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tags
symphony
architecture
decision
type decision
status active
area business
aliases
Architecture Decision
Open Core Model
created 2026-03-06

Architecture Decision: Open Core Model

[!info] Related See [[docs/roadmap/Production Roadmap|Production Roadmap]] for the path to managed service and [[PLANS|Phase 9]] for the Symphony Cloud implementation plan.

Context

Symphony implements the [[SPEC|Symphony orchestration spec]] (Apache 2.0, OpenAI) as a Rust-based engine. We want to:

  1. Build a healthy open-source community around the engine
  2. Offer a managed service (SaaS) for teams who don't want to self-host
  3. Protect the intellectual property that makes the managed service valuable

Decision: Two-Repo Open Core

Public: symphony (Apache 2.0)

The orchestration engine — everything needed to self-host.

symphony/
├── crates/
│   ├── symphony-core/         # Domain model (Issue, Session, Workspace)
│   ├── symphony-config/       # WORKFLOW.md parsing, live reload
│   ├── symphony-tracker/      # Linear client (+ community: GitHub, Jira)
│   ├── symphony-workspace/    # Per-issue workspace lifecycle, hooks
│   ├── symphony-agent/        # Agent subprocess runner (Claude, Codex, etc.)
│   ├── symphony-orchestrator/ # Poll loop, dispatch, retry, reconciliation
│   └── symphony-observability/# Logging, basic HTTP dashboard + API
├── src/main.rs                # CLI binary
├── examples/                  # Example WORKFLOW.md files
├── Dockerfile
└── LICENSE                    # Apache 2.0

What stays open: engine, CLI, basic dashboard, all tracker/agent plugins, WORKFLOW.md format, Docker support.

Why Apache 2.0: Matches the upstream spec license. Maximizes adoption. The engine is not the moat — the managed platform is.

Private: symphony-cloud (Proprietary)

The managed service platform — everything beyond self-hosting.

symphony-cloud/                # next-forge monorepo
├── apps/
│   ├── web/                   # Marketing site
│   ├── app/                   # Dashboard (auth, billing, tenant mgmt)
│   ├── api/                   # Control plane API
│   └── desktop/               # Tauri desktop app (later)
├── packages/
│   ├── ui/                    # Shared design system
│   ├── db/                    # Tenant configs, run history, audit logs
│   ├── symphony-client/       # TypeScript SDK for Symphony HTTP API
│   ├── auth/                  # Multi-tenant authentication (Clerk)
│   ├── billing/               # Subscriptions and usage metering (Stripe)
│   └── analytics/             # Usage tracking
└── infra/                     # Deployment, provisioning

What stays private: multi-tenancy, auth, billing, enhanced dashboard, control plane, infrastructure, desktop app.

Why private: These features represent significant engineering effort beyond the spec. They are the differentiation for the managed service.

The Line

Component Open Private Rationale
Orchestrator engine X Spec implementation, community value
CLI binary X Adoption driver
Basic HTML dashboard X Self-hosters need it
WORKFLOW.md format X Open standard
Tracker plugins X Community contributions
Agent runners X Community contributions
Docker/deployment X Self-hosting support
Multi-tenant control plane X Core SaaS infrastructure
Enhanced dashboard X Differentiated UX
Auth + team management X Enterprise feature
Billing + usage metering X Monetization
Run history + analytics X Data platform
Desktop app X Connects to cloud

Precedents

This model is used by:

  • Supabase: PostgreSQL (open) + dashboard/auth/realtime (open core)
  • GitLab: CE (open) + EE features (proprietary)
  • Grafana: AGPL core + enterprise plugins (proprietary)
  • PostHog: Open core analytics + cloud features
  • Cal.com: AGPL core + enterprise features

Monetization

Tier Price Limits
Self-hosted Free Unlimited (bring your own infra)
Starter $49/mo 3 concurrent agents, 1 project
Team $199/mo 10 agents, unlimited projects, team auth
Enterprise Custom Unlimited, SSO, SLA, dedicated infra

Future Considerations

  • If community demand is strong, consider open-sourcing the desktop app
  • Keep the TypeScript SDK (symphony-client) as a candidate for open-sourcing — it drives adoption
  • The enhanced dashboard could become open-source once the control plane is the primary moat

See Also

  • [[PLANS]] — Phase 8 (OSS release) and Phase 9 (Symphony Cloud) detail the execution plan
  • [[docs/roadmap/Production Roadmap|Production Roadmap]] — technical hardening required before launch
  • [[CONTRIBUTING]] — contributor guide for the open engine
  • [[docs/architecture/Crate Map|Crate Map]] — what ships in the open repo