_reason(stop_reason) u: dict[str, int] = {} if hasattr(event, "usage") and event.usage: inp = getattr(event.usage, "input_tokens", 0) or 0 out = getattr(event.usage, "output_tokens", 0) or 0 u = { "prompt_tokens": inp, "completion_tokens": out, "total_tokens": inp + out, } return StreamChunk( accumulated_text=accumulated, accumulated_thinking=accumulated_thinking, finish_reason=fr, usage=u, raw=event, ) if etype == "message_stop": return StreamChunk( accumulated_text=accumulated, accumulated_thinking=accumulated_thinking, finish_reason=finish_reason, tool_calls=_flush_tool_calls(tc_acc), usage=usage, is_final=True, raw=event, ) return None
# ====================================================================== # Module-level helpers # ====================================================================== def _flush_tool_calls(acc: dict[int, dict[str, Any]]) -> list[ToolCallResult]: results: list[ToolCallResult] = [] for entry in acc.values(): try: args = _json.loads(entry["args"]) if entry["args"] else {} except _json.JSONDecodeError: args = {"_raw": entry["args"]} results.append( ToolCallResult(id=entry["id"], name=entry["name"], arguments=args), ) return results