POST /api/v1/buyer/sessions/{id}/turns/{requestId}/complete
Settle the current buyer reasoning turn
Stores bounded conversation state only if the turn revision remains active. Cancellation prevents late completion. Completion does not settle provider attempts or approve commercial actions.
Authenticated and advertiser scoped. Cross-tenant resource access returns 404. Product/channel entitlements also apply.
The request schema is generated from the runtime Zod input validator. Cross-field refinements and state-dependent constraints are additionally enforced by the API.
Request
HTTP
POST /api/v1/buyer/sessions/{id}/turns/{requestId}/completeUse the configured API origin. Private requests require a verified Bearer credential; an agent mutation can additionally require exact approval headers. Authentication guide →
| Parameter | Location | Required | Description |
|---|---|---|---|
id | path | Yes | |
requestId | path | Yes |
Parameter schemas
JSON Schema
[
{
"name": "id",
"in": "path",
"required": true,
"schema": {
"type": "string",
"format": "uuid"
}
},
{
"name": "requestId",
"in": "path",
"required": true,
"schema": {
"type": "string",
"format": "uuid"
}
}
]Request body contract
{
"required": true,
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"expectedRevision": {
"type": "integer",
"exclusiveMinimum": 0
},
"status": {
"type": "string",
"enum": [
"completed",
"failed"
]
},
"message": {
"type": "string",
"minLength": 1,
"maxLength": 16000
},
"history": {
"type": "array",
"items": {
"type": "object",
"additionalProperties": {}
},
"maxItems": 128
},
"toolCalls": {
"type": "array",
"items": {
"type": "object",
"properties": {
"tool": {
"type": "string",
"pattern": "^[a-z][a-z0-9_]{0,119}$"
},
"status": {
"type": "string",
"enum": [
"completed",
"failed"
]
}
},
"required": [
"tool",
"status"
],
"additionalProperties": false
},
"maxItems": 64,
"default": []
},
"references": {
"type": "array",
"items": {
"type": "object",
"properties": {
"kind": {
"type": "string",
"enum": [
"persona",
"plan",
"campaign",
"creative",
"asset",
"mission",
"run"
]
},
"id": {
"type": "string",
"minLength": 1,
"maxLength": 128
}
},
"required": [
"kind",
"id"
],
"additionalProperties": false
},
"maxItems": 32,
"default": []
}
},
"required": [
"expectedRevision",
"status",
"message"
],
"additionalProperties": false
}
}
}
}Responses
Reference schemas resolve through the downloadable OpenAPI components. The specification marks unmodeled success payloads; an unrestricted payload is not a promise that arbitrary fields exist.
400Invalid request or unsupported fields
Response contract
{
"description": "Invalid request or unsupported fields",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}401Missing or invalid authentication
Response contract
{
"description": "Missing or invalid authentication",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}403Permission or product scope refused
Response contract
{
"description": "Permission or product scope refused",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}404Route or tenant-scoped resource not found
Response contract
{
"description": "Route or tenant-scoped resource not found",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}409State, revision, approval, funding or idempotency conflict
Response contract
{
"description": "State, revision, approval, funding or idempotency conflict",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}422Supplier configuration, capability or upstream refusal
Response contract
{
"description": "Supplier configuration, capability or upstream refusal",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}429Rate limit reached; wait before retrying
Response contract
{
"description": "Rate limit reached; wait before retrying",
"headers": {
"x-ratelimit-limit": {
"description": "Maximum requests permitted in the current rate-limit window.",
"schema": {
"type": "integer"
}
},
"x-ratelimit-remaining": {
"description": "Requests remaining in the current window.",
"schema": {
"type": "integer"
}
},
"x-ratelimit-reset": {
"description": "Seconds until the current rate-limit window resets.",
"schema": {
"type": "integer"
}
},
"retry-after": {
"description": "Minimum seconds to wait before retrying.",
"schema": {
"type": "integer"
}
}
},
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}500Internal error; inspect state before retrying a mutation
Response contract
{
"description": "Internal error; inspect state before retrying a mutation",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}503Dependency or authentication verifier unavailable
Response contract
{
"description": "Dependency or authentication verifier unavailable",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}2XXSuccessful response.
