Imported from huakaibiantian1/benchmark_opensource_pub (tau2-bench/AGENTS.md). Install upstream with npx skills add huakaibiantian1/benchmark_opensource_pub --skill tau2-bench. Copyright stays with the author.

AGENTS.md

Instructions for AI coding agents working on the τ-bench codebase.

Project Overview

τ-bench is a simulation framework for evaluating conversational customer service agents. It supports text and voice interactions in half-duplex (turn-based) and full-duplex (simultaneous/streaming) communication modes. Domains include mock, airline, retail, telecom, and banking_knowledge.

Setup

uv sync                        # core only (airline, retail, telecom, mock)
uv sync --extra voice          # + voice/audio-native features
uv sync --extra knowledge      # + banking_knowledge domain (retrieval pipeline)
uv sync --extra gym            # + gymnasium RL interface
uv sync --extra dev            # + pytest, ruff, pre-commit (required for committing)
uv sync --extra experiments    # + plotting libs for src/experiments/
uv sync --all-extras           # everything
uv run tau2 check-data         # verify installation

Note: langfuse and redis are not declared dependencies but may be needed if you enable USE_LANGFUSE=True or LLM_CACHE_ENABLED=True with redis cache type in config.py. Install them manually if needed (uv pip install langfuse redis).

Environment variables: copy .env.example to .env and set API keys. Uses LiteLLM for LLM provider abstraction.

Required keys depend on the task:

• OPENAI_API_KEY / ANTHROPIC_API_KEY — for LLM-based agents and user simulators
• ELEVENLABS_API_KEY — voice synthesis
• DEEPGRAM_API_KEY — voice transcription

Common Commands

make test is the safe default -- it works with just uv sync --extra dev and does not require voice, knowledge, or gym packages. Always run make check-all before committing. A pre-commit hook enforces this.

Running Evaluations

# Text half-duplex (standard)
tau2 run --domain airline --agent-llm gpt-4.1 --user-llm gpt-4.1 --num-trials 1 --num-tasks 5

# Voice full-duplex (audio native)
tau2 run --domain retail --audio-native --num-tasks 1 --verbose-logs

# Knowledge domain (requires --retrieval-config)
tau2 run --domain banking_knowledge --retrieval-config qwen_embeddings --agent-llm gpt-4.1 --user-llm gpt-4.1 --num-tasks 5

Results go to data/simulations/. Use tau2 view to browse them.

Architecture

src/tau2/
├── agent/           # Agent implementations (half-duplex and full-duplex)
├── api_service/     # FastAPI-based API service
├── config.py        # Central configuration (single source of truth for defaults)
├── cli.py           # CLI entry point (tau2 command)
├── data_model/      # Pydantic data models (messages, trajectories, etc.)
├── domains/         # Domain definitions (airline, mock, retail, telecom, banking_knowledge)
├── environment/     # Environment, DB, server, toolkit base classes
├── evaluator/       # Task evaluation logic
├── gym/             # Gymnasium-compatible RL interface
├── knowledge/       # Knowledge retrieval pipeline (embedders, retrievers, postprocessors, sandbox)
├── metrics/         # Metrics computation
├── orchestrator/    # Simulation orchestrators (half-duplex, full-duplex)
├── registry.py      # Global registry for agents, domains, tasks, users
├── runner/          # Simulation runner (batch execution, checkpointing, build helpers)
├── scripts/         # CLI command implementations
├── user/            # User simulator implementations
├── utils/           # Shared utilities
└── voice/           # Voice synthesis, transcription, audio-native providers
    └── audio_native/  # Real-time voice providers (openai, gemini, nova, xai, deepgram, qwen, livekit)

Other top-level directories:

• data/ — Domain data (JSON, TOML, policies), simulation outputs
• tests/ — All tests (pytest)
• scripts/ — Standalone utility scripts
• src/experiments/ — Research/experimental code (self-contained)
• docs/ — User-facing documentation

Key Patterns

Registry System

All agents, domains, tasks, and user simulators are registered in src/tau2/registry.py. To add a new component, register it there:

registry.register_agent_factory(create_my_agent, "my_agent")
registry.register_domain(get_environment, "my_domain")
registry.register_tasks(get_tasks, "my_domain", get_task_splits=get_tasks_split)

Agent Architecture

Two base classes, determined by communication mode:

Both share the constructor signature: __init__(self, tools: list[Tool], domain_policy: str). For LLM-based agents, mix in LLMConfigMixin to add llm and llm_args parameters.

