# Sprint 91 Plan: Ecosystem Marketplace and Trust Exchange

## Context

With plugin and standards foundations in place, Sprint 91 introduces a curated
marketplace for adapters, verifiers, and policy packs.

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## Goals

1. Add discoverable marketplace metadata and search
2. Enforce trust tiers for published ecosystem artifacts
3. Provide usage/quality signals for artifact selection
4. Prevent unsafe artifact promotion in production pathways

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## Steps

### Step 1139: Marketplace catalog schema (12 tests)
### Step 1140: Artifact trust-tier model (`community`, `verified`, `certified`) (10 tests)
### Step 1141: Artifact quality scoring and ranking engine (10 tests)
### Step 1142: Supply-chain integrity checks for marketplace artifacts (10 tests)
### Step 1143: Artifact de-listing and quarantine workflow (10 tests)
### Step 1144: Marketplace policy bindings for tenants (8 tests)
### Step 1145: `whetstone_marketplace_search` MCP tool (8 tests)
### Step 1146: `whetstone_get_artifact_trust_report` MCP tool (8 tests)
### Step 1147: Marketplace governance report artifact (8 tests)
### Step 1148: Sprint 91 integration summary + regression (8 tests)

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## Trust Rule

- Non-certified artifacts cannot be auto-enabled for Stable-tier workflows.