> ## Documentation Index
> Fetch the complete documentation index at: https://docs.peaq.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Machine Credit Rating

> A Moody's-style score that summarizes a machine's creditworthiness from its on-chain history.

Machine Credit Rating (MCR) is a letter rating, modeled on traditional credit agencies, that summarizes a machine's financial standing from its on-chain history.

Any application can query a machine's MCR through the public [MCR API](/peaqos/api-reference/overview): no authentication, no permissions. It travels with the machine across chains.

## Rating scale

MCR ratings use a familiar AAA-to-NR scale. The integer `mcr_score` (0-100, rounded) maps to a letter via fixed thresholds:

| Rating          | `mcr_score` | Meaning                                            |
| :-------------- | :---------- | :------------------------------------------------- |
| **AAA**         | ≥ 95        | Highest credit quality                             |
| **AA**          | ≥ 85        | Very high credit quality                           |
| **A**           | ≥ 75        | High credit quality                                |
| **BBB**         | ≥ 60        | Investment grade                                   |
| **BB**          | ≥ 45        | Below investment grade                             |
| **B**           | ≥ 30        | Minimum rated                                      |
| **NR**          | 0           | Not rated. Score below 30, or machine is unbonded  |
| **Provisioned** | 0           | Newly registered. Not enough history to score yet. |

Both `NR` and `Provisioned` return `mcr_score = 0`; the `mcr` letter and `bond_status` field on `/mcr/{did}` distinguish the two.

## Lifecycle: Provisioned graduation

A freshly registered, bonded machine is **Provisioned**: on-chain, but not yet rated. It graduates onto the rated scale once it has both:

* **Enough events:** a sustained set of qualifying events. Activity-only machines (sensors, drones without revenue) can graduate via activity alone; revenue is not required.
* **Enough history:** the first-to-last event span covers a sustained operating window.

Until both gates are cleared the machine returns `mcr: "Provisioned"` with `mcr_score: 0`, regardless of how strong the underlying activity is.

Ratings are not assigned. They're earned. A machine's standing reflects what it has done on-chain.

## How the score is computed

The MCR server fetches every event from the `EventRegistry`, normalizes revenue values to USD cents via FX at the event's timestamp, and combines them into a `0`–`100` integer score that maps to a letter rating. The exact weighting is not published.

The score is built from a small set of inputs:

**Bond.** Every bonded machine receives a baseline contribution. An unbonded machine returns `(0, "NR")` immediately. Bond is the floor for any score at all.

**Revenue and activity.** Two factors derived from the event history. Each rewards consistency (regular cadence), depth (sustained activity over many events), and tenure (longer-running machines). Revenue is daily-aggregated: events are summed per UTC calendar day, and only days that meet a minimum economic threshold count toward revenue.

**Trust level.** Per-event trust tiers, with revenue events weighted by economic value. Higher tiers contribute more; `0` self-reported, `1` on-chain verifiable, `2` hardware-signed. See [Trust levels](/peaqos/concepts/trust-levels).

A long-running self-reported machine earns a small graduation bonus on its trust contribution after sustained operation, but it remains below the on-chain tier.

**Freshness.** Recency decay applied to the trust contribution. A machine that hasn't reported recently scores progressively lower; a sustained dormancy gap clamps freshness at a floor until the machine demonstrates renewed activity over a recovery window. Recovery is earned, not granted by a single recent event.

**Negative event flag.** While an active flag is set on the machine, the trust contribution is reduced for a fixed window from the flag timestamp; the penalty expires automatically after the window closes.

The final score is clamped to `[0, 100]` and rounded to an integer before mapping to a letter.

## Revenue trend

`/mcr/{did}` exposes a `revenue_trend` field with one of four values, derived from short-term vs longer-term moving averages over qualifying revenue events:

| Value            | Meaning                                                     |
| :--------------- | :---------------------------------------------------------- |
| `"up"`           | Recent revenue is materially above the longer-term baseline |
| `"stable"`       | Recent revenue tracks the longer-term baseline              |
| `"down"`         | Recent revenue is materially below the longer-term baseline |
| `"insufficient"` | Not enough qualifying revenue events to compute a trend     |

## Multi-currency revenue

Revenue events submitted in any ISO 4217 currency get FX-normalized to USD by the MCR server before scoring. Pass `currency` directly to `submitEvent` and supply `value` as the currency's minor-unit integer (cents for USD/HKD, whole units for JPY/KRW); the server fetches the historical rate at the event's `timestamp` and stores both `origin_value` and the computed `usd_value` (USD cents). Two distinct degradation paths show up on the wire:

* **Unsupported currency.** The per-event `amount_status` becomes `"unsupported_currency"`. The revenue value is ignored when scoring (treated as \$0). This is a partner-input error, not infra failure, so it does **not** flip `mcr_degraded`.
* **FX infrastructure failure.** When the MCR server has to fall back to a stale snapshot (`fx_source = "stale_latest"`) or has no FX at all (`fx_source = "default_usd_fx_outage"`), the event's `amount_status` becomes `"fx_unavailable"` **and** the top-level `mcr_degraded: true` flag flips on `/mcr/{did}`, so consumers can distinguish a degraded score from a quiet machine.

See [Submit events: currency and value units](/peaqos/guides/submit-events#currency-and-value-units).

## Cross-links

* [Events](/peaqos/concepts/events): the revenue and activity records that feed MCR
* [Trust levels](/peaqos/concepts/trust-levels): what each `trust_level` means at submit time
* [GET /mcr/\{did}](/peaqos/api-reference/get-mcr): fetch a machine's current rating
* [Qualify function](/peaqos/functions/qualify): the function that exposes MCR end-to-end