petfishframework 0.1.2

petfishFramework — a general AI Agent framework

petfishFramework

The AI agent framework where reliability is architecture, not an afterthought.

Why petfishFramework?

Every agent framework lets you call tools. Most let you plug in RAG. But none treat reliability as a structural property of the framework itself — they bolt it on after.

petfishFramework is built around three insights validated by academic research:

1. Reliability is architectural — the same model scores 30+ points differently depending on the agent scaffold (GAIA benchmark). Framework quality IS product quality.
2. MCP is the standard — Model Context Protocol is now universal. We make it the canonical tool contract, not an adapter.
3. Reasoning strategies are pluggable — ReAct is just one option. Tree-of-Thoughts (18× improvement on some tasks), LATS (MCTS for agents), and LLM+P (symbolic planning) are first-class.

Comparison

Dimension	LangChain	CrewAI	petfishFramework
Reliability metric	Manual (LangSmith)	None	Pass^k built-in (freeze+perturb)
Reasoning strategies	ReAct only	ReAct only	ReAct + LATS + LLM+P
MCP support	Adapter	Adapter	Canonical tool contract + real stdio
Cost control	Logging	None	Hard budget enforcement
Multi-agent	Manual chains	Role-based crews	Agent-as-Tool (through chokepoint)
Permissions	None	None	SARC model + 6 DecisionEffects
Replay/audit	External	None	Event-sourced (AUDIT/RESUME/RERUN)
Async	Partial	No	Dual interface (sync + async)
Streaming	Yes	No	Yes
License	MIT	MIT	MIT

Quick Start

pip install petfishframework

from petfishframework import Agent, ReAct
from petfishframework.tools.calculator import Calculator

agent = Agent(
    model="openai:gpt-4o",  # or OpenAIModel(model="gpt-4o")
    reasoning=ReAct(),
    tools=(Calculator(),),
)

result = agent.run("What is 17 * 23?")
print(result.answer)        # "391"
print(result.usage.total_tokens)

Features

Reasoning Strategies

• ReAct — think-act-observe loop (default, simplest)
• LATS — Language Agent Tree Search (MCTS, +90% vs ReAct on HotpotQA)
• LLM+P — LLM + symbolic planner (optimal plans for PDDL domains)

Reliability (Flagship)

• Pass^k — run k times, measure consistency. Freeze+perturb methodology.
• Event-sourced Sessions — every model/tool/retrieval call recorded. AUDIT replay, RESUME from checkpoint, RERUN fresh.
• Budget enforcement — hard limits on tokens, cost, steps, tool calls.
• Retry + timeout — transient failure recovery built-in.

Tools & MCP

• MCP-first — single Tool interface that IS MCP-shaped. Native tools and MCP servers use the same contract.
• Real stdio transport — connect_stdio() spawns real MCP server subprocesses.
• AgentAsTool — wrap any Agent as a Tool for multi-agent delegation.

Retrieval

• CRAG (Corrective RAG) — retrieval quality evaluation + web search fallback
• Adaptive-RAG — query complexity classification → route {no-retrieval/single/multi-step}

Security

• SARC model — Subject/Action/Resource/Context access control
• 6 DecisionEffects — ALLOW, DENY, MASK, PARTIAL_ALLOW, REQUIRE_APPROVAL, DEGRADE
• Two-gate model — visibility gate (CapabilityProjection) + invocation gate (authorize→execute→sanitize)
• CredentialBroker — agents never hold real credentials

Model Adapters

• OpenAI (GPT-4o, GPT-4o-mini, ...)
• Anthropic (Claude Sonnet, Opus, ...)
• FakeModel (deterministic testing)

Architecture

Agent (recipe) → Session (event-sourced process) → Environment (chokepoint)
                                                         ↕
                                              ReasoningStrategy
                                              (ReAct/LATS/LLM+P)

• Agent = immutable recipe (model + reasoning + tools + retriever)
• Session = event-sourced execution (checkpointable, replayable, auditable)
• Environment = single capability chokepoint (all calls audited, budget-metered, permission-gated)

See docs/architecture.md for full design.

Benchmark

⏳ Pending validation — see docs/validation-roadmap.md

Pass^k comparison (petfishFramework vs raw API) will be documented here after real-model benchmark runs.

Documentation

• Architecture — 5 core decisions, module structure
• API Reference — 989-line definitive reference (187 tests validate every API)
• Validation Roadmap — from paper-validated to real-validated
• Examples — 3 runnable scripts (quickstart, tools+retrieval, multi-agent)

Development

git clone https://github.com/kylecui/petfishFramework.git
cd petfishFramework
uv sync --all-extras
uv run pytest              # 166 tests
uv run ruff check src/ tests/  # lint clean

License

MIT — © 2026 Kyle Cui