> ## Documentation Index > Fetch the complete documentation index at: https://docs.staging.cope-demo.com/llms.txt > Use this file to discover all available pages before exploring further. # Move a subscription to another plan ## OpenAPI ````yaml /api-reference/commerce-v1.openapi.json post /v1/commerce/subscriptions/{id}/plan openapi: 3.0.3 info: description: >- Public REST API for COPE vendor integrations. Authenticate with a COPE API key or Clerk bearer token and call the endpoints described below. title: COPE Public API version: v1 servers: - description: Production url: https://api.cope.com security: - cope_sk: [] paths: /v1/commerce/subscriptions/{id}/plan: post: tags: - Subscriptions summary: Move a subscription to another plan operationId: commerce.subscriptions.plan_changes.create parameters: - description: id public identifier. example: sub_A1b2C3d4E5f6G7h8 in: path name: id required: true schema: example: sub_A1b2C3d4E5f6G7h8 pattern: ^sub_[A-Za-z0-9]{8,32}$ type: string - description: >- Required. At most 255 characters of valid UTF-8 with no NUL byte. The change attempt is recorded against this key for this subscription: a retry that carries the same key and the same body returns the original response instead of changing the subscription twice, and the same key with a different body is refused with 409 idempotency_conflict. in: header name: Idempotency-Key required: true schema: maxLength: 255 type: string requestBody: content: application/json: schema: additionalProperties: false properties: plan_id: example: plan_A1b2C3d4 pattern: ^plan_[A-Za-z0-9]{8,32}$ type: string required: - plan_id type: object responses: '200': content: application/json: schema: additionalProperties: false properties: data: additionalProperties: false properties: effective_at: type: string effective_confirmed_at: nullable: true type: string failure: additionalProperties: false nullable: true properties: code: type: string message: type: string required: - code - message type: object from: additionalProperties: false properties: amount_cents: type: integer currency: type: string plan_id: nullable: true type: string required: - plan_id - amount_cents - currency type: object reason: nullable: true type: string requested_by: additionalProperties: false properties: actor_id: type: string actor_type: type: string business_id: type: string initiated_by: type: string required: - initiated_by - actor_type - actor_id - business_id type: object status: type: string subscription_id: type: string to: additionalProperties: false properties: amount_cents: type: integer currency: type: string plan_id: type: string required: - plan_id - amount_cents - currency type: object type: type: string required: - subscription_id - type - status - effective_at - effective_confirmed_at - reason - from - to - requested_by - failure type: object required: - data type: object description: Successful response '400': content: application/problem+json: examples: subscription_idempotency_key_required: summary: Missing Idempotency-Key header value: code: idempotency_key_required detail: >- an Idempotency-Key header is required for a subscription change errors: - code: idempotency_key_required detail: >- an Idempotency-Key header is required for a subscription change param: idempotency_key request_id: req_123 status: 400 title: Idempotency Key Required type: https://docs.cope.com/errors/idempotency_key_required subscription_invalid_idempotency_key: summary: Malformed Idempotency-Key header value: code: invalid_idempotency_key detail: >- Idempotency-Key header must be at most 255 characters of valid UTF-8 without a NUL byte errors: - code: invalid_idempotency_key detail: >- Idempotency-Key header must be at most 255 characters of valid UTF-8 without a NUL byte param: idempotency_key request_id: req_123 status: 400 title: Invalid Idempotency Key type: https://docs.cope.com/errors/invalid_idempotency_key unparsable_request: summary: Unparsable request value: code: invalid_request detail: >- The request could not be parsed. Check the query string and the request body. request_id: req_123 status: 400 title: Invalid Request type: https://docs.cope.com/errors/invalid_request schema: $ref: '#/components/schemas/PublicProblemDetail' description: Invalid request '401': content: application/problem+json: schema: $ref: '#/components/schemas/PublicProblemDetail' description: Missing or invalid bearer token '403': content: application/problem+json: schema: $ref: '#/components/schemas/PublicProblemDetail' description: Bearer token is not authorized for this route '404': content: application/problem+json: schema: $ref: '#/components/schemas/PublicProblemDetail' description: Resource not found '409': content: application/problem+json: examples: subscription_idempotency_conflict: summary: Idempotency key reused with a different body value: code: idempotency_conflict detail: >- request body does not match the original request for this idempotency key errors: - code: idempotency_body_mismatch detail: >- request body does not match the original request for this idempotency key param: idempotency_key request_id: req_123 status: 409 title: Idempotency Conflict type: https://docs.cope.com/errors/idempotency_conflict schema: $ref: '#/components/schemas/PublicProblemDetail' description: >- The idempotency key was already used for this subscription with a different body. '422': content: application/problem+json: examples: subscription_validation_failed: summary: The body carries an invalid or unsupported member value: code: validation_failed detail: null errors: - code: unsupported detail: amount_cent is not supported by this public endpoint param: amount_cent request_id: req_123 status: 422 title: Validation Failed type: https://docs.cope.com/errors/validation_failed plan_not_available: summary: The target plan cannot be moved to value: code: plan_not_available detail: target plan is not on this product for this business errors: - code: plan_not_available detail: target plan is not on this product for this business param: plan_id request_id: req_123 status: 422 title: Plan Not Available type: https://docs.cope.com/errors/plan_not_available too_close_to_renewal: summary: The next renewal is inside the change cutoff value: code: too_close_to_renewal detail: too close to renewal errors: - code: too_close_to_renewal detail: too close to renewal param: subscription_id request_id: req_123 status: 422 title: Too Close To Renewal type: https://docs.cope.com/errors/too_close_to_renewal subscription_not_eligible: summary: The subscription cannot be changed value: code: subscription_not_eligible detail: installment plan errors: - code: installment_plan detail: installment plan param: subscription_id request_id: req_123 status: 422 title: Subscription Not Eligible type: https://docs.cope.com/errors/subscription_not_eligible schema: $ref: '#/components/schemas/PublicProblemDetail' description: The body is invalid, or the subscription cannot be changed now security: - cope_sk: [] components: schemas: PublicProblemDetail: additionalProperties: false properties: code: type: string detail: nullable: true type: string errors: items: additionalProperties: false properties: code: type: string detail: type: string param: type: string required: - code - detail type: object type: array request_id: type: string status: type: integer title: type: string type: type: string required: - type - title - status - code - request_id type: object securitySchemes: cope_sk: description: >- Bearer credential for the public API. Vendor integrations should send a live COPE API key (`ck_live_*`; keys issued earlier as `cope_sk_live_*` keep working). Clerk bearer tokens are also accepted when paired with `X-Cope-Business-Id`. scheme: bearer type: http ````