pi-python v0.1.0

Initial public release.

Added

pi-agent-core

• Core runtime (Phase 1): Agent with steering/follow-up queues, abort, subscribe() event barrier; agent_loop with pi-compatible event protocol, parallel/sequential tool execution, terminate semantics.
• LangChain adapter: StreamFn over astream() for OpenAI / Anthropic / DeepSeek / any init_chat_model provider; mock stream for tests (no API keys needed).
• Production hardening (Phase 2/2.5):
  • Cross-provider message replay (transform_messages: tool-call id normalization, thinking downgrade, image stripping).
  • Usage & cost tracking with CostCalculator.
  • Thinking/reasoning: provider param mapping, streamed thinking_delta events, Anthropic signature replay, DeepSeek-style reasoning_content.
  • Stream-level retries with exponential backoff + jitter, Retry-After aware.
  • Runaway protection: max_turns / tool_timeout.
  • Guardrail hooks: before_llm_call (with ContextBudget), after_llm_call, on_agent_end.
  • Observability: on_payload / on_response hooks; run_id / turn_id on every event.
  • Granular stream events: text_start/end, thinking_start/end, toolcall_start/end.
  • Structured output: response_schema (Pydantic model or JSON schema).
  • Tool-result images: Anthropic native blocks, user-message fallback elsewhere.
  • OpenAI-compatible gateways via Model.base_url.
• Tool ecosystem (P6):
  • 7 built-in coding tools: read, bash, edit, write, grep, find, ls.
  • Group factories: create_coding_tools() / create_read_only_tools().
  • LangChain BaseTool → AgentTool adapter (from_langchain_tool).

pi-agent-harness

• Session tree (H1): SessionRepo with filesystem storage, uuid7 IDs, branch/fork semantics, message append/list.
• AgentHarness runtime (H2): orchestration layer over Agent, queue rollback, abort aggregation, event-based idle wait.
• Compaction & tree navigation (H3): token-based compaction with branch summaries, navigate_tree for branch exploration.
• Skills, templates & env (H4): skill discovery, prompt templates, system prompt injection, LocalExecutionEnv for sandboxed execution.