> ## Documentation Index > Fetch the complete documentation index at: https://docs.dakota.xyz/llms.txt > Use this file to discover all available pages before exploring further. # Add a signer to a signer group > Adds an existing signer to a signer group. ## OpenAPI ````yaml /openapi.yaml post /signer-groups/{signer_group_id}/signers openapi: 3.0.3 info: title: Dakota Platform API version: 1.0.0 description: >- Combined API specification for Dakota Platform services: - Issuance API: Asset minting and burning operations - Onboarding API: Know Your Business/Customer verification - On/Off Ramp API: Managing on-ramp and off-ramp accounts - Recipients API: Managing destinations for KYB'd entities - Transactions API: Viewing transaction history across platform operations ## Authentication and API Headers All API endpoints require the following headers: - `x-idempotency-key`: Required for all POST endpoints to ensure request idempotency - `x-api-key`: Required for authentication across all endpoints Note: On /applications endpoints you need a token for authentication instead of a x-api-key - `x-application-token`: Required for authentication on public /applications endpoints (alternative to `x-api-key` where documented) ## Rate Limits Requests are rate limited per API key. Every response includes the following headers: | Header | Description | | --- | --- | | `X-RateLimit-Limit` | Maximum requests allowed in the current one-minute window. | | `X-RateLimit-Remaining` | Requests remaining in the current window. | | `X-RateLimit-Reset` | Absolute Unix timestamp (seconds since epoch) when the current rate-limit window resets. | When a request is throttled (`429`), responses also include `Retry-After` with seconds to wait before retrying. servers: - url: https://api.platform.dakota.xyz description: Production environment - url: https://api.platform.sandbox.dakota.xyz description: Sandbox — safe for testing with simulated data security: - ApiKeyAuth: [] tags: - name: Agentic Payments x-alpha: true description: >- Alpha — agent-driven payments: provision agents, draft and approve spending mandates, accept reviewed instructions, and manage scheduled payments. **Prerequisites:** Customer onboarded; signer groups attached for recognition. **Related:** Wallets, Signer Groups, Transactions - name: Mandates x-alpha: true description: >- Alpha — spending mandates: signed, signer-bound authorizations governing what may be spent, approved or cancelled by a second recognized signer (§8 — the dual-control rule that every mandate mutation must be signed by a recognized signer OTHER than the bound one). Independent of agents and scheduled payments. **Prerequisites:** Signer groups attached for recognition. **Related:** Signer Groups, Transactions - name: Insights x-alpha: true description: >- Alpha — read-only account insight: a deterministic report over a customer's agentic activity (funding balances, upcoming obligations, failures, mandate headroom and expiry) plus an advisory chat that narrates it. Never moves money, never creates or changes anything. **Prerequisites:** Customer onboarded; insight is computed from the customer's scheduled payments, mandates, and wallets. **Related:** Agentic Payments, Mandates - name: Customers description: >- Manage customer entities representing businesses and organizations onboarded to Dakota. **Prerequisites:** Complete KYB via Onboarding endpoints before initiating money movement. **Related:** Onboarding, Recipients, Transactions, Accounts, Wallets - name: Wallets description: >- Manage wallets, balances, and wallet-to-signer-group relationships for custody and movement controls. **Prerequisites:** Customer must exist. Configure signer groups before policy-enforced workflows. **Related:** Signer Groups, Policies, Transactions, Customers - name: Transactions description: >- Create, cancel, and retrieve transaction records across account and wallet flows. **Prerequisites:** Accounts or destinations must be configured based on flow type. **Related:** Accounts, Recipients, Policies, Events - name: Recipients description: >- Manage recipient entities and destination rails used by customers for payouts and transfers. **Prerequisites:** Customer must be onboarded and active. **Related:** Customers, Transactions, Accounts, Onboarding - name: Accounts description: >- Manage account resources used for onramp, offramp, and swap operations. **Prerequisites:** Customer must be created and network/asset constraints must be known. **Related:** Customers, Transactions, Auto Transactions, Info - name: Auto Transactions description: >- Manage automated transaction configurations and execution history for account automation workflows. **Prerequisites:** Source account must exist and be configured for automation. **Related:** Accounts, Transactions, Events - name: Onboarding description: >- Manage KYB/KYC onboarding lifecycle, application documents, attestations, and verification steps. **Prerequisites:** Customer context and required entity/application metadata. **Related:** Customers, Exceptions, Recipients, Transactions - name: Policies description: >- Define and manage policy objects and rules used for transaction governance and risk