Response contract
{
"description": "Successful response.",
"headers": {
"x-ratelimit-limit": {
"description": "Maximum requests permitted in the current rate-limit window.",
"schema": {
"type": "integer"
}
},
"x-ratelimit-remaining": {
"description": "Requests remaining in the current window.",
"schema": {
"type": "integer"
}
},
"x-ratelimit-reset": {
"description": "Seconds until the current rate-limit window resets.",
"schema": {
"type": "integer"
}
}
},
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"session": {
"type": "object",
"properties": {
"id": {
"type": "string",
"format": "uuid"
},
"workflow": {
"type": "string",
"enum": [
"brief_to_plan",
"creative_direction",
"campaign_review",
"launch_assistance"
]
},
"context": {
"type": "object",
"properties": {
"campaignId": {
"type": "string",
"minLength": 1,
"maxLength": 128
},
"planId": {
"type": "string",
"minLength": 1,
"maxLength": 128
},
"personaId": {
"type": "string",
"minLength": 1,
"maxLength": 128
},
"creativeId": {
"type": "string",
"minLength": 1,
"maxLength": 128
}
},
"additionalProperties": false
},
"revision": {
"type": "integer",
"exclusiveMinimum": 0
},
"activeTurnId": {
"anyOf": [
{
"type": "string",
"format": "uuid"
},
{
"type": "null"
}
]
},
"status": {
"type": "string",
"enum": [
"running",
"idle"
]
},
"messages": {
"type": "array",
"items": {
"type": "object",
"properties": {
"role": {
"type": "string",
"enum": [
"user",
"assistant"
]
},
"message": {
"type": "string"
},
"requestId": {
"type": "string",
"format": "uuid"
}
},
"required": [
"role",
"message",
"requestId"
],
"additionalProperties": false
},
"maxItems": 40
},
"history": {
"type": "array",
"items": {
"type": "object",
"additionalProperties": {}
},
"maxItems": 128
},
"productScope": {
"type": "object",
"properties": {
"product": {
"type": "string",
"enum": [
"adbuymcp",
"doohmcp",
"ctvmcp"
]
},
"channels": {
"type": "array",
"items": {
"type": "string",
"enum": [
"ctv",
"audio",
"tv",
"cinema",
"dooh",
"search",
"social"
]
},
"minItems": 1,
"maxItems": 7
}
},
"required": [
"product",
"channels"
],
"additionalProperties": false
},
"references": {
"type": "array",
"items": {
"type": "object",
"properties": {
"kind": {
"type": "string",
"enum": [
"persona",
"plan",
"campaign",
"creative",
"asset",
"mission",
"run"
]
},
"id": {
"type": "string",
"minLength": 1,
"maxLength": 128
}
},
"required": [
"kind",
"id"
],
"additionalProperties": false
},
"maxItems": 32
},
"createdAt": {
"type": "string",
"format": "date-time"
},
"updatedAt": {
"type": "string",
"format": "date-time"
}
},
"required": [
"id",
"workflow",
"context",
"revision",
"activeTurnId",
"status",
"messages",
"history",
"productScope",
"references",
"createdAt",
"updatedAt"
],
"additionalProperties": false
},
"turn": {
"type": "object",
"properties": {
"sessionId": {
"type": "string",
"format": "uuid"
},
"requestId": {
"type": "string",
"format": "uuid"
},
"inputRevision": {
"type": "integer",
"exclusiveMinimum": 0
},
"revision": {
"type": "integer",
"exclusiveMinimum": 0
},
"status": {
"type": "string",
"enum": [
"running",
"completed",
"failed",
"cancelled"
]
},
"message": {
"type": "string"
},
"responseMessage": {
"type": [
"string",
"null"
]
},
"toolCalls": {
"type": "array",
"items": {
"type": "object",
"properties": {
"tool": {
"type": "string",
"pattern": "^[a-z][a-z0-9_]{0,119}$"
},
"status": {
"type": "string",
"enum": [
"completed",
"failed"
]
}
},
"required": [
"tool",
"status"
],
"additionalProperties": false
},
"maxItems": 64
},
"references": {
"type": "array",
"items": {
"type": "object",
"properties": {
"kind": {
"type": "string",
"enum": [
"persona",
"plan",
"campaign",
"creative",
"asset",
"mission",
"run"
]
},
"id": {
"type": "string",
"minLength": 1,
"maxLength": 128
}
},
"required": [
"kind",
"id"
],
"additionalProperties": false
},
"maxItems": 32
},
"createdAt": {
"type": "string",
"format": "date-time"
},
"updatedAt": {
"type": "string",
"format": "date-time"
}
},
"required": [
"sessionId",
"requestId",
"inputRevision",
"revision",
"status",
"message",
"responseMessage",
"toolCalls",
"references",
"createdAt",
"updatedAt"
],
"additionalProperties": false
},
"replay": {
"type": "boolean"
}
},
"required": [
"session",
"turn",
"replay"
],
"additionalProperties": true
}
}
}
}Operation constraints
Machine-readable metadata
{
"x-response-schema-completeness": "modeled",
"x-rate-limit": {
"requests": 300,
"windowMilliseconds": 60000,
"key": "request IP",
"headers": [
"x-ratelimit-limit",
"x-ratelimit-remaining",
"x-ratelimit-reset"
]
},
"x-idempotency": {
"policy": "not-generalized",
"note": "There is no universal Idempotency-Key middleware. Only the documented endpoint mechanisms protect retries."
