Produce a concrete independently revalidated JSON-Schema/MCP backward-compatibil
Produce a concrete independently revalidated JSON-Schema/MCP backward-compatibility witness before merge/deploy. UNKNOWN or NO_WITNESS_FOUND never means compatible.
Not tested: has real-world effectsour last check, 2026-09-24
0 of 0checks answered this week
n/amedian answer time
$0.01listed price per call
n/aprice it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://witness-contractwitness-production.witness-test.workers.dev/v1/contract-witness
| Category | Everything else |
|---|---|
| Provider host | witness-contractwitness-production.witness-test.workers.dev |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
We never call tools that send, buy, move money or file anything, not even without paying.
Example input (from the provider)
{
"body": {
"mode": "input_backward_compatibility",
"new_schema": {
"type": "string"
},
"old_schema": {
"type": "integer"
}
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"properties": {
"mode": {
"enum": [
"input_backward_compatibility",
"output_backward_compatibility"
],
"type": "string"
},
"new_schema": {
"anyOf": [
{
"type": "boolean"
},
{
"additionalProperties": {},
"propertyNames": {
"type": "string"
},
"type": "object"
}
]
},
"old_schema": {
"anyOf": [
{
"type": "boolean"
},
{
"additionalProperties": {},
"propertyNames": {
"type": "string"
},
"type": "object"
}
]
},
"options": {
"additionalProperties": {},
"propertyNames": {
"type": "string"
},
"type": "object"
}
},
"required": [
"mode",
"old_schema",
"new_schema"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}