controls. **Prerequisites:** Wallet and signer group resources should be configured for enforcement scenarios. **Related:** Wallets, Signer Groups, Transactions - name: Signer Groups description: >- Manage signer groups and signer assignments for multi-party authorization models. **Prerequisites:** Wallets should exist before linking signer groups. **Related:** Wallets, Policies, Transactions - name: Authentication description: >- Manage API authentication credentials and key lifecycle for platform access. **Prerequisites:** Client organization must be provisioned. **Related:** Users, Info - name: Users description: >- Manage client users, roles, and identity metadata for platform access control. **Prerequisites:** Auth credentials and client context must be established. **Related:** Authentication - name: Webhooks description: >- Manage outbound webhook targets and delivery configuration for event notifications. **Prerequisites:** Subscriber endpoint must be reachable and secured. **Related:** Events, Authentication - name: Payouts description: >- Manage where Dakota sends your accrued developer-fee payouts. **Prerequisites:** Auth credentials and client context must be established. **Related:** Events - name: Events description: >- Retrieve event records emitted by platform operations for audit and troubleshooting. **Prerequisites:** Requesting client must have access to referenced resources. **Related:** Webhooks, Transactions, Onboarding - name: Info description: >- Read platform capability metadata, such as supported rails, networks, and assets. **Prerequisites:** Valid authentication headers. **Related:** Accounts, Transactions - name: Sandbox description: >- Trigger sandbox-only simulation endpoints for safe end-to-end integration testing with synthetic data. The sandbox host (`https://api.platform.sandbox.dakota.xyz`) also accepts a family of `X-Sandbox-*` request headers on most write endpoints (`Customers`, `Accounts`, `Transactions`, simulate endpoints) that let integrators drive deterministic failure modes — pick a preset via `X-Sandbox-Scenario`, or compose a custom one with `X-Sandbox-Error-Step`/`X-Sandbox-Error-Status`/`X-Sandbox-Error-Message`. `X-Sandbox-Instant-Completion` collapses async flows to a single synchronous step, and `X-Sandbox-Skip-Auto-Approval` keeps newly created KYB applications in `pending` for manual-review testing. All `X-Sandbox-*` headers are ignored in production. **Prerequisites:** Sandbox environment and test customer data. **Related:** Customers, Accounts, Transactions, Onboarding paths: /signer-groups/{signer_group_id}/signers: post: tags: - Signer Groups summary: Add a signer to a signer group description: Adds an existing signer to a signer group. operationId: createSignerGroupSigner parameters: - name: signer_group_id in: path required: true description: Signer Group ID schema: $ref: '#/components/schemas/KSUID' - $ref: '#/components/parameters/IdempotencyKeyHeader' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateSignerGroupSignerRequest' example: member_key: string responses: '200': description: Signer added successfully content: application/json: schema: $ref: '#/components/schemas/SignerGroup' example: id: 1NFHrqBHb3cTfLVkFSGmHZqdDPi client_id: 1NFHrqBHb3cTfLVkFSGmHZqdDPi name: My Wallet members: - id: 1NFHrqBHb3cTfLVkFSGmHZqdDPi client_id: 1NFHrqBHb3cTfLVkFSGmHZqdDPi name: Marc public_key: string key_type: ES256 '400': description: Bad request - invalid input data content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' example: type: https://docs.dakota.xyz/api-reference/errors#invalid-request title: Bad request - invalid input data status: 400 detail: Bad request - invalid input data instance: >- https://api.platform.dakota.xyz/signer-groups/example-id/signers request_id: req_01hzy6y7v8w9x0y1z2a3b4c5d6 '401': description: Unauthorized content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' example: type: >- https://docs.dakota.xyz/api-reference/errors#authentication-error title: Unauthorized status: 401 detail: Unauthorized instance: >- https://api.platform.dakota.xyz/signer-groups/example-id/signers request_id: req_01hzy6y7v8w9x0y1z2a3b4c5d6 '403': description: Forbidden content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' example: type: https://docs.dakota.xyz/api-reference/errors#forbidden title: Forbidden status: 403 detail: Forbidden instance: >- https://api.platform.dakota.xyz/signer-groups/example-id/signers request_id: req_01hzy6y7v8w9x0y1z2a3b4c5d6 '404': description: Signer Group not found content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' example: type: https://docs.dakota.xyz/api-reference/errors#not-found title: Signer Group not found status: 404 detail: Signer Group not found instance: >- https://api.platform.dakota.xyz/signer-groups/example-id/signers request_id: req_01hzy6y7v8w9x0y1z2a3b4c5d6 '409': description: Conflict - duplicate request detected content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' example: type: https://docs.dakota.xyz/api-reference/errors#conflict title: Conflict - duplicate request detected status: 409 detail: Conflict - duplicate request detected instance: >- https://api.platform.dakota.xyz/signer-groups/example-id/signers