}
}Complete operation
OpenAPI
{
"operationId": "post_api_v1_buyer_sessions_id_turns_requestId_complete",
"summary": "Settle the current buyer reasoning turn",
"description": "Stores bounded conversation state only if the turn revision remains active. Cancellation prevents late completion. Completion does not settle provider attempts or approve commercial actions.\n\nAuthenticated and advertiser scoped. Cross-tenant resource access returns 404. Product/channel entitlements also apply.\n\nThe request schema is generated from the runtime Zod input validator. Cross-field refinements and state-dependent constraints are additionally enforced by the API.",
"tags": [
"Buyer"
],
"security": [
{
"bearerAuth": []
}
],
"parameters": [
{
"name": "id",
"in": "path",
"required": true,
"schema": {
"type": "string",
"format": "uuid"
}
},
{
"name": "requestId",
"in": "path",
"required": true,
"schema": {
"type": "string",
"format": "uuid"
}
}
],
"requestBody": {
"required": true,
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"expectedRevision": {
"type": "integer",
"exclusiveMinimum": 0
},
"status": {
"type": "string",
"enum": [
"completed",
"failed"
]
},
"message": {
"type": "string",
"minLength": 1,
"maxLength": 16000
},
"history": {
"type": "array",
"items": {
"type": "object",
"additionalProperties": {}
},
"maxItems": 128
},
"toolCalls": {
"type": "array",
"items": {
"type": "object",
"properties": {
"tool": {
"type": "string",
"pattern": "^[a-z][a-z0-9_]{0,119}$"
},
"status": {
"type": "string",
"enum": [
"completed",
"failed"
]
}
},
"required": [
"tool",
"status"
],
"additionalProperties": false
},
"maxItems": 64,
"default": []
},
"references": {
"type": "array",
"items": {
"type": "object",
"properties": {
"kind": {
"type": "string",
"enum": [
"persona",
"plan",
"campaign",
"creative",
"asset",
"mission",
"run"
]
},
"id": {
"type": "string",
"minLength": 1,
"maxLength": 128
}
},
"required": [
"kind",
"id"
],
"additionalProperties": false
},
"maxItems": 32,
"default": []
}
},
"required": [
"expectedRevision",
"status",
"message"
],
"additionalProperties": false
}
}
}
},
"responses": {
"400": {
"description": "Invalid request or unsupported fields",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"401": {
"description": "Missing or invalid authentication",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"403": {
"description": "Permission or product scope refused",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"404": {
"description": "Route or tenant-scoped resource not found",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"409": {
"description": "State, revision, approval, funding or idempotency conflict",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"422": {
"description": "Supplier configuration, capability or upstream refusal",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"429": {
"description": "Rate limit reached; wait before retrying",
"headers": {
"x-ratelimit-limit": {
"description": "Maximum requests permitted in the current rate-limit window.",
"schema": {
"type": "integer"
}
},
"x-ratelimit-remaining": {
"description": "Requests remaining in the current window.",
"schema": {
"type": "integer"
}
},
"x-ratelimit-reset": {
"description": "Seconds until the current rate-limit window resets.",
"schema": {
"type": "integer"
}
},
"retry-after": {
"description": "Minimum seconds to wait before retrying.",
"schema": {
"type": "integer"
}
}
},
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"500": {
"description": "Internal error; inspect state before retrying a mutation",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"503": {
"description": "Dependency or authentication verifier unavailable",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
},
"2XX": {
"description": "Successful response.",
"headers": {
"x-ratelimit-limit": {
"description": "Maximum requests permitted in the current rate-limit window.",
"schema": {
"type": "integer"
}
},
"x-ratelimit-remaining": {
"description": "Requests remaining in the current window.",
"schema": {
"type": "integer"
}
},
"x-ratelimit-reset": {
"description": "Seconds until the current rate-limit window resets.",
"schema": {
"type": "integer"