Domain Structure

Each domain (src/tau2/domains/<name>/) contains:

• data_model.py — DB subclass with domain data models
• tools.py — ToolKitBase subclass with domain tools
• environment.py — get_environment(), get_tasks(), get_tasks_split()
• user_tools.py (optional) — user-facing tools
• utils.py — data paths and helpers

Domain data lives in data/tau2/domains/<name>/ (tasks.json, policy.md, db.json/toml, etc.).

Note: The banking_knowledge domain extends the standard pattern with additional files (retrieval.py, retrieval_mixins.py, retrieval_toolkits.py, db_query.py), dynamic tools and policy that vary by --retrieval-config, and a separate knowledge/ retrieval pipeline module. Its data directory also includes documents/, prompts/, and tasks/ subdirectories. See src/tau2/knowledge/README.md for details.

Orchestrators

• Orchestrator — half-duplex, turn-based, synchronous tool execution
• FullDuplexOrchestrator — full-duplex, tick-based, simultaneous agent/user activity

Testing

Tests are split into tiers matching the optional dependency groups. Each tier has its own Make target and required install extras:

# Core tests — works with just `uv sync --extra dev`
make test

# Voice + streaming tests — requires `uv sync --extra voice --extra dev`
make test-voice

# Banking knowledge tests — requires `uv sync --extra knowledge --extra dev`
make test-knowledge

# Gymnasium tests — requires `uv sync --extra gym --extra dev`
make test-gym

# All tests — requires `uv sync --all-extras`
make test-all

# Domain-specific (core domains work with `make test`)
pytest tests/test_domains/test_<domain_name>

# Specific test file
pytest tests/test_agent.py

# Skip full-duplex integration tests (require live APIs)
pytest -m "not full_duplex_integration"

Test layout mirrors source:

• tests/test_domains/ — per-domain tool and user-tool tests (except test_banking_knowledge/ which requires the knowledge extra)
• tests/test_streaming/ — streaming/full-duplex tests (requires voice extra)
• tests/test_voice/ — audio-native provider tests (requires voice extra; individual providers gated by {PROVIDER}_TEST_ENABLED=1)
• tests/test_gym/ — gymnasium RL interface tests (requires gym extra)

Code Style

• Formatter/linter: Ruff (configured in pyproject.toml)
• Line length: 88 characters
• Python: >=3.12, <3.14
• Type hints: Encouraged, especially for public APIs
• Docstrings: Required for public APIs and complex functions
• Import sorting: Handled by ruff
• Models: Use Pydantic BaseModel for data classes

Ruff rules: E4, E7, E9, F, I (with E501 and F541 ignored).

Commit Conventions

feat: add memory system to agent base class
fix: resolve environment tool timeout issues
docs: update domain contribution guidelines
test: add integration tests for retail domain

Things to Watch Out For

• .env file: Never commit this. Contains API keys. Use .env.example as reference.
• data/ directory: Contains domain data that the framework depends on. Be careful modifying JSON/TOML data files.
• config.py: Single source of truth for default configuration values. Import constants from here rather than defining local duplicates.
• registry.py: All new agents, domains, and user simulators must be registered here to be usable via CLI.
• Audio native providers: Each has its own WebSocket protocol and event format. Always verify against provider documentation. See .cursor/rules/audio-native-provider.md for the full implementation guide.
• Task splits: The base split is the default for evaluation. The train/test splits are for RL experiments.
• Pre-commit hook: Runs make check-all (ruff lint + format). Fix any issues before committing.
• Notebooks: Excluded from ruff (*.ipynb in pyproject.toml exclude).
• banking_knowledge domain: Uses --retrieval-config to specify how the agent accesses the knowledge base. If omitted, defaults to alltools (BM25 + dense + shell; see src/tau2/knowledge/README.md). For offline-only, use e.g. bm25. Other offline configs: no_knowledge, full_kb, golden_retrieval, bm25_grep, grep_only. openai_embeddings* and default alltools require OPENAI_API_KEY. qwen_embeddings* and alltools-qwen require OPENROUTER_API_KEY (included in .env.example). *_reranker configs additionally require OPENAI_API_KEY for the LLM reranker. terminal_use*, alltools, and alltools-qwen require sandbox-runtime: install via npm install -g @anthropic-ai/sandbox-runtime@0.0.23 AND the system tools it shells out to (apt install ripgrep bubblewrap socat on Linux, brew install ripgrep on macOS) — SandboxManager raises SandboxRuntimeError at construction time if any are missing. Embedding cache lives in data/.embeddings_cache (gitignored). See src/tau2/knowledge/README.md for full details.