Economicocontracts.change_quantity
What it does
Record an evidenced absolute seat or quantity count under the right’s declared proration and decrease rules. expectedQuantity must match the count in force.
An optional bill records the charge atomically at its invoicedAmount on the right’s declared price basis (before reductions, and before tax for exclusive treatment), the vendor’s for a received right or the business’s own for a provided one; an amount other than the frozen proration flags attention.priceDiffers. bill.taxAmount states the invoice tax in minor units, including zero; supplier tax uses that figure, with tax_differs review attention when it differs from derivation.
A received exclusive-tax seat-change charge with positive supplier tax, a stated invoicedAmount and no stated tax raises tax_amount_unconfirmed when the amount matches predicted price plus tax within one minor unit, or when proration is stated without an independent prediction. It is recorded as entered; bill.usageReviewItems returns the frozen review item, including on duplicate replays.
Before you send it
An authorized OAuth connection may call it, including a headless client. Effective membership, application grant and token permissions still apply. Describe contracts.change_quantity through GET /v1/catalog/commands/{name} before acting.
The envelope may reference a registered source document of kind source_document, activity_statement, contract; this is separate from any evidence required by the input.
Inputs
Put these fields inside the envelope’s input object. The outer envelope names the command, a stable idempotency_key and effective_at; request and recovery rules explain those separately. Use exact minor-unit integer strings for monetary fields. Take existing IDs from prior reads or command results; choose a new identity only where the command asks for one.
Required means required within its containing object; an optional parent can be omitted.
| Field | Type | Required | Meaning and accepted values |
|---|---|---|---|
contractId | string | Yes | Minimum length: 1. Example: "ctr_example". |
activityKey | string | Yes | Minimum length: 1. Example: "seats". |
sourceFactId | string | Yes | Minimum length: 1. Example: "admin:seat-change". |
requestedAt | string | Yes | Format: date-time. Minimum length: 1. Example: "2026-10-20T00:00:00Z". |
expectedQuantity | string | Yes | Pattern: "^(0|[1-9][0-9]*)$". Example: "5". |
quantity | string | Yes | Pattern: "^(0|[1-9][0-9]*)$". Example: "7". |
evidence | object | Yes | |
evidence.service | array | Yes | Items: object. Minimum items: 1. Maximum items: 20. |
evidence.service[].kind | string | Yes | Choose "tap_message", "x402_receipt", "chain_tx", "signed_doc", "stripe_object", "other". Example: "other". |
evidence.service[].ref | string | Yes | Minimum length: 1. Example: "admin-log". |
evidence.service[].signer | string | No | Minimum length: 1. |
bill | object | No | |
bill.sourceFactId | string | Yes | Minimum length: 1. |
bill.evidence | array | Yes | Items: object. Minimum items: 1. Maximum items: 20. |
bill.evidence[].kind | string | Yes | Choose "tap_message", "x402_receipt", "chain_tx", "signed_doc", "stripe_object", "other". |
bill.evidence[].ref | string | Yes | Minimum length: 1. |
bill.evidence[].signer | string | No | Minimum length: 1. |
bill.invoicedAmount | string | Yes | Pattern: "^(0|[1-9][0-9]*)$". |
bill.taxAmount | string | No | Pattern: "^(0|[1-9][0-9]*)$". |
bill.dueDate | string | No | Format: date. Minimum length: 1. |
After acceptance
When the command emits events, its documented effects and receipt are recorded in the command transaction. The response returns commandId, replayed, the command-specific result below and emitted events with their IDs and CIDs. A command is not automatically a cash movement or revenue recognition: use the behavior above to determine what this command records.
Inspect result and the affected records or reports before continuing. Save returned identifiers for later calls. Fetch GET /v1/commands/{id} with commandId to recover the accepted receipt; retry the same intent with the same idempotency key if the response was lost. Some commands can succeed with events: [] and return a transient result and commandId without persisting a receipt. A lookup of that ID can return null; retain the returned result and verify the affected record. Retrying can re-evaluate the current state rather than replay a stored result. A domain no_change is a separate success outcome with no persisted receipt.
