Changelog

All notable changes to Attest are documented here. Versions follow Semantic Versioning.

v0.4.2 — 2026-02-22

SDK patch release — adapter fixes and async compatibility

Fixes

LangChain adapter — Add missing callback protocol attributes (ignore_agent, ignore_retry, raise_error) required by LangChain’s BaseCallbackHandler interface. Handle LangGraph AIMessage and ToolMessage output formats so traces capture tool-call responses correctly.
expect() DSL — Accept Trace directly in addition to AgentResult. Auto-wraps into AgentResult for manual adapter workflows that build traces via TraceBuilder without going through a provider adapter.
Plugin fixture — Run the engine event loop in a background daemon thread with run_coroutine_threadsafe() bridge. Fixes Future attached to a different loop errors when pytest-asyncio tests (e.g., google-adk) call into the engine from a separate event loop.

Upgrade

uv add attest-ai@latest

Notes

No engine changes. The Go engine binary remains at v0.4.0. ENGINE_VERSION is unchanged; auto-download continues to fetch v0.4.0 binaries.

v0.4.1 — 2026-02-21

SDK patch release — engine auto-download

Features

Engine auto-download — Both Python and TypeScript SDKs now automatically download the attest-engine binary from GitHub Releases on first use. No manual binary setup required after uv add attest-ai or pnpm add @attest-ai/core.
SHA256 verification — Downloaded binaries are verified against checksums-sha256.txt from the release. Checksum mismatch aborts the download with a clear error.
Version-pinned cache — Binaries are cached at ~/.attest/bin/ with a .engine-version marker. SDK version mismatch triggers automatic re-download.

Discovery chain — Engine binary resolution follows a predictable order:

ATTEST_ENGINE_PATH env var
  → PATH lookup
  → ~/.attest/bin/ (shared cache, version-checked)
  → ../../bin/ (monorepo dev layout)
  → ./bin/ (local)
  → auto-download from GitHub Releases
  → actionable error message

Opt-out — Set ATTEST_ENGINE_NO_DOWNLOAD=1 to disable network access. The error message explains alternative installation methods.

Fixes

pytest plugin — pytest.skip() replaced with pytest.fail() when the engine binary is missing. With auto-download in place, silent skipping is no longer appropriate; real errors are now surfaced.
TypeScript VERSION — Corrected from 0.3.0 to 0.4.1.

Other

Examples moved — All example projects relocated to attest-framework/attest-examples for independent versioning. A redirect README remains in the main repo.

Install / Upgrade

Python

uv add attest-ai

TypeScript

pnpm add @attest-ai/core

Environment Variables

Variable	Purpose	Default
`ATTEST_ENGINE_PATH`	Absolute path to engine binary — skips all discovery	unset
`ATTEST_ENGINE_NO_DOWNLOAD`	`1` / `true` / `yes` disables auto-download	unset (enabled)

v0.4.0 — 2026-02-20

Production & Polish

Result history with SQLite storage
Drift detection (σ-based statistical thresholds)
Continuous eval runner with sampling and alerting
Plugin system (attest.plugins entry point group)
CrewAI adapter (11 adapters total)
CLI init and validate commands
MkDocs documentation site

v0.3.0 — 2026-02-20

Simulation & Multi-Agent

Layers 7-8: simulation runtime, multi-agent testing
TypeScript SDK (first npm publish: @attest-ai/core, @attest-ai/vitest)
Framework adapters: LangChain, Google ADK, LlamaIndex

v0.2.0 — 2026-02-19

Semantic & Judge Layers

Layers 5-6: ONNX local embeddings, LLM-as-judge
Soft failure support
OTel adapter
setup-attest GitHub Action

v0.1.0

Foundation

Layers 1-4: schema validation, cost/performance, trace structure, content validation
Python SDK with pytest plugin
4 provider adapters: OpenAI, Anthropic, Gemini, Ollama
PyPI + GitHub release