VCP Python SDK

The Python project-maintained implementation for VCP parsing, signed bundles, orchestration, policy enforcement, privacy filtering, hooks, messaging, and protocol extensions.

Agent Runtime Profile candidate

The vcp.agent facade provides complete local reference behavior for observe, controlled, and accretive profile levels. It preserves bounded orientation, explicit assurance, contextual Affordances, proof-first runs, exact single-use authority, interruption and reconciliation, evidence-based completion, candidate-first learning, attributable reuse, and revocation.

from vcp.agent import AgentRuntime

async with AgentRuntime.connect(profile="accretive@0.1.0") as runtime:
    situation = (await runtime.bootstrap("Complete one governed task")).require_value()

Local mode opens no network and grants no production authority. Run vcp doctor --json before feature use to detect distribution collisions. See the complete guide and the eight executable examples.

Install for development

Python 3.10 or newer is required.

Publication state: source-only candidate. No PyPI release is currently claimed. Commands below operate on this checkout.

python3 -m venv .venv
. .venv/bin/activate
python -m pip install -e '.[dev]'

The package distribution is named value-context-protocol. Python imports use the vcp namespace.

Verify the package

python -m pytest -q
python -m ruff check src tests
python -m ruff format --check src tests
python -m mypy src/vcp
python -m build
python -m pip_audit

Minimal usage

from vcp.identity import Token
from vcp.semantics.csm1 import CSM1Code

token = Token.parse("family.safe.guide@1.2.0")
profile = CSM1Code.parse("N5+F+E")
print(token.full)
print(profile.encode())

Real Ed25519 bundle construction and verification are demonstrated in ../examples/python/02_verify_bundle.py. The full pipeline example verifies before preparing model-context injection.

Optional features

python -m pip install -e '.[server]'
python -m pip install -e '.[mcp]'

Install the MCP extra and run the packaged stdio server with:

python -m pip install -e '.[mcp]'
vcp-mcp-server

The historical host API adapter is archived outside the package source and is excluded from distributions. Development and CI use the committed lock file. Update it deliberately through the documented command in ../CONTRIBUTING.md.

Signed-skill manifests are written as private workspace state by default. On POSIX platforms the atomic temporary file and installed manifest.json use mode 0600. Windows does not provide equivalent POSIX mode semantics, so the application must protect the containing directory with its native access controls. A separately published manifest is a deliberate export and should receive only the permissions required by its publication target.

Related surfaces

• Rust SDK
• WebMCP SDK
• Conformance fixtures
• Compatibility policy