Result fields
Required means required within its containing object; an optional parent can be omitted.
| Field | Type | Required | Meaning and accepted values |
|---|---|---|---|
changeId | string | Yes | Minimum length: 1. |
adjustment | object | No | |
credit | object | No | |
bill | object | No |
All commands · Operation and errors · Reusable schemas
Keep credentials out of prompts; rehearse writes only in a disposable sandbox.
Exact request schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"name": {
"const": "contracts.change_quantity"
},
"input": {
"type": "object",
"additionalProperties": false,
"required": [
"contractId",
"activityKey",
"sourceFactId",
"requestedAt",
"expectedQuantity",
"quantity",
"evidence"
],
"properties": {
"contractId": {
"type": "string",
"minLength": 1
},
"activityKey": {
"type": "string",
"minLength": 1
},
"sourceFactId": {
"type": "string",
"minLength": 1
},
"requestedAt": {
"type": "string",
"minLength": 1,
"format": "date-time"
},
"expectedQuantity": {
"type": "string",
"pattern": "^(0|[1-9][0-9]*)$"
},
"quantity": {
"type": "string",
"pattern": "^(0|[1-9][0-9]*)$"
},
"evidence": {
"type": "object",
"additionalProperties": false,
"properties": {
"service": {
"type": "array",
"minItems": 1,
"maxItems": 20,
"items": {
"type": "object",
"additionalProperties": false,
"properties": {
"kind": {
"enum": [
"tap_message",
"x402_receipt",
"chain_tx",
"signed_doc",
"stripe_object",
"other"
]
},
"ref": {
"type": "string",
"minLength": 1
},
"signer": {
"type": "string",
"minLength": 1
}
},
"required": [
"kind",
"ref"
]
}
}
},
"required": [
"service"
]
},
"bill": {
"type": "object",
"additionalProperties": false,
"properties": {
"sourceFactId": {
"type": "string",
"minLength": 1
},
"evidence": {
"type": "array",
"minItems": 1,
"maxItems": 20,
"items": {
"type": "object",
"additionalProperties": false,
"properties": {
"kind": {
"enum": [
"tap_message",
"x402_receipt",
"chain_tx",
"signed_doc",
"stripe_object",
"other"
]
},
"ref": {
"type": "string",
"minLength": 1
},
"signer": {
"type": "string",
"minLength": 1
}
},
"required": [
"kind",
"ref"
]
}
},
"invoicedAmount": {
"type": "string",
"pattern": "^(0|[1-9][0-9]*)$"
},
"taxAmount": {
"type": "string",
"pattern": "^(0|[1-9][0-9]*)$"
},
"dueDate": {
"type": "string",
"minLength": 1,
"format": "date"
}
},
"required": [
"sourceFactId",
"evidence",
"invoicedAmount"
]
}
}
},
"idempotency_key": {
"type": "string",
"minLength": 1,
"maxLength": 256
},
"effective_at": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z))$"
},
"source_document_id": {
"description": "A registered document of kind source_document, activity_statement, contract that caused this command.",
"type": "string",
"minLength": 1
}
},
"required": [
"name",
"input",
"idempotency_key",
"effective_at"
],
"additionalProperties": false
}Accepted command receipt
{
"type": "object",
"required": [
"commandId",
"replayed",
"result",
"events"
],
"properties": {
"commandId": {
"type": "string"
},
"replayed": {
"type": "boolean"
},
"imported": {
"const": true,
"description": "The command's events are history from before the business joined Economico, recorded as an import: free of monthly events."
},
"result": {
"type": "object",
"properties": {
"changeId": {
"type": "string",
"minLength": 1
},
"adjustment": {
"type": "object"
},
"credit": {
"type": "object"
},
"bill": {
"type": "object"
}
},
"required": [
"changeId"
]
},
"events": {
"type": "array",
"items": {
"type": "object",
"properties": {
"id": {
"type": "integer"
},
"cid": {
"type": "string"
}
}
}
}
}
}Example request
{
"name": "contracts.change_quantity",
"input": {
"contractId": "ctr_example",
"activityKey": "seats",
"sourceFactId": "admin:seat-change",
"requestedAt": "2026-10-20T00:00:00Z",
"expectedQuantity": "5",
"quantity": "7",
"evidence": {
"service": [
{
"kind": "other",
"ref": "admin-log"
}
]
}
},
"effective_at": "2026-09-01T00:00:00Z",
"idempotency_key": "contracts.change_quantity-example-0"
}