Compare AI tools

	Symphony A	Aider A	Perplexity S
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.	Terminal-based AI pair programmer. Git-aware, model-flexible.	AI search done right. Cited answers, not chat theater.
Category	Agents	Coding	Research
Pricing	Free (open-source)	Free (open source) + whatever API you use	Free + $20/mo Pro
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.	Developers who want open-source tooling with full control.	Replacing Google for any question where you want a cited answer in seconds.
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	Works in any terminal Auto-commits changes with meaningful messages Works with any model (Claude, GPT, local) Minimal learning curve	Sources every claim Fast, current answers Pro Search runs multi-step research Spaces for persistent context
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	Terminal-only Less agentic than Claude Code Setup on Windows is fiddly	Not a general chatbot Answers can be shallow on complex topics
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.)	A-tier. The right answer if you want open-source + terminal-native + model-agnostic.	S-tier for search. I use it before Google now. If you're still Googling everything, try this for a week.
Link	Open →	Open →	Open →