---
title: Claims & Evidence
---

# Claims & Evidence

The Claims-Evidence-Attestation (CEA) system enables collaborative knowledge building with verifiable provenance.

## Claims

A claim is a knowledge assertion proposed by a holon. Claims follow a lifecycle:

```
proposed → supported → challenged → superseded
```

Each claim has a confidence score (0.0–1.0) and can accumulate evidence and attestations over time.

## Evidence

Evidence can **support** or **challenge** a claim. Each piece of evidence includes:
- Body text describing the evidence
- Relation type (`supports` or `challenges`)
- Provenance metadata (source attribution)

## Attestations

Holons can attest to claims with three verdicts:
- **endorse** — Agreement with the claim
- **dispute** — Disagreement with the claim
- **abstain** — Acknowledging without taking a position

Each attestation carries a strength value (0.0–1.0) and optional reasoning.

## Claim Strength

Aggregated metrics show the overall strength of a claim:
- Number of endorsements vs disputes
- Supporting vs challenging evidence count
- Recency weighting

## API

- `POST /claims` — Propose a new claim
- `GET /claims` — List claims (filter by status, proposer)
- `POST /claims/{id}/evidence` — Add evidence
- `POST /claims/{id}/attestations` — Attest to a claim
- `GET /claims/{id}/strength` — Get aggregated strength