LLB (Large Language Blocks)

A Python library for generating LLM-readable structured context.

Why LLB?

Serialize Python objects (especially graphs) into LLM-friendly text:

• Graph Mode: Nodes + edges with focus/radius context pruning
• Flat Mode: Simple independent block packaging

Installation

pip install llb_doc

Quick Start

Flat Mode - Independent Blocks

from llb_doc import create_llb, parse_llb

doc = create_llb()

# Method 1: Fluent API with builder pattern
doc.block("ticket", lang="en").meta(source="jira", priority="high").content(
    "User cannot upload files larger than 10MB"
).add()

# Method 2: Context manager
with doc.block("api", "json") as b:
    b.meta["source"] = "storage_service"
    b.content = '{"max_size": 5242880, "unit": "bytes"}'

# Method 3: Direct add
doc.add_block("note", "Config mismatch detected", source="code_review", lang="en")

# Render to LLB format
print(doc.render())

# Parse LLB text back to document
doc2 = parse_llb(doc.render())

Output

@block B1 ticket en
source=jira
priority=high

User cannot upload files larger than 10MB

@end B1

@block B2 api json
source=storage_service

{"max_size": 5242880, "unit": "bytes"}

@end B2

@block B3 note en
source=code_review

Config mismatch detected

@end B3

Graph Mode - Connected Nodes

from llb_doc import create_graph

g = create_graph()

# Add nodes
python = g.add_node("concept", "Python", id_="python", category="language")
django = g.add_node("concept", "Django", id_="django", category="framework")
flask = g.add_node("concept", "Flask", id_="flask", category="framework")

# Add edges
g.add_edge("python", "django", "has_framework")
g.add_edge("python", "flask", "has_framework")

# Render with focus and radius
print(g.render(focus="python", radius=1))

Output

@ctx C1
focus=python
radius=1
strategy=bfs
tiers=0:python;1:django,flask
@end C1

@node django concept
category=framework
tier=1
in_edges=['python:has_framework']
out_edges=[]

Django

@end django

@node flask concept
category=framework
tier=1
in_edges=['python:has_framework']
out_edges=[]

Flask

@end flask

@edge E1 python django has_framework @end

@edge E2 python flask has_framework @end

@node python concept
category=language
tier=0
in_edges=[]
out_edges=['django:has_framework', 'flask:has_framework']

Python

@end python

Block Structure

Each block follows this structure:

@block <id> <type> [lang]
key1=value1
key2=value2

<content>

@end <id>

Features

Document Operations

doc = create_llb()
b1 = doc.add_block("task", "First task")
b2 = doc.add_block("task", "Second task")

# Check, get, remove blocks
doc.has_block(b1.id)        # True
doc.get_block(b1.id)        # Block object
doc.remove_block(b1.id)     # Remove and return block

# Reorder blocks
doc.move_block(b2.id, 0)    # Move to position
doc.swap_blocks(b1.id, b2.id)  # Swap positions

# Prefix and suffix
doc.prefix = "# Analysis Context"
doc.suffix = "# End"

Custom Meta Generators

Auto-generate metadata for blocks:

from llb_doc import create_llb, meta_generator, Block

@meta_generator("word_count")
def gen_word_count(block: Block) -> str:
    return str(len(block.content.split()))

doc = create_llb(generators=[gen_word_count])
doc.add_block("text", "Hello world!")
print(doc.render())
# word_count=2 will be auto-added

Custom Block Sorters

Sort blocks in custom order:

from llb_doc import create_llb, block_sorter, Block

@block_sorter("by_priority")
def sort_by_priority(blocks: list[Block]) -> list[Block]:
    order = {"high": 0, "medium": 1, "low": 2}
    return sorted(blocks, key=lambda b: order.get(b.meta.get("priority", ""), 99))

doc = create_llb(sorters=[sort_by_priority])
doc.add_block("task", "Task A", priority="low")
doc.add_block("task", "Task B", priority="high")
print(doc.render(order="by_priority"))

Graph Mode Features

g = create_graph()

# Builder pattern for nodes
g.node("person").id("p1").meta(name="Alice").content("Developer").add()

# Builder pattern for edges
g.edge("p1", "c1", "works_at").meta(since="2020").content("Full-time").add()

# Render with different sorting strategies
g.render(focus="p1", radius=2, order="focus_last")   # Default: focus at end
g.render(focus="p1", radius=2, order="focus_first")  # Focus at beginning
g.render(focus="p1", radius=2, order="tier_asc")     # By tier ascending
g.render(focus="p1", radius=2, order="tier_desc")    # By tier descending

# Render all nodes without focus
g.render()  # No @ctx block, shows all nodes and edges

Free Mode - Full Control

For complex scenarios where you need explicit control over which nodes and edges to render:

from llb_doc import create_graph, Ctx

g = create_graph()
g.add_node("person", "Alice's full bio...", id_="N1")
g.add_node("person", "Bob's full bio...", id_="N2")
g.add_node("person", "Carol's full bio...", id_="N3")
g.add_edge("N1", "N2", "knows", id_="E1")
g.add_edge("N2", "N3", "knows", id_="E2")

# Render specific nodes/edges in exact order
# Use tuple (id, True) for brief mode (meta only, no content)
output = g.render_free(
    items=[
        "N1",           # full render
        ("N2", True),   # brief render (no content)
        "E1",           # full render
    ],
    ctx={
        "content": "Custom neighborhood view",
        "meta": {"view": "neighborhood", "roots": "N1"},
    },
)

# Custom brief renderer
output = g.render_free(
    items=["N1", ("N2", True), ("N3", True)],
    brief_renderer=lambda b: f"@{b.type} {b.id} [brief] @end",
)

Free mode features:

• Explicit ordering: Items render in the exact order you specify
• Brief mode: Use (id, True) tuple to render only meta (no content)
• Custom brief renderer: Pass a function to fully customize brief output
• Optional ctx: Pass dict or Ctx object, automatically placed at top

API Reference

Main Functions

Function	Description
create_llb()	Create a new Document for flat mode
create_graph()	Create a new GraphDocument for graph mode
parse_llb(text)	Parse LLB format text into Document

GraphDocument Methods

Method	Description
render(focus, radius, ...)	Render with BFS-based focus/radius filtering
render_free(items, ctx, brief_renderer)	Render with explicit control over nodes/edges
add_node(type, content, ...)	Add a node to the graph
add_edge(from_id, to_id, rel, ...)	Add an edge between nodes

Decorators

Decorator	Description
@meta_generator(key)	Register a metadata generator function
@block_sorter(name)	Register a block sorter function

Classes

Class	Description
Document	Container for blocks in flat mode
GraphDocument	Container for nodes, edges in graph mode
Block	Basic block with type, lang, meta, content
Node	Graph node (renders as @node)
Edge	Graph edge (renders as @edge)
Ctx	Graph context (renders as @ctx)

Types

Type	Description
ItemSpec	str | tuple[str, bool] - Item ID or (ID, brief) tuple
BriefRenderer	Callable[[Block], str] - Custom brief render function

Demo

Run the demo script to see all features in action:

python demo.py

License

MIT