Main Sequence TAU SDK

Run Tau as a workspace-native Main Sequence coding agent.

ms-tau-sdk packages the Tau runtime integration, Main Sequence authentication and transports, and durable agent-session machinery as a normal Python dependency. A project installs the SDK and runs it from its own workspace—there is no separate Astro image, executor overlay, or second deployment model.

Quick start

Add the SDK to the project that will host the agent:

uv add ms-tau-sdk

Provide the runtime credential that Main Sequence assigned to the deployment:

export MAINSEQUENCE_BACKEND="https://api.main-sequence.app"
export MAINSEQUENCE_RUNTIME_CREDENTIAL_ID="<runtime-credential-id>"
export MAINSEQUENCE_RUNTIME_CREDENTIAL_SECRET="<runtime-credential-secret>"

Start the service from the project workspace:

uv run ms-tau

The credential pair is exchanged for short-lived Main Sequence access tokens. Do not commit it or place it in .tau configuration. For an embedded ASGI deployment, construct the same application in Python:

from ms_tau_sdk import create_app

app = create_app()

Workspace-owned Tau behavior

The consuming repository owns the effective Tau configuration. It can override the packaged Tau defaults and install project-specific tools through the normal .tau/ structure:

your-project/
├── .tau/
│   ├── SYSTEM.md
│   ├── settings.json
│   └── extensions/
├── pyproject.toml
└── uv.lock

Extensions run as project code in the same process and trust boundary as the rest of the repository. Optional capabilities such as general web access belong in a project extension; they are not bundled into the SDK. Main Sequence transport and protocol behavior remains SDK-owned.

Included capabilities

• FastAPI application construction and lifecycle management
• runtime-credential exchange and authenticated Main Sequence backend access
• provider validation and credential hydration
• durable Tau sessions, leases, restore, persistence, cancellation, eviction, and shutdown
• sessionless Tau execution
• chat, responses, SSE, A2A, health, and readiness transports
• Main Sequence MCP and protocol-required task controls
• packaged defaults that participate in Tau's normal workspace configuration

Deployment boundary

This repository publishes Python distributions only. It contains no Dockerfile, Compose stack, Kubernetes manifest, runtime image, executor bundle, or container-publication pipeline. The consuming project owns its dependency lock, deployable artifact, system dependencies, project code, prompts, skills, hooks, and extensions.

The project identity and migration are defined by ADR 56. See the quickstart, documentation index, and release guide for the complete contracts.

Development

The repository uses Python 3.13 and uv:

uv sync --frozen
uv run pytest
uv run ruff check .
uv run mypy

Releases are immutable and tag-driven. Pushing a tag that exactly matches the package version—for example, v1.0.0—builds and verifies the wheel and source distribution, then publishes them to PyPI through OIDC trusted publishing. No PyPI API token or container registry is involved.

Built on Tau

Main Sequence TAU SDK integrates the open-source Tau coding agent into the Main Sequence platform while preserving Tau's workspace-native configuration and extension model.