> ## Documentation Index > Fetch the complete documentation index at: https://docs.userkit.dev/llms.txt > Use this file to discover all available pages before exploring further. # Change a member's role > Owner only. You cannot change your own role — that is how a person hands themselves everything — and the last owner cannot be demoted. ## OpenAPI ````yaml /api-reference/openapi.json put /v1/contact/customer/members/{contactId}/role openapi: 3.1.0 info: title: UserKit API version: 1.0.0 description: >- The HTTP surface of UserKit. Two planes share one API. The **staff plane** is what a human uses in the panel: users, organizations, roles, members, keys. The **customer plane** is what a developer's own product uses: contacts, identities, hosted or federated sign-in. Every error answers the same envelope — `{"error": {"code", "message"}}`. The `code` is a stable contract to branch on; the `message` is for a person and may change. servers: - url: '{baseUrl}' description: The API host. variables: baseUrl: default: https://api.userkit.dev description: Base URL of the API, no trailing slash. security: - sessionToken: [] tags: - name: Authentication description: >- Public sign-up, sign-in, two-factor and password recovery for staff accounts. - name: Session description: >- The active session: who the caller is, which organization they are in, and signing out. - name: Account description: The caller's own account — profile, password, sessions, avatar. - name: Two-factor description: >- TOTP setup, activation and recovery codes. Returns 501 when two-factor is unavailable on the server. - name: Organizations description: The organizations a user belongs to, and the active one. - name: Environments description: >- The live and test environments seeded with every organization, and their identity settings. - name: Members description: Memberships and invitations. - name: Roles description: Roles and the permission catalogue they draw from. - name: Audit log description: >- What staff did inside an organization. Append-only, and read behind its own permission. - name: API keys description: Secret keys (`uk_sk_…`) and publishable keys (`uk_pk_…`). - name: Contacts (staff session) description: >- The staff view of the customer plane, opened by a staff session. Reads take `?environment=` as an explicit view parameter. - name: Contacts (API key) description: >- The machine surface, authenticated by an API key. The environment is the key's environment and cannot be named by the caller. - name: Customer plane description: >- Called from the developer's own pages with a publishable key: boot, magic link, and the contact's own session. - name: Hosted auth description: >- Sign-up, sign-in, verification and recovery for contacts, when UserKit owns the account. - name: Customer teams description: >- A customer is a team. Its roster, its invitations and its two roles — owner and member — administered by the contact's own session. The active customer travels in `X-Customer-Id`. - name: Webhooks description: >- Outbound webhooks: endpoints, the published event catalogue, the delivery log, replay and test sends. Never gated by a plan — webhooks are a developer primitive. - name: Catalogue description: >- The plans, prices and features **you** sell to your own customers. Per environment, a price per currency, and `recurring` or `one_time`. Distinct from the plan you are on with UserKit, which is `GET /v1/organization/entitlements`. - name: Subscriptions description: >- What one of **your** customers is paying you, mirrored from the gateway that charges them. The gateway is the truth about money — it holds the schedule, runs the retries and decides what a proration is worth — so these routes ask it to change something and answer with what it then said. `provider_synced_at` is how stale the copy admits to being. - name: Provider webhooks description: >- Where a payment provider delivers to. Not a surface you call — it is a URL you paste into the provider's dashboard, which is why it sits outside `/v1`: a version bump must never mean editing a setting in somebody else's product. Signed with the secret of the connection named in the path, and safe to retry. - name: Entitlements description: >- What one of **your** customers may do, resolved: the plan their subscription carries, plus the overrides you promised them on top. This is the read your own gate calls, so it is cached and answers in one round trip. It is a different question from `GET /v1/organization/entitlements`, which is the plan **you** are on with UserKit — two catalogues, same word, different money. paths: /v1/contact/customer/members/{contactId}/role: put: tags: - Customer teams summary: Change a member's role description: >- Owner only. You cannot change your own role — that is how a person hands themselves everything — and the last owner cannot be demoted. operationId: assignCustomerMemberRole parameters: - $ref: '#/components/parameters/CustomerHeader' - name: contactId in: path required: true schema: type: string format: uuid requestBody: required: true content: application/json: schema: type: object required: - role properties: role: type: string enum: - owner - member responses: '204': description: Changed. '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/CustomerOwnerOnly' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/LastCustomerOwner' '429': $ref: '#/components/responses/RateLimited' security: - contactToken: [] components: parameters: CustomerHeader: name: X-Customer-Id in: header required: false schema: type: string format: uuid description: >- The customer this call is acting inside — the same arrangement as `X-Organization-Id`, one plane down. Switching customers is **navigation, not a mutation**: nothing is stored, you send a different header, and the membership JOIN behind it decides what you may do there. An id you are not a member of matches no row and answers `404`. Absent, the contact's oldest membership answers. responses: BadRequest: description: '`invalid_request` — the body or a parameter is malformed.' content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: >- `unauthorized` — missing, malformed or expired credential. A well-formed credential from the wrong family says so: "this endpoint expects a staff session token, not an organization API key". content: application/json: schema: $ref: '#/components/schemas/Error' CustomerOwnerOnly: description: >- `forbidden` — only an owner of this customer can do this. There is no permission catalogue down here: administering the team is what owner *means*, and everything else a member may already do. Also `unverified_session`. content: application/json: schema: $ref: '#/components/schemas/Error' NotFound: description: >- `not_found`. Also the answer for a resource that exists in another organization or environment — the 404 never reveals which. content: application/json: schema: $ref: '#/components/schemas/Error' LastCustomerOwner: description: >- `last_owner` — this customer must keep at least one owner. The same invariant as the organization's, one plane down: promote somebody else first, then leave or be demoted. content: application/json: schema: $ref: '#/components/schemas/Error' RateLimited: description: >- `rate_limited` — too many requests. `Retry-After` carries the window in seconds. The counters are shared across instances. When that store cannot be reached each instance counts on its own instead: the limits get looser, never absent. headers: Retry-After: schema: type: integer description: Seconds until the window resets. content: application/json: schema: $ref: '#/components/schemas/Error' schemas: Error: type: object description: Every error in this API answers this envelope. properties: error: type: object properties: code: type: string description: Stable. Branch on this. message: type: string description: For a person. May change. required: - code - message required: - error example: error: code: forbidden message: your role does not allow this action securitySchemes: sessionToken: type: http scheme: bearer description: >- A staff session token, `uk_st_…`. Minted by sign-up, sign-in or the two-factor exchange. contactToken: type: http scheme: bearer description: >- A contact session token, `uk_ct_…`. Belongs to one of the developer's own users, and reads only that user's data. ````