LiteAgents 0.3.0a1: harness portability preview

LiteAgents 0.3.0a1 makes the shared profile portable across DeepAgents, Pydantic AI, Claude Agent SDK, Codex, and both OpenCode adapters. Change the harness while keeping your model configuration, application tools, MCP servers, and client code. LiteLLM translates model requests inside the SDK, and compatible native controls remain available through harness_options.

Install this preview with Python 3.11+ (3.12 recommended):

python -m pip install \
  'liteagents[deepagents] @ https://github.com/BerriAI/liteagents/releases/download/v0.3.0a1/liteagents-0.3.0a1-py3-none-any.whl' \
  -c https://github.com/BerriAI/liteagents/releases/download/v0.3.0a1/constraints-tested.txt

A simple agent needs neither Temporal nor PostgreSQL. Replace [deepagents] with [all] to install the other Python harnesses and MCP/Temporal support. OpenCode additionally requires npm install -g opencode-ai@1.18.29. PostgreSQL is a separate postgres extra. Use this GitHub package; the PyPI project named liteagents is a different package.

Repeated query() calls on one client share conversation history in direct and Temporal execution. start_run() creates independent jobs in both modes. Durable follow-ups store immutable history snapshots in SDK storage; Temporal receives a reference. Recorded operations and checkpoints recover after worker loss. Interrupted external effects still require application idempotency. Existing native sessions cannot migrate between harnesses.

Upgrading from 0.2.0: omitted profile.tools now exposes registered application and discovered MCP tools only; select workspace tools explicitly. An empty list disables tools. Direct start_run() jobs no longer share conversation history; use query() for follow-ups. Finish existing durable runs with their original SDK and profile version, and upgrade clients and workers together. See the migration guide.

Getting started · JSON/YAML profiles · Harness-switching cookbook · All cookbooks · Validation

Validation covers six Python/MCP dependency combinations, the native harness/Temporal/PostgreSQL suite, the self-hosted deployment worker image, 23 live-provider checks using one unchanged model alias, all six harness selectors with tools and MCP in direct and Temporal execution, worker-crash recovery, and fresh-wheel examples without Temporal or PostgreSQL installed. SHA256SUMS covers the attached wheel, source distribution, and tested dependency constraints.

Implementation: #9