lema · docs
Check the record before you build it
A model with your repo indexed knows what the code does. It can’t recover why an alternative was argued and ruled out — that reasoning is never written into the code. Fusion answers it.
What it is
Name an approach against a covered project and learn whether it was already ruled out, with the recorded why-not, cited, plus a pointer to the project’s own docs. It’s the same typed context a coding agent receives from the check_approach tool. A why-not is summarized from the record, not quoted.
How it works
- 1You — or your agent, via
check_approach— name an approach against a covered project (React, Kubernetes, Rust, Vue, and Go over MCP; /fuse also serves Ethereum EIPs). - 2lema checks the project’s recorded deliberation.
- 3If the approach was ruled out, you get the cited why-not and a HOWpointer to the project’s hosted docs for the current guidance.
- 4If nothing was ruled out but the record holds the reasoning, the answer carries a cited
why— the recorded rationale, kept distinct from a ruling. - 5If there is no recorded ruling, you get an explicit
no_recorded_ruling— unknown, not approval.
The typed context
check_approach returns a small, typed envelope — the same shape your agent receives: the verdict, the summarized why_not, the rejection sources each with their ref, and a howpointer to the project’s docs.
This is an example shape — run a live check on /fuse for a real, cited result. Each source carries a binding cosine — relevance, not confidence — measured per call, and omitted here rather than shown as a fixed number.
{ "repo": "facebook/react", "approach": "<the approach you named>", "verdict": "ruled_out", "why_not": "<summarized from the record — never a verbatim quote>", "sources": [ { "n": 1, "ref": "<owner/repo#123>", "type": "rfc" } ], "how": { "doc_home": "react.dev", "topic": "<where to read more>" }}
Why it’s different
Documentation tools carry the what — the current API and syntax. Reconstructing a whyfrom a model is fluent and sometimes wrong. Fusion returns the project’s actual recorded rejection, with a citation — the ruled-out alternative the code structurally can’t show. lema owns the binding (the cited why-not); the docs pointer borrows the bytes.
Honesty
- A why-not is summarized from the record, not quoted.
- The per-source number is a binding cosine — relevance, not confidence.
no_recorded_rulingis first-class: it means unknown, not approval.- lema never depicts a capability that doesn’t fire on a real record. Fuse rulings covered today: React, Kubernetes, Rust, Vue, Go, and Ethereum EIPs.
Try it
Name an approach — no signup.
Check a direction against React, Kubernetes, Rust, Vue, Go, or Ethereum EIPs and see the live verdict. The same check is available to agents as the check_approach tool.
Citations point to each project’s public RFC, KEP, proposal, or EIP record. lema is not affiliated with React, Kubernetes, Rust, Vue, Go, or Ethereum EIPs.