dsviper
The strongly typed Python runtime over the Viper C++ engine. Full Viper surface — types, values, persistence, serialization, services — exposed as Python classes ; Python natives accepted directly thanks to Metadata Everywhere.
Strong Typing
Unlike Python's permissiveness, dsviper raises exceptions immediately on type mismatch. No silent failures.
# Type checking at construction
Value.create(Type.BOOL, 4)
# ViperError: expected type 'bool', got 'int'
# Range validation
Value.create(Type.INT8, 256)
# ViperError: value is not in the range of 'int8'Native Integration
Python natives (lists, dicts, tuples) are accepted as input. Metadata drives the conversion automatically.
# Python list → Viper Vector
Value.create(TypeVector(Type.INT64), [1, 2, 3])
# Let Viper infer the type
Value.deduce([1, 2, 3]) # → Vector<int64>What's Included
The dsviper Python API surface — see the documentation for the full reference.
Types & Values
Complete type system: primitives, containers, structures, enums, variants.
Definitions
The runtime catalogue — Types + Attachments. Embedded in every database and every RPC payload ; merged on the fly. This is Metadata Everywhere.
Database
SQLite-backed persistence with transactions and schema migration.
Commit
Mutation DAG — CommitDatabase, CommitStore, the Commit Application Model — covered in its own dedicated section.
Service
Typed function pools promoted across the wire — covered in its own dedicated section.
Serialization
Binary and JSON codecs. Streaming support for large data.
Blobs
Binary large objects up to 2GB with content-addressed storage.
DSM tooling
Parse .dsm into DSM Definitions (symbolic)
and Definitions (runtime). Encode and decode between DSM,
JSON, binary, and HTML.
Quick Start
# Install from PyPI
pip install dsviper
# Verify installation
python3 -c "import dsviper; print(dsviper.version())"
# Output: (1, 2, 10)from dsviper import *
# Universal constructor — Value.create(type, [initial_value])
Value.create(TypeFloat())
# 0.0
Value.create(Type.STRING, "hello")
# 'hello'
Value.create(TypeVector(Type.INT64), [1, 2, 3])
# [1, 2, 3]
# Type checking enforced — immediate error on mismatch
Value.create(Type.BOOL, 4)
# dsviper.ViperError: expected type 'bool', got 'int'
# Range validation
Value.create(Type.INT8, 256)
# dsviper.ViperError: value is not in the range of 'int8'from dsviper import CommitDatabase, CommitMutableState, CommitStateBuilder
import model.attachments as ma
# Open a commit database
db = CommitDatabase.open("model.cdb")
# Create and modify typed data
key = ma.Tuto_UserKey.create()
login = ma.Tuto_Login()
login.nickname = "alice"
login.password = "secret"
# Commit with full history
state = CommitMutableState(CommitStateBuilder.initial_state(db))
state.attachment_mutating().set(ma.TUTO_A_USER_LOGIN, key, login)
db.commit_mutations("Add Alice", state)
# Read back
state.attachment_getting().get(ma.TUTO_A_USER_LOGIN, key)
# Optional({nickname='alice', password='secret'})Start Building
Install dsviper and follow the tutorial to build your first application.