Changelog

0.4.2 (2026-05-05)

Fixed OpenAI Responses incomplete responses parsing (09a3a2a)
Fixed OpenAI Strict additionalProperties for Responses wire object nesting (c84ad35)
Fixed response_schema check (834de99)
Mapping missing stop reasons for anthropic/bedrock (d3cdfc6)

GitHub Copilot provider with managed token-exchange caching, GHE support, and an escape hatch for pre-exchanged Copilot tokens.
Sycophant.Auth.prepare_credentials_for/2 and the optional prepare_credentials/1 callback on the Sycophant.Auth behaviour.

Add auto_execute_tools option to disable tool auto-execution (053ee00)
Add configurable strict mode for tools (88ef880)
Add support to accumulator in the streams (19a331c)
Added reasoning_budget to the shared params (e568a59)
Map timeout errors to Provider.Timeout and add configurable timeout (a7b9130)
Refactor the reasoning processing (3053590)

Added failed states to streams (7c57f6a)
Fixes the issue when joining multiple system messages (78ec197)
Include error and payload in ResponseValidator JSON parse failure (a011c8e)
Include parameter path in validation error messages (0f34d07)
normalize tool return values before wire encoding (6bb8687)
Propagate reasoning id for OpenAI Responses thinking (17c42c6)
Reasoning budget can be 0 (e482eb8)

add agent mode with GenStateMachine-based conversational agent (fd89593)
Add automatic cost calculation to Usage struct (2c75c58)
Add cost fields to telemetry usage metadata (1106921)
Add finish_reason field with canonical atom mappings across all wire protocols (fa4f770)
add Inspect protocol for all Sycophant structs (2128bdc)
add local provider support via LLMDB auth flag (7c14775)
Add optional OpenTelemetry integration with GenAI semantic conventions (ee8d951)
AWS Bedrock Converse API integration (bfc298d)
Azure AI Foundry provider support (a8c6318)
credentials, transport & pipeline (258d363)
Embedding API with Bedrock Cohere Embed v4 support (692155a)
Extensible registry for auth and wire protocols (5620038)
JSON-serializable structs for conversation persistence (ab6cb7d)
model-first public API with Context as first-class conversation handle (774acd3)
multi-provider wire protocol adapters and recording infrastructure (2ff0c27)
multi-turn conversation support (5ba57a4)
Project Base (b4755f6)
SSE streaming support with recording test infrastructure (1519171)
tools and structured output (c801277)
wire protocol adapters for OpenAI Completions and Responses APIs (f8c4e85)
Wire-specific parameter validation and provider improvements (324d2c7)