LegionvsOpenAI Agents Go SDK
Generated from the two spec rows. Green marks the better value where a spec has a clear direction. Everything else is just different.
Legion
Software Mansion · Agent framework
OSS
Panel
6.52 spec wins
- Reliability
- 6.0
- Usefulness
- 6.2
- Cost
- 8.0
- Longevity
- 5.8
“It writes Lua to get work done in Elixir, which is two functional languages agreeing that a third one should take the blame.”
OpenAI Agents Go SDK
NLP Odyssey · Agent framework
OSSMCP
Panel
6.44 spec wins
- Reliability
- 6.5
- Usefulness
- 5.8
- Cost
- 7.7
- Longevity
- 5.5
“Its agents perform handoffs to each other, making this the only workplace where a handoff has ever gone smoothly.”
Spec by spec
| Spec | Legion | OpenAI Agents Go SDK |
|---|---|---|
| Architecture | ||
| Category | Agent framework | Agent framework |
| Runs | local | local |
| Platforms | macos, linux | macos, linux, windows |
| Context window | not documented | not documented |
| Protocols | ||
| MCP client | No | Yes |
| MCP server | No | No |
| Capabilities | ||
| Runs terminal commands | No | No |
| Multi-file edits | Yes | No |
| Git operations | No | No |
| Browser control | No | YesOnly through OpenAI's hosted computer-use and web-search tools, which the SDK exposes; there is no browser driver in the project. |
| Sandboxed execution | YesLegion runs generated Lua or Elixir in its own sandbox; the README does not describe a container runtime. | No |
| Multi-agent orchestration | No | Yes |
| Headless / CI mode | No | No |
| Models | ||
| Backbone | multiple providers | OpenAI |
| Bring your own model | Yes | YesCustom model providers and proxies such as LiteLLM are covered by the model_providers examples. |
| Local models | No | No |
| Cost | ||
| Pricing model | byok | byok |
| Starts at | $0/mo | $0/mo |
| Free tier | Yes | Yes |
| Bring your own key | Yes | Yes |
| Openness | ||
| Open source | Yes | Yes |
| License | MIT | Apache-2.0 |
| GitHub stars | 220 | 273 |
Which one would each critic pick
| Critic | Legion | OpenAI Agents Go SDK | Pick |
|---|---|---|---|
| El Juez | — | — | not enough reviews |
| El Amigo | 6.8 | 6.3 | Legion — Pick Legion if you write Elixir and want the agent inside the application rather than beside it; pick a framework in Python if the rest of your stack already lives there. |
| El Crítico | 6.0 | 5.5 | Legion — The generated snippet runs in the project's own sandbox, and the README does not describe a container runtime, so the isolation boundary is whatever the host process could already reach. |
| El Profesor | 7.8 | 7.5 | Legion — One evaluation can filter, branch and loop, so a sequence that costs a tool-calling agent a model round trip per step collapses into a single call. The claim is structural and checkable. |
| La Inversora | 6.3 | 5.5 | Legion — 166 stars and a consultancy's name on it. Software Mansion builds open libraries to sell engineering time, which funds this exactly as long as the pitch still works. |
| La Jefa | 5.5 | 6.0 | OpenAI Agents Go SDK — Nothing to license for sixty engineers and nothing to install on their desks, but it is a library in one language, so the audience is whichever teams already write in it. |
| El Hacker | 6.8 | 7.5 | OpenAI Agents Go SDK — Apache-2.0, one module dependency, tool servers attach both locally and remotely, and the model layer takes a custom provider so a proxy like LiteLLM sits in front of anything. |
Picks are derived from each critic's own scores. Humans vote on matchups on the duels page.