Documentation Index
Fetch the complete documentation index at: https://docs.a1project.org/llms.txt
Use this file to discover all available pages before exploring further.
Python Functions
Create tools from any async function using the @tool decorator:
from a1 import tool
@tool
async def search(query: str) -> list[str]:
"""Search the web."""
return results
@tool
async def calculate(expression: str) -> float:
"""Evaluate math expression."""
return eval(expression)
Or pass functions directly to Agent (auto-converted to tools):
async def divide(a: float, b: float) -> float:
"""Divide two numbers."""
return a / b
agent = Agent(tools=[search, divide]) # Both @tool and raw functions work
Supports primitive and complex return types (Pydantic models, lists, dicts).
Descriptions
Add descriptions to help LLMs understand tools:
@tool(
name="api_call",
description="Make an HTTP request to an endpoint"
)
async def api_call(url: str, method: str = "GET") -> str:
...
Note: The name parameter sets the tool name (defaults to the function name), and the description parameter sets the tool description (defaults to the function’s docstring).
OpenAPI
Create tools from OpenAPI 3.0 specifications:
from a1 import ToolSet
tools = await ToolSet.from_openapi("https://api.example.com")
Auto-detects spec at /openapi.json, /openapi.yaml, /swagger.json, or /swagger.yaml.
Model Context Protocol (MCP)
Create tools from MCP servers:
from a1 import ToolSet
config = {
"mcpServers": {
"filesystem": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem", "/path"]
}
}
}
tools = await ToolSet.from_mcp_servers(config)
LLM
LLMs are tools that call language models with structured output and retry logic:
from a1 import LLM, RetryStrategy
from pydantic import BaseModel
class Answer(BaseModel):
result: float
explanation: str
# Basic LLM tool
llm = LLM("gpt-4.1")
# With structured output
llm = LLM(
model="gpt-4.1",
output_schema=Answer
)
# Custom retry strategy (default: 3 candidates × 3 retries)
llm = LLM(
model="gpt-4.1",
retry_strategy=RetryStrategy(max_iterations=5, num_candidates=2)
)
Supported providers: OpenAI, Anthropic, Google, Groq (via groq:model-name)
Use LLM tools like any other tool in agents.
EMs are tools that call embedding models for semantic similarity. The use-case for this is classification. If any enum in your agent/tool schemas (input/output) has >100 values, the compiler translates all relevant LLM calls into a fused EM-LLM pipeline that first filters to semantically relevant enum options and then invokes the LLM with its output constrained to be one of the filtered options.
A1 statically detects enums that are too large and will require an EM tool if detected. A1 transparently owns adaptive rate limit handling, chunk-parallelism, and caching vectors within the current Runtime.
Semantic classification example:
from enum import Enum
from pydantic import BaseModel, Field
# Large enum (1M values)
Category = Enum('Category', {f'CAT_{i}': f'cat_{i}' for i in range(1_000_000)})
class Output(BaseModel):
category: Category
agent = Agent(
output_schema=Output,
tools=[EM("text-embedding-3-small"), LLM("gpt-4.1")] # EM required
)
RAG
RAG provides readonly or full access to databases and filesystems:
from a1 import RAG, Database, FileSystem
# Readonly database access (SELECT only)
rag = RAG(database="sqlite:///data.db")
# Readonly filesystem access (ls, grep, cat)
rag = RAG(filesystem="/path/to/files")
agent = Agent(
name="safe_agent",
tools=[rag.get_toolset(), LLM("gpt-4.1")]
)
Readonly tools: sql (SELECT), ls (list), grep (search), cat (read)
For full read/write access, use Database or FileSystem directly:
# Full database access (SELECT, INSERT, UPDATE, DELETE)
db = Database("postgresql://user:pass@host/db")
# Full filesystem access (ls, grep, cat, write_file, delete_file)
fs = FileSystem("s3://bucket/path")
agent = Agent(
tools=[db.get_toolset(), fs.get_toolset(), LLM("gpt-4.1")]
)
Supported databases: PostgreSQL, MySQL, SQLite, DuckDB, SQL Server, Oracle
Supported paths: Local filesystems, S3, Google Cloud Storage, Azure Blob Storage
ToolSet
Group related tools together to organize hierarchically:
from a1 import ToolSet
math_tools = ToolSet(
name="math",
description="Mathematical operations",
tools=[add, multiply, divide]
)
agent = Agent(
tools=[math_tools, LLM("gpt-4.1")]
)
Done
Built-in is_terminal=True tool for marking workflow completion:
from a1 import Done
done = Done() # Agent can call this to signal completion