Examples

from langgraph.graph import StateGraph, END
from substr8_langgraph import instrument_graph
from typing import TypedDict
 
class State(TypedDict):
    message: str
 
def echo(state):
    return {"message": f"Echo: {state['message']}"}
 
# Build graph
graph = StateGraph(State)
graph.add_node("echo", echo)
graph.set_entry_point("echo")
graph.add_edge("echo", END)
 
# Instrument
instrumented = instrument_graph(
    graph.compile(),
    agent_id="echo-agent",
    project="examples"
)
 
# Run
result = instrumented.invoke({"message": "Hello"})
print(result["proof_status"])  # "verified"

import json
 
result = instrumented.invoke({"query": "..."})
 
# Extract and save proof
proof = result["proof"]
with open("runproof.json", "w") as f:
    json.dump(proof.model_dump(mode="json"), f, indent=2)

# Install CLI
pip install substr8
 
# Verify proof
substr8 proof verify runproof.json
 
# Inspect details
substr8 proof inspect runproof.json

from substr8_core import verify_runproof
import json
 
with open("runproof.json") as f:
    proof = json.load(f)
 
result = verify_runproof(proof)
 
if result.valid:
    print("✓ Proof is valid")
else:
    print(f"✗ Errors: {result.errors}")

from langgraph.graph import StateGraph, END
from substr8_langgraph import instrument_graph
from typing import TypedDict, Annotated
import operator
 
class ResearchState(TypedDict):
    topic: str
    sources: Annotated[list[str], operator.add]
    summary: str
 
def search(state):
    return {"sources": [f"https://arxiv.org/search/?q={state['topic']}"]}
 
def analyze(state):
    return {"sources": [f"Analyzed {len(state['sources'])} sources"]}
 
def summarize(state):
    return {"summary": f"Summary of {state['topic']}"}
 
# Build graph
graph = StateGraph(ResearchState)
graph.add_node("search", search)
graph.add_node("analyze", analyze)
graph.add_node("summarize", summarize)
 
graph.set_entry_point("search")
graph.add_edge("search", "analyze")
graph.add_edge("analyze", "summarize")
graph.add_edge("summarize", END)
 
# Instrument and run
instrumented = instrument_graph(
    graph.compile(),
    agent_id="research-agent",
    project="examples"
)
 
result = instrumented.invoke({
    "topic": "AI governance",
    "sources": [],
    "summary": ""
})
 
print(f"Events captured: {len(result['proof'].trace)}")

from substr8_core import verify_runproof
 
result = verify_runproof(proof_dict)
 
# Check individual steps
print(f"Schema valid: {result.checks.get('schema')}")
print(f"Hash chain valid: {result.checks.get('hash_chain')}")
print(f"Merkle root valid: {result.checks.get('merkle_root')}")
print(f"Signature valid: {result.checks.get('signature')}")

git clone https://github.com/Substr8-Labs/substr8-langgraph-demo
cd substr8-langgraph-demo
pip install -r requirements.txt
python demo_agent.py
substr8 proof verify runproof.json