Compare AI tools

	Symphony A	GitHub Copilot B	OpenRouter S	Leonardo.ai A
Tagline	OpenAI's open-source daemon that turns your Linear board into an always-on coding agent factory — tickets go in, pull requests come out.	Microsoft/GitHub's autocomplete. Deep VS Code + JetBrains integration.	One API, every model. Pay-as-you-go, no subscriptions.	Gamer + creator image gen with model fine-tuning built in.
Category	Agents	Coding	Dev Platform	Image
Pricing	Free (open-source)	Free (limited) + $10/mo Pro + $19/mo Business	Pay per token — model-dependent	Free + $12-$60/mo
Best for	Engineering teams already using Linear + OpenAI Codex who want to stop babysitting agent sessions and instead let the issue tracker drive autonomous coding at scale.	Teams with GitHub already. Devs who don't want to change IDEs.	Developers experimenting across models. Apps that want fallback logic.	Indie game devs, illustrators, anyone training custom style models.
Strengths	Fully autonomous ticket-to-PR pipeline: every open Linear issue gets its own isolated Codex agent without manual supervision Fault-tolerant Elixir/OTP architecture automatically restarts crashed agents and manages hundreds of concurrent runs WORKFLOW.md keeps all orchestration policy version-controlled inside the repo, so agent behavior is reproducible and reviewable like code Proven internal results: OpenAI reported a 500% increase in landed PRs on some teams within three weeks Open spec encourages community re-implementations in any language, not just Elixir	Great enterprise story Works in your existing IDE Chat + autocomplete	300+ models from one endpoint Automatic fallbacks between providers No subscription — just pay what you use	Train your own models on your style/character Great for game art + concept art Generous free tier
Weaknesses	Currently only supports Linear as an issue tracker — GitHub Issues and Jira integrations are not yet official Only OpenAI Codex is officially supported as the agent runtime; other model integrations are community-contributed and incomplete Self-hosted, Elixir-dependent engineering preview with no built-in sandboxing — not suitable for untrusted or production environments out of the box	Less agentic than Cursor/Claude Code Model quality varies	Slight markup over direct API Some provider features not exposed	General output behind Midjourney Can be overwhelming
Kai's verdict	Symphony is the most architecturally serious 'issue tracker as control plane' approach yet — 15K GitHub stars in weeks confirms the idea resonates — but it's still a rough, self-hosted engineering preview that demands Elixir chops and a Linear-only workflow. (Verdict pending Phi's full review.)	B-tier. Solid for autocomplete but the category moved past it. Pick Cursor unless you can't.	S-tier for model-shopping. I use this for every prototype before committing.	A-tier for creators training custom looks. B-tier for general use.
Link	Open →	Open →	Open →	Open →