Capability-Grounded Reputation (CGR)
CGR is available in the GRAFOMEM Cloud platform. It is an early layer — the model and endpoints are live, but the reputation layer is new and evolving. Read it as a working foundation, not as a production-scale, high-volume service.
CGR builds a per-(agent, domain) reputation grounded only in resolved
outcomes. Its guiding principle is "verify the reviewer, not the task." — an agent
(or a reviewer) earns standing by being right about things that later turn out to be
checkable, not by asserting confidence.
CGR sits on top of the governed memory foundation: governed decisions, their outcomes, and peer reviews are recorded as facts, and reputation is computed from them. It adds nothing you have to trust blindly — every score traces back to resolved evidence.
The model
Reputation for one (agent, domain) is a Beta(α, β) posterior:
- Neutral prior — every agent starts at
α = β = 1(no unearned standing). - Score — the posterior mean,
E = α / (α + β). - Confidence — the evidence mass,
n = α + β: the resolved-observation count plus the neutral prior's two pseudo-counts (so 22 resolved observations report a confidence of 24).
Score and confidence are always reported together. A high score on one resolved outcome is not the same as a high score on hundreds — and CGR never lets you read the first as if it were the second.
Judgment-only
CGR scores judgment calls — decisions an agent certifys that are tagged as
judgment. Rote or deterministic actions earn nothing: following a fixed rule is not
a capability signal, so it does not move the posterior.
Confidence-gating
Thin-evidence scores are discounted or withheld. Until an agent has accumulated enough resolved outcomes, its score is treated as provisional rather than dependable — so a newcomer cannot present a lucky early result as an established track record.
Two channels
Reputation is fed by two channels with deliberately different trust rules:
| Channel | Source | Gating |
|---|---|---|
| Verifiable | resolved outcomes (the world confirmed or refuted the call) | ungated — direct evidence |
| Review | peer review of a decision | gated — a review is only as good as the reviewer |
The verifiable channel is direct evidence and needs no gate. The review channel is where reputation is easiest to game — so it is gated.
The review gate (Sybil resistance)
Each reviewer carries a calibration weight w ∈ [0, 1], itself earned on verifiable
outcomes. A review's contribution is scaled by a soft ramp:
g(w) = max(0, (w − τ) / (1 − τ))
- A reviewer at or below the threshold
τcontributes nothing; contribution ramps linearly to full weight asw → 1. - A per-source cap
Kbounds how much any single reviewer can move a score. - An unknown / uncalibrated reviewer fails closed — no calibration weight means no contribution, so spinning up fresh reviewer identities buys nothing.
τ and K are per-tenant configurable. (Illustrative defaults exist, but they are
configuration, not fixed law — tune them to your own risk posture.)
Tenant isolation
Each tenant's reputation is isolated — one tenant's agents, reviews, and calibration never influence another's scores.
What gets recorded
Governed decisions, their resolved outcomes, and peer reviews are written as append-only, content-addressed facts in your tenant's governed memory store (latest valid record wins; nothing is destructively overwritten).
Separately, reputation-authority events — reviewer-calibration updates and issued reputation attestations — are recorded on GRAFOMEM's signed, append-only audit chain. (The raw outcome and review facts themselves are stored append-only in the memory store, not individually placed on that signed chain.)
Independently reproducible
The scoring model is documented and independently reproducible. cgr-bench reproduces its properties from source: cold-start and Sybil-resistance behavior asserted in CI, an early-warning signal of −0.997 against real credit-default outcomes at 25% resolution, and reviewer calibration that beats a naive equal-weight crowd by ~14% out-of-sample on ~1,900 real human forecasters (held-out reliability recovery r ≈ 0.5–0.65 across split designs).
Every number above reproduces from make reproduce; where a reconstruction lands below
an originally recorded value, the benchmark reports the reproduced number.
Concepts
Canonical explanations of the ideas behind CGR — the retrievable, citable answers to "what is capability-grounded reputation?" and related questions:
- What is Capability-Grounded Reputation? — the pillar: definition, the problem, the formal model, a worked example, and limitations.
- Outcome-grounded reputation — assertion vs. resolution; judgment-only scoring; what counts as a resolvable outcome.
- Reviewer calibration & Sybil resistance — the review gate, per-source cap, fail-closed behavior, and the benchmark results.
- Evidence mass & uncertainty — why score and evidence mass travel together, and the evidence-gated ceiling.
- The capability graph (concept) — the evidence-backed network the accumulated outcomes point toward. A direction, not a shipped product.
- CGR FAQ — short answers to the most common questions.
Next
- CGR API Reference — record governed decisions, outcomes, and reviews; read reputation scores; and how these endpoints differ from the Decision Trail and the Governance Gateway.