}
}
},
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"session": {
"type": "object",
"properties": {
"id": {
"type": "string",
"format": "uuid"
},
"workflow": {
"type": "string",
"enum": [
"brief_to_plan",
"creative_direction",
"campaign_review",
"launch_assistance"
]
},
"context": {
"type": "object",
"properties": {
"campaignId": {
"type": "string",
"minLength": 1,
"maxLength": 128
},
"planId": {
"type": "string",
"minLength": 1,
"maxLength": 128
},
"personaId": {
"type": "string",
"minLength": 1,
"maxLength": 128
},
"creativeId": {
"type": "string",
"minLength": 1,
"maxLength": 128
}
},
"additionalProperties": false
},
"revision": {
"type": "integer",
"exclusiveMinimum": 0
},
"activeTurnId": {
"anyOf": [
{
"type": "string",
"format": "uuid"
},
{
"type": "null"
}
]
},
"status": {
"type": "string",
"enum": [
"running",
"idle"
]
},
"messages": {
"type": "array",
"items": {
"type": "object",
"properties": {
"role": {
"type": "string",
"enum": [
"user",
"assistant"
]
},
"message": {
"type": "string"
},
"requestId": {
"type": "string",
"format": "uuid"
}
},
"required": [
"role",
"message",
"requestId"
],
"additionalProperties": false
},
"maxItems": 40
},
"history": {
"type": "array",
"items": {
"type": "object",
"additionalProperties": {}
},
"maxItems": 128
},
"productScope": {
"type": "object",
"properties": {
"product": {
"type": "string",
"enum": [
"adbuymcp",
"doohmcp",
"ctvmcp"
]
},
"channels": {
"type": "array",
"items": {
"type": "string",
"enum": [
"ctv",
"audio",
"tv",
"cinema",
"dooh",
"search",
"social"
]
},
"minItems": 1,
"maxItems": 7
}
},
"required": [
"product",
"channels"
],
"additionalProperties": false
},
"references": {
"type": "array",
"items": {
"type": "object",
"properties": {
"kind": {
"type": "string",
"enum": [
"persona",
"plan",
"campaign",
"creative",
"asset",
"mission",
"run"
]
},
"id": {
"type": "string",
"minLength": 1,
"maxLength": 128
}
},
"required": [
"kind",
"id"
],
"additionalProperties": false
},
"maxItems": 32
},
"createdAt": {
"type": "string",
"format": "date-time"
},
"updatedAt": {
"type": "string",
"format": "date-time"
}
},
"required": [
"id",
"workflow",
"context",
"revision",
"activeTurnId",
"status",
"messages",
"history",
"productScope",
"references",
"createdAt",
"updatedAt"
],
"additionalProperties": false
},
"turn": {
"type": "object",
"properties": {
"sessionId": {
"type": "string",
"format": "uuid"
},
"requestId": {
"type": "string",
"format": "uuid"
},
"inputRevision": {
"type": "integer",
"exclusiveMinimum": 0
},
"revision": {
"type": "integer",
"exclusiveMinimum": 0
},
"status": {
"type": "string",
"enum": [
"running",
"completed",
"failed",
"cancelled"
]
},
"message": {
"type": "string"
},
"responseMessage": {
"type": [
"string",
"null"
]
},
"toolCalls": {
"type": "array",
"items": {
"type": "object",
"properties": {
"tool": {
"type": "string",
"pattern": "^[a-z][a-z0-9_]{0,119}$"
},
"status": {
"type": "string",
"enum": [
"completed",
"failed"
]
}
},
"required": [
"tool",
"status"
],
"additionalProperties": false
},
"maxItems": 64
},
"references": {
"type": "array",
"items": {
"type": "object",
"properties": {
"kind": {
"type": "string",
"enum": [
"persona",
"plan",
"campaign",
"creative",
"asset",
"mission",
"run"
]
},
"id": {
"type": "string",
"minLength": 1,
"maxLength": 128
}
},
"required": [
"kind",
"id"
],
"additionalProperties": false
},
"maxItems": 32
},
"createdAt": {
"type": "string",
"format": "date-time"
},
"updatedAt": {
"type": "string",
"format": "date-time"
}
},
"required": [
"sessionId",
"requestId",
"inputRevision",
"revision",
"status",
"message",
"responseMessage",
"toolCalls",
"references",
"createdAt",
"updatedAt"
],
"additionalProperties": false
},
"replay": {
"type": "boolean"
}
},
"required": [
"session",
"turn",
"replay"
],
"additionalProperties": true
}
}
}
}
},
"x-response-schema-completeness": "modeled",
"x-rate-limit": {
"requests": 300,
"windowMilliseconds": 60000,
"key": "request IP",
"headers": [
"x-ratelimit-limit",
"x-ratelimit-remaining",
"x-ratelimit-reset"
]
},
"x-idempotency": {
"policy": "not-generalized",
"note": "There is no universal Idempotency-Key middleware. Only the documented endpoint mechanisms protect retries."
}
}