Intelligence

ContractRadar

Machine change-governance: a ~200-byte hash poll detects any contract drift, then localises it to a JSON Pointer, classifies it breaking / minor / cosmetic, and routes it — automatically.

Contracts watched

5 · demo

Open breaking

Changes recorded

Daily watch cost

≈200 B /contract

Radar

Contracts under watch · 5

Service	Rev	Fingerprint (L0)	Fields	Last change	Seen
Payment payment	v3	sha256:5dbad8eaed…	3/4	breaking	demo10s ago
Order Management order-management	v2	sha256:603a984092…	4/4	breaking	demo10s ago
Shipment Tracking shipment-tracking	v2	sha256:bf0edf001a…	2/4	minor	demo10s ago
Billing Account billing-account	v2	sha256:1e62cc5b02…	2/3	cosmetic	demo10s ago
Customer Account customer-account	v2	sha256:71185ac338…	1/2	minor	demo10s ago

Change feed

Detected · localised · classified · routed

paymentbreakingpagedv71d ago
- breakingdomain-changedrange [0, 1000000] → [0, 500000]#/components/schemas/payment/properties/amount
sha256:a74dae8d54… → sha256:5dbad8eaed…
customer-accountminorloggedv62d ago
- minorenum-value-addedenum += 'enterprise'#/components/schemas/customer-account/properties/segment
sha256:c6dca59d5b… → sha256:71185ac338…
billing-accountcosmeticsuppressedv53d ago
acknowledged
- cosmeticmeaning-changedbusiness meaning edited#/components/schemas/billing-account/properties/amount/description
sha256:65de0ff161… → sha256:1e62cc5b02…
shipment-trackingminorloggedv44d ago
- minorfield-addednew optional field 'trackingRef'#/components/schemas/shipment-tracking/properties/trackingRef
sha256:4602839da6… → sha256:bf0edf001a…
order-managementbreakingpagedv35d ago
- breakingfield-now-required'channel' became required#/components/schemas/order-management/required
sha256:c81d159a66… → sha256:603a984092…
paymentbreakingpagedv26d ago
- breakingenum-value-removedenum -= 'rate_limit'#/components/schemas/payment/properties/action
sha256:a74dae8d54… → sha256:b8d74dbd80…

Governance

Routing policy

breaking

Removed enum / required field / type change — pages the on-call.

minor

Additive: new optional field, new enum value — logged to the channel.

cosmetic

Meaning / scenario / title edits — suppressed (no noise).

Alert channel

Breaking changes notify consumers via webhook + Deprecation/Sunset headers (RFC 8594) and the X-API-Change-Level response header.

Provider

Live sandbox radar

ContractRadar consumes the Companion Sandbox's L0/L1/L2 change-governance surface.

Provider radar (JSON) ↗Machine metadata document ↗Remote-URL spec watches (Change Intelligence) →

Phase 0 · L0

Fingerprint Lab — how the ~200-byte radar works

A whole API spec — paths, schemas, enums, the lot — is reduced to one canonical SHA-256 (servers stripped so a redeploy doesn't flip it). That hash is the entire L0 payload. To ask "did anything change?" you send the hash as an If-None-Match ETag: unchanged → 304 with an empty body; changed → a fresh ~200-byte L0, and only then do you pull L1/L2. Edit the spec below and Poll to watch it drift.

OpenAPI spec (editable)

{
  "openapi": "3.1.0",
  "info": { "title": "Orders API", "version": "2.4.1" },
  "servers": [{ "url": "https://api.acme.io" }],
  "paths": {
    "/orders": {
      "post": {
        "summary": "Create an order",
        "requestBody": { "content": { "application/json": { "schema": { "$ref": "#/components/schemas/OrderCreate" } } } },
        "responses": { "201": { "description": "created" } }
      }
    },
    "/orders/{id}": {
      "get": { "summary": "Get an order", "responses": { "200": { "description": "ok" } } }
    }
  },
  "components": {
    "schemas": {
      "OrderCreate": {
        "type": "object",
        "required": ["customerId", "currency", "items"],
        "properties": {
          "customerId": { "type": "string" },
          "currency": { "type": "string", "enum": ["EUR", "USD", "HUF", "GBP"] },
          "channel": { "type": "string", "enum": ["web", "mobile", "pos", "partner"] },
          "items": { "type": "array", "items": { "type": "object" } }
        }
      }
    }
  }
}

L0 response (the whole payload)

{
  "api": "Orders API",
  "version": "2.4.1",
  "schemaHash": "sha256:5c4617bcf9dc80ababfbec299942c951751dd791a7cddb98c521e2403733064e"
}

L0 payload

125 B

Full spec

1019 B

Saved per poll

87.7%

The L0 stays ~125 bytes no matter how big the spec is — a 2 KB or a 2 MB spec both fingerprint to the same fixed size. And an unchanged poll is a 304 with a 0-byte body. That is the whole "200 bytes a day" cost.

Poll timeline

Press Poll L0 to baseline, press again (unchanged → 304), then edit the spec and Poll again to see drift detected from a 200-byte hash.

Why ContractRadar

Stop shipping silent API breaks

A partner narrows one enum, makes one field required, changes one type — and three integrations break in production weeks later. ContractRadar makes that impossible to miss: it watches every contract for a couple of hundred bytes a day and turns any drift into a dated, localised, severity-graded, machine-readable event.

Detect

A ~200-byte L0 hash poll (ETag/304) flips the instant any byte of the contract moves.

Localise

L1 Merkle fingerprints + L2 diff pin the change to an exact RFC-6901 JSON Pointer.

Classify

Every move is graded breaking / minor / cosmetic — no human reads a diff.

Notify

Breaking pages the on-call; consumers get versioned headers + a machine changelog.

≈ 200 B

per contract, per day — the entire watch cost (L0 hash, ETag/304).

3 levels

breaking / minor / cosmetic routing, so only real breaks page anyone.

100% machine

detect → localise → classify → notify; only the DECISION stays human.

How it compares

Capability	ContractRadar	Manual changelog	oasdiff in CI	Uptime monitor
Catches a one-word / enum / domain change
Localises to an exact JSON Pointer
Classifies severity automatically
Auto-signals consumers (webhook + headers)
Zero manual changelog writing
Daily watch cost ≈ 200 bytes

full · partial / manual · none