> ## Documentation Index > Fetch the complete documentation index at: https://v2.docs.conduit.financial/llms.txt > Use this file to discover all available pages before exploring further. # Add a signer to a customer's wallets > Adds a new signer to the customer's wallet infrastructure. The synchronous response returns a `verificationUrl` whose audience is given by `urlAudience`: a passkey signer gets their own enrollment link (`urlAudience: "signer"`, also delivered via the `wallet_signer.invited` webhook) — deliver it to the signer; an api_key signer that parks for admin approval gets a customer admin's co-stamp link (`urlAudience: "admin"`, also delivered via the `wallet_ceremony.awaiting_admin_approval` webhook) — deliver it to an admin; a synchronously-admitted api_key signer returns null/null. Conduit never emails anyone — your platform delivers the link. Route by `urlAudience`, never assume the URL is the signer's. ## OpenAPI ````yaml https://api.sandbox.conduit.financial/v2/api-docs/openapi.json post /customers/{customerId}/wallet-signers openapi: 3.0.0 info: title: Conduit Sandbox API description: >- **Sandbox API** — clients integrate against this surface to exercise happy and unhappy paths without consuming real KYC/PSP credits or moving real money. Customer KYC, banking partners, and crypto custody are stubbed; org-level KYB runs against real providers. Simulation endpoints under `/v2/sandbox/*` drive specific scenarios. Internal and portal endpoints are excluded from this spec. version: '2.0' contact: {} servers: - url: https://api.sandbox.conduit.financial/v2 description: Sandbox - url: https://api.conduit.financial/v2 description: Production security: - api-key: [] tags: - name: Customers - name: Registered Addresses - name: Wallets - name: Wallet Signers - name: Signing Quorum - name: Virtual Accounts - name: Applications - name: Documents - name: Verifications - name: Signing Requests - name: Transactions - name: Payouts - name: Whitelist Recipients - name: Orders - name: RFIs - name: Webhook Endpoints - name: Webhook Deliveries - name: Webhook Event Types - name: Features - name: Customer Onboarding - name: Sandbox paths: /customers/{customerId}/wallet-signers: post: tags: - Wallet Signers summary: Add a signer to a customer's wallets description: >- Adds a new signer to the customer's wallet infrastructure. The synchronous response returns a `verificationUrl` whose audience is given by `urlAudience`: a passkey signer gets their own enrollment link (`urlAudience: "signer"`, also delivered via the `wallet_signer.invited` webhook) — deliver it to the signer; an api_key signer that parks for admin approval gets a customer admin's co-stamp link (`urlAudience: "admin"`, also delivered via the `wallet_ceremony.awaiting_admin_approval` webhook) — deliver it to an admin; a synchronously-admitted api_key signer returns null/null. Conduit never emails anyone — your platform delivers the link. Route by `urlAudience`, never assume the URL is the signer's. operationId: WalletSignersController_addSigner_v2 parameters: - name: customerId required: true in: path schema: type: string - name: Idempotency-Key in: header description: >- Caller-generated unique key that lets the server safely replay this request. The cached response is returned for 5 minutes on any retry with the same key from the same API principal. Required on every state-changing money-moving or resource-creating POST. required: true schema: type: string pattern: ^[A-Za-z0-9_.:-]{1,128}$ minLength: 1 maxLength: 128 requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/AddWalletSignerDto' responses: '201': description: '' content: application/json: schema: $ref: '#/components/schemas/AddWalletSignerResponseDto' '400': description: >- **INVALID_OID_FORMAT**: A path or query parameter expected a valid object identifier but received a value that does not match the expected format. **VALIDATION_ERROR**: The request body or query parameters failed validation. One or more fields have invalid values, missing required properties, or incorrect types. Multipart file uploads that fail at the multipart-parser layer (unexpected form-field name, too many parts) carry an extra 'field' member naming the offending form-field. **MALFORMED_JSON**: The request body could not be parsed as JSON. Bodies declared as 'application/json' — and bodies with no Content-Type header, which are assumed to be JSON — must contain syntactically valid JSON. **IDEMPOTENCY_KEY_REQUIRED**: This endpoint requires an Idempotency-Key header to prevent duplicate processing. Generate a unique key per logical request and resend the request. **IDEMPOTENCY_KEY_INVALID**: The Idempotency-Key header value did not match the required shape (1-128 characters, letters / digits / underscore / dot / colon / hyphen). **IDEMPOTENCY_BODY_TOO_NESTED**: The request body exceeds the maximum nesting depth allowed by the idempotency fingerprint hasher. Deeply-nested arrays or objects are rejected as a malformed payload. **API_KEY_PUBLIC_KEY_REQUIRED**: credentialType=api_key requires a publicKey (a P-256 compressed public key in hex). **API_KEY_PUBLIC_KEY_INVALID**: The provided `publicKey` is not a valid P-256 compressed public key. Expected 66 hex characters (33 bytes) with a `02` or `03` prefix. content: application/json: schema: $ref: '#/components/schemas/ValidationErrorDto' example: type: INVALID_OID_FORMAT title: Invalid Object ID Format status: 400 detail: >- A path or query parameter expected a valid object identifier but received a value that does not match the expected format. resolution: >- Verify that all IDs in the request URL and query parameters are correctly formatted. IDs are typically prefixed strings like 'cus_...', 'app_...', or 'doc_...'