Sirius

Autonomous coding agent. Sirius clones your repository, implements the task, opens a pull request, and reports back - all within an isolated cloud container that has access only to your team's repo and credentials.

What Sirius Does

When you assign a task to Sirius, it spins up a dedicated cloud container, clones your GitHub repository, and uses a frontier AI model with full access to the codebase to implement the requested changes. Sirius creates a branch, commits its work, opens a pull request, and marks the task as ready for human review.

Sirius connects to your Momental workspace, so it has access to your knowledge graph, engineering standards, task context, and Code Intelligence - the same tools available to human team members.

Use Cases

Feature implementation - Build new features from task descriptions and acceptance criteria
Bug fixes - Diagnose and fix bugs with full codebase context and call-graph analysis
Test writing - Generate unit and integration tests for existing code
Refactoring - Restructure code with blast-radius awareness via Code Intelligence
Documentation - Write technical docs, blog posts, and API documentation
Migration scripts - Create and validate database migrations
Dependency updates - Upgrade packages and update affected call sites

Capabilities

Full read/write access to the cloned repository (TypeScript, JavaScript, Python, Go, and any language)
Creates branches, commits, and opens pull requests via GitHub API
Installs dependencies and runs build/test commands
Queries Code Intelligence for call graphs, blast radius, and co-change patterns before modifying code
Accesses your team's knowledge graph (PRINCIPLE, DECISION, and LEARNING atoms) for context
Reports progress via task checkpoints and comments in real time
Self-reports blockers and asks clarifying questions when needed

How It Works

Task assignment - Assign a task to Sirius via the Plans page, API, or automatic dispatch from an epic.
Container launch - A dedicated, isolated cloud container starts with your team's credentials.
Repository clone - Sirius clones your connected GitHub repository into the container.
Code Intelligence - Sirius indexes or refreshes your codebase, giving it semantic understanding of every function, caller, and dependency.
Implementation - With full codebase access, Sirius reads relevant files, plans the changes, writes code, and runs tests.
Pull request - Sirius creates a branch, commits the changes, and opens a PR. Heimdall automatically reviews the PR if connected.
Completion - Sirius marks the task as ready for review with a summary of what was done and test results.

Security Model

Your code is protected by multiple layers of isolation. Sirius never has access to another customer's repository, credentials, or data.

Ephemeral containers - Each execution runs in a dedicated, isolated container that is destroyed after the task completes. No persistent filesystem between tasks.
Single-tenant credentials - The container receives only your team's GitHub token, API key, and repo URL. No other customer's credentials exist in the environment.
Per-team GitHub tokens - GitHub App installation tokens are generated on-demand with 1-hour expiry and are never stored in our database.
Immutable API key binding - Your Momental API key is permanently bound to your team at creation. All API calls are authenticated and team-scoped.
Database isolation - Row-level security policies and application-level team filtering ensure one team cannot access another team's data.
Network isolation - All external URLs are validated against private IP ranges, cloud metadata endpoints, and loopback addresses to prevent unauthorized access.

Your source code is never stored in our database. Sirius clones your repo into an ephemeral container and the container is destroyed when the task completes. Code Intelligence builds a semantic map of your codebase (not full source files) - all scoped exclusively to your team.

AI Data Policy

Your code is never used to train, fine-tune, or improve AI models. Our AI providers operate under enterprise data processing agreements that prohibit training on customer data and enforce automatic deletion of API inputs and outputs within 30 days of processing. See our Security page for complete details.

Setup

Subscribe to Sirius - Visit Settings > Billing and upgrade to a Pro or Enterprise plan.
Connect GitHub - Go to Settings > Integrations > GitHub and install the Sirius GitHub App on your organization. Select the repositories Sirius should have access to.
(Recommended) Index your code - Run npm i -g @momentalos/cli && momental-indexer --dir . to give Sirius semantic understanding of your codebase.
Assign a task - Create a task and assign it to Sirius. Sirius handles the rest.

Access Model

Sirius is available on Pro and Enterprise plans. Each execution uses AI compute from your monthly allocation. Enterprise plans support bringing your own AI provider API key in Settings > Integrations > GitHub for direct billing.