astreum 0.3.57

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.
cold_storage_level_size	int	10485760	Size threshold (10 MiB) for collating level_0 into the first cold-storage index/data pair.
atom_fetch_interval	float	0.25	Poll interval (seconds) while waiting for missing atoms in get_atom_list_from_storage; 0 disables waiting.
atom_fetch_retries	int	8	Number of poll attempts for missing atoms; max wait is roughly interval * retries, 0 disables waiting.
logging_retention_days	int	7	Number of days to keep rotated log files (daily gzip).
chain_id	int	0	Chain identifier used for validation (0 = test, 1 = main).
verbose	bool	False	When True, also mirror JSON logs to stdout with a human-readable format.

Communication

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	52780	UDP port the relay binds to; pass 0 or omit to let the OS pick an ephemeral port.
default_seed	string	"bootstrap.astreum.org:52780"	Default address to ping before joining; set to None to disable the built-in default.
additional_seeds	list[str]	[]	Extra addresses appended to the bootstrap list; each must look like host:port or [ipv6]:port.
peer_timeout	int	900	Evict peers that have not been seen within this many seconds (15 minutes).
peer_timeout_interval	int	10	How often (seconds) the peer manager checks for stale peers.
bootstrap_retry_interval	int	30	How often (seconds) to retry bootstrapping when the peer list is empty.
storage_index_interval	int	600	How often (seconds) to re-advertise entries in node.atom_advertisments to the closest known peer.
incoming_queue_size_limit	int	67108864	Soft cap (bytes) for inbound queue usage tracked by enqueue_incoming; set to 0 to disable.
incoming_queue_timeout	float	1.0	When > 0, enqueue_incoming waits up to this many seconds for space before dropping the payload.
outgoing_queue_size_limit	int	67108864	Soft cap (bytes) for enqueue_outgoing-tracked outgoing queue usage; set to 0 to disable.
outgoing_queue_timeout	float	1.0	When > 0, enqueue_outgoing waits up to this many seconds for space before dropping the payload.

Advertisements: node.atom_advertisments holds (atom_id, payload_type, expires_at) tuples. Use node.add_atom_advertisement or node.add_atom_advertisements to enqueue entries (expires_at=None keeps them indefinite). Validators automatically advertise block, transaction (main and detail lists), receipt, and account trie lists for 15 minutes by default.

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": 52780,
    "use_ipv6": False,
    "default_seed": None,
    "additional_seeds": [
        "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 7 days by default. Override via config["logging_retention_days"].
• 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 .

for all tests

python3 -m unittest discover -s tests

for individual tests

python3 -m unittest tests.node.test_current_validator
python3 -m unittest tests.node.test_node_connection
python3 -m unittest tests.node.test_node_init
python3 -m unittest tests.node.test_node_validation
python3 -m unittest tests.node.config.default_seed
python3 -m unittest tests.node.tokenize
python3 -m unittest tests.node.parse
python3 -m unittest tests.node.function
python3 -m unittest tests.node.stack
python3 -m unittest tests.models.test_merkle
python3 -m unittest tests.models.test_patricia
python3 -m unittest tests.block.atom
python3 -m unittest tests.block.nonce