. docs: https://conduit-v2.mintlify.app/errors#invalid-oid-format instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' '401': description: >- **API_KEY_MISSING**: The request did not include an API key. All API requests must be authenticated. **API_KEY_INVALID**: The provided API key is not recognized or has been revoked. content: application/json: schema: $ref: '#/components/schemas/ProblemDetailDto' example: type: API_KEY_MISSING title: API Key Missing status: 401 detail: >- The request did not include an API key. All API requests must be authenticated. resolution: >- Include your API key in the 'x-api-key' header with every request. docs: https://conduit-v2.mintlify.app/errors#api-key-missing instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' '403': description: >- **API_KEY_READ_ONLY**: This API key has read-only access and cannot perform write operations. Read-only keys may make read requests (GET, HEAD, OPTIONS) only. **FEATURE_NOT_ENABLED**: Your account does not have access to this feature. Features are enabled on a per-account basis. content: application/json: schema: $ref: '#/components/schemas/ProblemDetailDto' example: type: API_KEY_READ_ONLY title: API Key Is Read-Only status: 403 detail: >- This API key has read-only access and cannot perform write operations. Read-only keys may make read requests (GET, HEAD, OPTIONS) only. resolution: >- Use a read-write API key for this request, or have an organization admin mint one from the dashboard. docs: https://conduit-v2.mintlify.app/errors#api-key-read-only instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' '404': description: >- **CUSTOMER_NOT_FOUND**: No customer exists with the specified ID, or the customer belongs to a different organization. content: application/json: schema: $ref: '#/components/schemas/ProblemDetailDto' example: type: CUSTOMER_NOT_FOUND title: Customer Not Found status: 404 detail: >- No customer exists with the specified ID, or the customer belongs to a different organization. resolution: >- Verify the customer ID is correct. Use the list customers endpoint to find valid customer IDs for your organization. docs: https://conduit-v2.mintlify.app/errors#customer-not-found instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' '409': description: >- **IDEMPOTENCY_KEY_CONFLICT**: The idempotency key was previously used with a different request body. Idempotency keys are bound to the exact request shape — replays must match the original. **IDEMPOTENCY_KEY_REQUEST_IN_PROGRESS**: A request with this idempotency key is already being processed and has not yet completed. Concurrent requests with the same key are rejected to prevent duplicate execution. **API_KEY_PUBLIC_KEY_IN_USE**: The `publicKey` on this add-signer request is already held by another active api_key signer on the customer's roster. Each machine signer must have a distinct P-256 public key. content: application/json: schema: $ref: '#/components/schemas/ProblemDetailDto' example: type: IDEMPOTENCY_KEY_CONFLICT title: Idempotency Key Conflict status: 409 detail: >- The idempotency key was previously used with a different request body. Idempotency keys are bound to the exact request shape — replays must match the original. resolution: >- Use a fresh idempotency key for the new request, or replay the original request unchanged. docs: >- https://conduit-v2.mintlify.app/errors#idempotency-key-conflict instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' '415': description: >- **UNSUPPORTED_MEDIA_TYPE**: The request carries a body with a Content-Type this endpoint cannot parse. JSON endpoints accept 'application/json'; a body with no Content-Type header at all is assumed to be JSON. File-upload endpoints accept only 'multipart/form-data' — JSON or undeclared bodies are rejected there. content: application/json: schema: $ref: '#/components/schemas/ProblemDetailDto' example: type: UNSUPPORTED_MEDIA_TYPE title: Unsupported Media Type status: 415 detail: >- The request carries a body with a Content-Type this endpoint cannot parse. JSON endpoints accept 'application/json'; a body with no Content-Type header at all is assumed to be JSON. File-upload endpoints accept only 'multipart/form-data' — JSON or undeclared bodies are rejected there. resolution: >- Send the request body with the 'Content-Type: application/json' header. For file uploads, use 'Content-Type: multipart/form-data' — upload endpoints accept no other body type. docs: https://conduit-v2.mintlify.app/errors#unsupported-media-type instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' '422': description: >- **SIGNERS_NOT_SUPPORTED**: Signers can only be managed on non-custodial wallets. This customer's wallet is custodial, so the backend signs on its behalf. **UNPROCESSABLE_ENTITY**: The request was well-formed but could not be processed due to semantic errors or business rule violations. **API_KEY_CREDENTIAL_NOT_SUPPORTED**: The request