Skip to main content

​
What is Context?

Context is a list of messages that tracks conversation history. Each message has a role (user, assistant, tool, system) and content. 
from a1 import get_context

ctx = get_context("main")

# Add messages
ctx.user("What is 2+2?")
ctx.assistant("4")

# Access messages
for msg in ctx:
    print(f"{msg.role}: {msg.content}")

​
Messages

Four message types: 
# User input
ctx.user("Hello")

# Assistant response
ctx.assistant("Hi there")

# Tool calls and results
ctx.assistant("", tool_calls=[...])
ctx.tool(content="result", name="tool_name", tool_call_id="id")

# System prompts (rare)
ctx.system("You are helpful")

​
Context Types

A1 uses three context types:
  • main: Clean successful execution history (user inputs + outputs)
  • attempt_*: Code generation/execution attempts (e.g., attempt_a, attempt_b)
  • intermediate_*: LLM calls from within generated code (e.g., intermediate_a)
from a1 import get_runtime

runtime = get_runtime()

# Access all contexts
for name, ctx in runtime.CTX.items():
    print(f"{name}: {len(ctx)} messages")

​
When Messages Are Added

During JIT execution:
  • User input added to main at start
  • Assistant output added to main at end
  • Tool calls added to main during execution
During AOT compilation:
  • Nothing added to main context
  • Compilation attempts tracked in attempt_* contexts
  • Each candidate gets its own attempt context
During compiled tool execution:
  • Same as regular tool execution
  • Nothing added to main context (it’s just a tool)

​
Runtime

Runtime manages all contexts for a session: 
from a1 import Runtime

runtime = Runtime()

with runtime:
    ctx = get_context("main")
    ctx.user("Hello")
Runtime handles:
  • Context lifecycle (creation, cleanup)
  • Named contexts (main, attempt_a, intermediate_a, etc.)
  • Context isolation between sessions

​
Persistence

Save and load contexts and runtime state: 
from a1 import Context, Runtime

# Auto-save context on every change
ctx = Context.from_file("chat.json", keep_updated=True)
ctx.user("Hello")  # Automatically saved

# Load context
ctx = Context.from_file("chat.json")

# Auto-save entire runtime and all contexts
runtime = Runtime.from_file("session.json", keep_updated=True)

with runtime:
    ctx = get_context("main")
    ctx.user("Hello")  # All contexts auto-saved to session.json

# Load runtime with all contexts restored
runtime = Runtime.from_file("session.json")