Compare AI tools

	GitHub Copilot B	OpenRouter S	Symphony A	Aider A
Tagline	Microsoft/GitHub's autocomplete. Deep VS Code + JetBrains integration.	One API, every model. Pay-as-you-go, no subscriptions.	OpenAI's open-source daemon that turns your Linear board into an always-on coding agent factory — tickets go in, pull requests come out.	Terminal-based AI pair programmer. Git-aware, model-flexible.
Category	Coding	Dev Platform	Agents	Coding
Pricing	Free (limited) + $10/mo Pro + $19/mo Business	Pay per token — model-dependent	Free (open-source)	Free (open source) + whatever API you use
Best for	Teams with GitHub already. Devs who don't want to change IDEs.	Developers experimenting across models. Apps that want fallback logic.	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.	Developers who want open-source tooling with full control.
Strengths	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	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	Works in any terminal Auto-commits changes with meaningful messages Works with any model (Claude, GPT, local) Minimal learning curve
Weaknesses	Less agentic than Cursor/Claude Code Model quality varies	Slight markup over direct API Some provider features not exposed	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	Terminal-only Less agentic than Claude Code Setup on Windows is fiddly
Kai's verdict	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.	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.)	A-tier. The right answer if you want open-source + terminal-native + model-agnostic.
Link	Open →	Open →	Open →	Open →