request_id: req_01hzy6y7v8w9x0y1z2a3b4c5d6 '500': description: Internal server error content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' example: type: https://docs.dakota.xyz/api-reference/errors#internal-error title: Internal server error status: 500 detail: Internal server error instance: >- https://api.platform.dakota.xyz/signer-groups/example-id/signers request_id: req_01hzy6y7v8w9x0y1z2a3b4c5d6 externalDocs: description: Read full guide in docs url: >- https://docs.dakota.xyz/api-reference/signer-groups/add-a-signer-to-a-signer-group components: schemas: KSUID: type: string title: KSUID description: >- KSUID is a 27-character globally unique ID that combines a timestamp with a random component. Used for all entity identifiers in the Dakota platform. pattern: ^[0-9A-Za-z]{27}$ minLength: 27 maxLength: 27 example: 1NFHrqBHb3cTfLVkFSGmHZqdDPi CreateSignerGroupSignerRequest: type: object required: - member_key properties: member_key: type: string description: Public key of the member to add to the signer group. SignerGroup: type: object description: Group of signers that dictates who can sign transactions for a wallet required: - id - client_id - name - members properties: id: $ref: '#/components/schemas/KSUID' client_id: $ref: '#/components/schemas/KSUID' name: type: string description: The wallet name example: My Wallet members: type: array description: Members that make up the signer group items: $ref: '#/components/schemas/Signer' removed_members: type: array description: | Signers previously in this group that have since been removed. Populated only when the request sets `include_removed=true`; each entry carries its `removed_at` timestamp. Omitted otherwise. items: $ref: '#/components/schemas/Signer' ProblemDetails: type: object required: - type - title - status description: | Error response following RFC 9457 Problem Details. Public API error responses use this format. example: type: https://docs.dakota.xyz/api-reference/errors#not-found title: Customer Not Found status: 404 detail: Customer cst_2abc123 was not found in your organization. instance: https://api.platform.dakota.xyz/customers/cst_2abc123 request_id: req_7f3a8b2c properties: type: type: string format: uri description: | URI reference identifying the problem type. Resolves to human-readable documentation. example: https://docs.dakota.xyz/api-reference/errors#not-found title: type: string description: >- Short, human-readable summary of the problem type. Stable across occurrences. example: Customer Not Found status: type: integer description: HTTP status code for this occurrence. example: 404 detail: type: string description: Human-readable explanation specific to this occurrence. example: Customer cst_2abc123 was not found in your organization. instance: type: string format: uri description: The request path that triggered this error. example: https://api.platform.dakota.xyz/customers/cst_2abc123 request_id: type: string description: Unique request identifier. Include when contacting support. example: req_7f3a8b2c errors: type: array description: Field-level validation errors (present for validation failures). items: $ref: '#/components/schemas/ValidationError' Signer: type: object description: >- A signer is a public key that can sign intents and it is part of a signer group required: - id - name - public_key - key_type properties: id: $ref: '#/components/schemas/KSUID' client_id: $ref: '#/components/schemas/KSUID' name: type: string description: The signer name example: Marc public_key: type: string description: | The signer public key. For KEY_TYPE_ES256 this must be a base64-encoded X.509 SubjectPublicKeyInfo (PKIX) for an ECDSA P-256 key. Both PEM-wrapped (with BEGIN/END PUBLIC KEY headers) and raw DER encodings are accepted. For KEY_TYPE_WEBAUTHN this must be a base64-encoded COSE public key. Only ES256 (EC2 / P-256, COSE alg -7) and RS256 (RSA, 2048-bit minimum, COSE alg -257) keys are supported; other algorithms and curves are rejected. See the WebAuthn & Passkey Signing guide for how each signatures[] entry is then built. key_type: type: string description: Type of the key enum: - ES256 - WEBAUTHN removed_at: type: integer format: int64 description: > Epoch seconds at which this signer was removed from the containing signer group. Present only for entries in a group's `removed_members` (i.e. when `include_removed=true`); absent for active members. ValidationError: type: object required: - field - message properties: field: type: string description: Field path using dot notation for nested fields. example: bank_account.routing_number message: type: string description: Human-readable description of the field error. example: Routing number must be exactly 9 digits code: type: string description: Machine-readable error code for this field. example: invalid_format parameters: IdempotencyKeyHeader: name: x-idempotency-key in: header required: true description: >- Unique key to ensure request idempotency. If the same key is used within a certain time window, the original response will be returned instead of executing the request again. schema: type: string format: uuid securitySchemes: ApiKeyAuth: type: apiKey in: header name: x-api-key ````