includes a machine signer (`credentialType: api_key`) in a context where api_key signers cannot be enrolled. This is reserved for future compatibility and should not be seen in normal operation. **WALLET_NO_PROVIDER_ACCOUNT**: The customer does not yet have a wallet account on the underlying provider. Wallet addresses cannot be created until the customer claims non-custodial control. content: application/json: schema: $ref: '#/components/schemas/ProblemDetailDto' example: type: SIGNERS_NOT_SUPPORTED title: Signers Not Supported status: 422 detail: >- Signers can only be managed on non-custodial wallets. This customer's wallet is custodial, so the backend signs on its behalf. resolution: >- Claim the wallet as non-custodial via POST /v2/customers/:id/wallets/claim-non-custodial before adding or removing signers. docs: https://conduit-v2.mintlify.app/errors#signers-not-supported instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' '429': description: >- **RATE_LIMITED**: Too many requests. This error is returned by three independent checks: the per-organization bucket applied to every authenticated API request; the per-IP bucket applied to unauthenticated traffic before an API key is validated; and the per-IP bucket applied when repeated invalid API keys are submitted from the same address. Honor the Retry-After header (also exposed as retryAfterSeconds in the body) before retrying. Current limits and remaining budget are visible in X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset on rate-limited route responses. content: application/json: schema: $ref: '#/components/schemas/RateLimitedErrorDto' example: type: RATE_LIMITED title: Rate Limited status: 429 detail: >- Too many requests. This error is returned by three independent checks: the per-organization bucket applied to every authenticated API request; the per-IP bucket applied to unauthenticated traffic before an API key is validated; and the per-IP bucket applied when repeated invalid API keys are submitted from the same address. Honor the Retry-After header (also exposed as retryAfterSeconds in the body) before retrying. Current limits and remaining budget are visible in X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset on rate-limited route responses. resolution: >- Sleep until Retry-After seconds have elapsed, then retry. For sustained workloads exceeding the per-organization defaults, request a rate-limit increase through your support contact. docs: https://conduit-v2.mintlify.app/errors#rate-limited instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' retryAfterSeconds: 3 '500': description: >- **INTERNAL_ERROR**: An unexpected error occurred while processing your request. content: application/json: schema: $ref: '#/components/schemas/ProblemDetailDto' example: type: INTERNAL_ERROR title: Internal Error status: 500 detail: An unexpected error occurred while processing your request. resolution: >- Retry the request after a brief delay. If the error persists, contact support and include the correlationId from the error response for investigation. docs: https://conduit-v2.mintlify.app/errors#internal-error instance: /v2/... correlationId: req_a1b2c3d4 timestamp: '2026-01-15T09:30:00.000Z' components: schemas: AddWalletSignerDto: type: object properties: email: type: string format: email pattern: >- ^(?!\.)(?!.*\.\.)([A-Za-z0-9_'+\-\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$ description: Email address of the signer to add example: signer@example.com name: description: Display name of the signer example: Jane Doe type: string role: description: >- admin = root-quorum member + signing-quorum member; signer = signing-quorum only type: string enum: - admin - signer credentialType: description: How this signer will stamp. api_key requires `publicKey`. type: string enum: - passkey - api_key publicKey: description: >- Machine-signer P-256 compressed public key (33 bytes, 02/03 prefix + 64 hex chars, optional 0x prefix). Required when credentialType=api_key. example: 02a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2 type: string required: - email additionalProperties: false AddWalletSignerResponseDto: type: object properties: id: type: string pattern: ^wsg_[0-9A-Za-z]{22}$ description: Unique wallet signer identifier email: type: string description: Signer's email address example: signer@example.com name: type: string description: Signer's display name example: Jane Doe nullable: true role: description: >- admin = root-quorum member + signing-quorum member; signer = signing-quorum only type: string enum: - admin - signer credentialType: description: How this signer stamps requests type: string enum: - passkey - api_key passkeyCount: type: integer minimum: 0 maximum: 9007199254740991 description: Number of passkeys enrolled for this signer example: 0 status: description: Current signer status type: string enum: - pending_activation - activating - active - pending_removal - removed - error createdAt: type: string format: date-time description: Timestamp when the signer was created example: '2026-01-15T09:30:00.000Z' updatedAt: type: string format: date-time description: Timestamp when the signer was last updated example: '2026-01-15T09:30:00.000Z' verificationUrl: type: string description: >- Synchronous URL for this add, or null when none applies. Read `urlAudience` to