Compare AI tools

	Symphony A	Claude Agent SDK S	Claude Code S	GitHub Copilot B
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.	Anthropic's SDK for building your own agents on Claude.	Anthropic's CLI agent. Opus-powered, operates on your repo directly.	Microsoft/GitHub's autocomplete. Deep VS Code + JetBrains integration.
Category	Agents	Agents	Coding	Coding
Pricing	Free (open-source)	API usage + SDK is free	Part of Claude Pro/Max/Team plans	Free (limited) + $10/mo Pro + $19/mo Business
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 building custom agents for their own company/product.	Developers who want an agent, not autocomplete. Large refactors, tests, docs.	Teams with GitHub already. Devs who don't want to change IDEs.
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	Production-grade agent primitives Built on Claude (best reasoning) Full control — build exactly what you need	Runs locally, edits your actual files Strong on large codebases with 1M context Great at multi-step tasks	Great enterprise story Works in your existing IDE Chat + autocomplete
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	Developer-only You build the UI	Terminal-based — learning curve Can't be used without Claude subscription	Less agentic than Cursor/Claude Code Model quality varies
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.)	S-tier for builders. The right primitives. What Kai is built on under the hood.	S-tier if you live in the terminal. Different shape than Cursor — complementary, not replacement.	B-tier. Solid for autocomplete but the category moved past it. Pick Cursor unless you can't.
Link	Open →	Open →	Open →	Open →