astreum 0.3.18

Python library to interact with the Astreum blockchain and its virtual machine.

lib

Python library to interact with the Astreum blockchain and its virtual machine.

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Configuration

When initializing an astreum.Node, pass a dictionary with any of the options below. Only the parameters you want to override need to be present – everything else falls back to its default.

Core Configuration

Parameter	Type	Default	Description
hot_storage_limit	int	1073741824	Maximum bytes kept in the hot cache before new atoms are skipped (1 GiB).
cold_storage_limit	int	10737418240	Cold storage write threshold (10 GiB by default); set to 0 to skip the limit.
cold_storage_path	string	None	Directory where persisted atoms live; Astreum creates it on startup and skips cold storage when unset.
logging_retention	int	90	Number of days to keep rotated log files (daily gzip).
verbose	bool	False	When True, also mirror JSON logs to stdout with a human-readable format.

Networking

Parameter	Type	Default	Description
relay_secret_key	hex string	Auto-generated	X25519 private key used for the relay route; a new keypair is created when this field is omitted.
validation_secret_key	hex string	None	Optional Ed25519 key that lets the node join the validation route; leave blank to opt out of validation.
use_ipv6	bool	False	Bind the incoming/outgoing sockets on IPv6 (the OS still listens on IPv4 if a peer speaks both).
incoming_port	int	7373	UDP port the relay binds to; pass 0 or omit to let the OS pick an ephemeral port.
bootstrap	list[str]	[]	Addresses to ping with a handshake before joining; each must look like host:port or [ipv6]:port.

Note The peer‑to‑peer route used for object discovery is always enabled. If validation_secret_key is provided the node automatically joins the validation route too.

Example

from astreum.node import Node

config = {
    "relay_secret_key": "ab…cd",             # optional – hex encoded
    "validation_secret_key": "12…34",        # optional – validator
    "hot_storage_limit": 1073741824,         # cap hot cache at 1 GiB
    "cold_storage_limit": 10737418240,       # cap cold storage at 10 GiB
    "cold_storage_path": "./data/node1",
    "incoming_port": 7373,
    "use_ipv6": False,
    "bootstrap": [
        "bootstrap.astreum.org:7373",
        "127.0.0.1:7374"
    ]
}

node = Node(config)
# … your code …

Astreum Machine Quickstart

The Astreum virtual machine (VM) is embedded inside astreum.Node. You feed it Astreum script, and the node tokenizes, parses, and evaluates.

# Define a named function int.add (stack body) and call it with bytes 1 and 2

import uuid
from astreum import Node, Env, Expr

# 1) Spin‑up a stand‑alone VM
node = Node()

# 2) Create an environment (simple manual setup)
env_id = uuid.uuid4()
node.environments[env_id] = Env()

# 3) Build a function value using a low‑level stack body via `sk`.
# Body does: $0 $1 add   (i.e., a + b)
low_body = Expr.ListExpr([
    Expr.Symbol("$0"),  # a (first arg)
    Expr.Symbol("$1"),  # b (second arg)
    Expr.Symbol("add"),
])

fn_body = Expr.ListExpr([
    Expr.Symbol("a"),
    Expr.Symbol("b"),
    Expr.ListExpr([low_body, Expr.Symbol("sk")]),
])

params = Expr.ListExpr([Expr.Symbol("a"), Expr.Symbol("b")])
int_add_fn = Expr.ListExpr([fn_body, params, Expr.Symbol("fn")])

# 4) Store under the name "int.add"
node.env_set(env_id, "int.add", int_add_fn)

# 5) Retrieve the function and call it with bytes 1 and 2
bound = node.env_get(env_id, "int.add")
call = Expr.ListExpr([Expr.Bytes(b"\x01"), Expr.Bytes(b"\x02"), bound])
res  = node.high_eval(env_id, call)

# sk returns a list of bytes; for 1+2 expect a single byte with value 3
print([int.from_bytes(b.value, 'big', signed=True) for b in res.elements])  # [3]

Handling errors

Both helpers raise ParseError (from astreum.machine.error) when something goes wrong:

• Unterminated string literals are caught by tokenize.
• Unexpected or missing parentheses are caught by parse.

Catch the exception to provide developer‑friendly diagnostics:

try:
    tokens = tokenize(bad_source)
    expr, _ = parse(tokens)
except ParseError as e:
    print("Parse failed:", e)

---

Logging

Every Node instance wires up structured logging automatically:

• Logs land in per-instance files named node.log under %LOCALAPPDATA%\Astreum\lib-py\logs/<instance_id> on Windows and $XDG_STATE_HOME (or ~/.local/state)/Astreum/lib-py/logs/<instance_id> on other platforms. The <instance_id> is the first 16 hex characters of a BLAKE3 hash of the caller's file path, so running the node from different entry points keeps their logs isolated.
• Files rotate at midnight UTC with gzip compression (node-YYYY-MM-DD.log.gz) and retain 90 days by default. Override via config["logging_retention"].
• Each event is a single JSON line containing timestamp, level, logger, message, process/thread info, module/function, and the derived instance_id.
• Set config["verbose"] = True to mirror logs to stdout in a human-friendly format like [2025-04-13-42-59] [info] Starting Astreum Node.
• The very first entry emitted is the banner Starting Astreum Node, signalling that the logging pipeline is live before other subsystems spin up.

Testing

python3 -m venv venv
source venv/bin/activate
pip install -e .
python3 -m unittest discover -s tests