know who it is for before delivering it — a passkey add returns the signer's enrollment link, an api_key add pending approval returns a customer admin's co-stamp link. example: https://app.conduit.financial/verify/vtok_2xKjF9mQb7vN4hL1pR3w8t nullable: true urlAudience: type: string enum: - signer - admin description: >- Audience of `verificationUrl`: `signer` = the new signer's credential-enrollment link (deliver to the signer); `admin` = a customer admin's approval link (deliver to an admin; also delivered via the `wallet_ceremony.awaiting_admin_approval` webhook); null when there is no URL. nullable: true required: - id - email - name - role - credentialType - passkeyCount - status - createdAt - updatedAt - verificationUrl - urlAudience ValidationErrorDto: type: object properties: type: type: string description: Machine-readable error code example: CUSTOMER_NOT_FOUND title: type: string description: Human-readable error type label example: Customer Not Found status: type: number description: HTTP status code example: 404 detail: type: string description: Human-readable explanation of this occurrence example: Customer with id cus_abc123 not found resolution: type: string description: What the developer should do to resolve this error example: >- Verify the customer ID. Check you are using the correct API key for this organization. docs: type: string description: URL to error documentation example: https://conduit-v2.mintlify.app/errors#customer-not-found instance: type: string description: Request path that produced the error example: /v2/customers/cus_abc123 correlationId: description: Request correlation ID example: req_a1b2c3d4 type: string timestamp: type: string description: ISO 8601 UTC timestamp example: '2026-04-27T20:00:00.000Z' details: description: >- Additional structured data for domain-specific errors (e.g. missing field lists, pair info) errors: type: array items: type: object properties: pointer: type: string description: JSON pointer to the invalid field example: /email detail: type: string description: What is wrong with this field example: Invalid email format allowedValues: description: The values this field accepts, when it is a closed set example: - ach - fedwire - rtp type: array items: type: string category: description: >- Class of blocker (requirements-validator output only). 'field' = form-field gap, 'document' = missing or insufficient document (including per-UBO document slots), 'individual' = required person missing. example: field type: string enum: - field - document - individual required: - pointer - detail required: - type - title - status - detail - resolution - docs - instance - timestamp ProblemDetailDto: type: object properties: type: type: string description: Machine-readable error code example: CUSTOMER_NOT_FOUND title: type: string description: Human-readable error type label example: Customer Not Found status: type: number description: HTTP status code example: 404 detail: type: string description: Human-readable explanation of this occurrence example: Customer with id cus_abc123 not found resolution: type: string description: What the developer should do to resolve this error example: >- Verify the customer ID. Check you are using the correct API key for this organization. docs: type: string description: URL to error documentation example: https://conduit-v2.mintlify.app/errors#customer-not-found instance: type: string description: Request path that produced the error example: /v2/customers/cus_abc123 correlationId: description: Request correlation ID example: req_a1b2c3d4 type: string timestamp: type: string description: ISO 8601 UTC timestamp example: '2026-04-27T20:00:00.000Z' details: description: >- Additional structured data for domain-specific errors (e.g. missing field lists, pair info) required: - type - title - status - detail - resolution - docs - instance - timestamp RateLimitedErrorDto: type: object properties: type: type: string description: Machine-readable error code example: CUSTOMER_NOT_FOUND title: type: string description: Human-readable error type label example: Customer Not Found status: type: number description: HTTP status code example: 404 detail: type: string description: Human-readable explanation of this occurrence example: Customer with id cus_abc123 not found resolution: type: string description: What the developer should do to resolve this error example: >- Verify the customer ID. Check you are using the correct API key for this organization. docs: type: string description: URL to error documentation example: https://conduit-v2.mintlify.app/errors#customer-not-found instance: type: string description: Request path that produced the error example: /v2/customers/cus_abc123 correlationId: description: Request correlation ID example: req_a1b2c3d4 type: string timestamp: type: string description: ISO 8601 UTC timestamp example: '2026-04-27T20:00:00.000Z' details: description: >- Additional structured data for domain-specific errors (e.g. missing field lists, pair info) retryAfterSeconds: type: integer minimum: 0 exclusiveMinimum: true maximum: 9007199254740991 description: Seconds to wait before retrying example: 3 required: - type - title - status - detail - resolution - docs - instance - timestamp - retryAfterSeconds securitySchemes: api-key: type: apiKey in: header name: x-api-key ````