The problem
Why SCI exists.
Self-reported skills are unreliable. LinkedIn endorsements are traded as favors. Certifications prove you passed a test once, not that you can do the work today.
SCI solves this by computing credibility from verifiable evidence — sessions completed, assessments passed, peers who vouch for you, and external proofs attached. Every point is earned, not claimed.
How it's calculated
Four signals. One score.
Peer sessions
Completed sessions, partner ratings, and teaching quality contribute the largest share of your SCI score.
AI assessments
Pass rates, difficulty levels, and consistency across assessments demonstrate verified competence.
External proofs
Certificates, portfolio items, and third-party validations add independent credibility to your score.
Peer reviews
Endorsements and feedback from learning partners provide social proof weighted by the endorser's own SCI.
Tier system
Six tiers of credibility.
Claimed
0Self-declared skill with no evidence. The starting point for every skill you add to your passport.
Newcomer
1-299At least one completed session or assessment. You have begun building evidence for this skill.
Proven
35-54Multiple sessions with positive ratings. Consistent performance across different learning contexts.
Verified
55-74Passed AI assessments at intermediate level. Peer endorsements from verified partners confirm your ability.
Expert
75-89High pass rates on advanced assessments. Teaching sessions where you helped others learn effectively.
Authority
90-100Sustained excellence across all evidence types. External proofs, top-tier assessments, and strong peer network.
Score composition
Four evidence sources — sessions, assessments, external proofs, and peer reviews — each with defined weight.
Tier progression
Move through six credibility tiers as you accumulate evidence. Each tier requires stronger proof.
Evidence types
Session completions, AI assessment scores, peer endorsements, and external certificates all count.
GET /api/v1/verify/skill
{ "score": 84, "tier": "Expert" }
API access
Employers query SCI scores through a REST API. Each score comes with a full evidence breakdown.
Score dynamics
A living score.
Your SCI grows when you complete sessions, pass assessments, receive endorsements, and attach external proofs. Each evidence type has a defined weight.
Inactivity causes gradual decay. A score earned six months ago is worth less than one earned last week. This ensures SCI reflects current ability, not past achievements.
Gaming is structurally impossible. Evidence comes from completed sessions with real people, AI-graded assessments, and verified external sources. No self-reporting, no favor trading.
For employers
Verify skills instantly.
Employers can query any candidate's SCI score through our API. Each score comes with a full evidence breakdown — which sessions contributed, which assessments were passed, and who endorsed the candidate.
No more guessing from resumes. No more take-home tests that take days. SCI gives you a verified, up-to-date picture of a candidate's actual abilities in seconds.
GET /api/v1/verify/skill
{
"user": "alex-chen",
"skill": "react"
}
Trust guarantees
Every point is explainable.
SCI is not a black box. Every factor in your score is visible, every piece of evidence is traceable, and every change is logged in your event history.
Transparent
Every factor in your SCI score is visible. You can see exactly which sessions, assessments, and proofs contribute to your tier.
Tamper-proof
All evidence is append-only and event-sourced. Once recorded, proof cannot be altered or deleted — only new evidence can be added.
Portable
Your SCI score travels with your passport. Employers verify it via API, and it works across any platform that integrates with Lemma.
Comparison
SCI vs the alternatives.
| Feature | Lemma SCI | Certifications | Self-assessment | |
|---|---|---|---|---|
| Verifiable evidence trail | ||||
| Real-time score updates | ||||
| Tamper-proof records | ||||
| Granular skill breakdown | ||||
| Recency-weighted scoring | ||||
| API access for verification |
Transparent
Every factor in your score is visible. See exactly which evidence contributes to your tier.
Tamper-proof
All evidence is append-only and event-sourced. Once recorded, it cannot be altered.
Portable
Your SCI travels with your passport. Verify via API across any platform.
Getting started
Start learning with peers
Join Lemma to find skill-matched partners, complete sessions, and build a verified portfolio — all for free.
Maya R.
94% match · React & Python
Build with our API
Integrate Lemma's skill verification into your hiring pipeline, LMS, or talent platform with our REST API and SDKs.
Start proving what you know.
Early access is rolling out for individuals and teams. No credit card, no PDFs — just the things you made, made visible.