Sponge · Authentication Profile

Sponge Authentication

Authentication

Sponge's public Wallet API authenticates with a per-agent bearer API key. A browser device flow issues agent credentials interactively; agent keys are used non-interactively for servers/CI. Separately, an OAuth 2.0 / OIDC authorization server (S256 PKCE, dynamic client registration) fronts the hosted MCP servers for connectors that support OAuth.

Sponge secures its APIs with http, oauth2, and openIdConnect across 4 declared security schemes, as derived from its OpenAPI definitions. OAuth 2.0 is offered via the authorizationCode flow(s).

CompanyAgent PaymentsAI AgentsWalletsCryptocurrencyPaymentsStablecoinsx402MPPFinancial InfrastructureMCPFintechCardsOnramp
Methods: http, oauth2, openIdConnect Schemes: 4 OAuth flows: authorizationCode API key in:

Security Schemes

bearerAuth http
scheme: bearer
DeviceFlow oauth2-device
OAuth2 oauth2
SIWE eip-4361

Source

Authentication Profile

Raw ↑ 
generated: '2026-07-21'
method: searched
source: openapi/sponge-openapi-original.json
docs: https://docs.paysponge.com/wallet/ai-agents.md
description: >-
  Sponge's public Wallet API authenticates with a per-agent bearer API key. A
  browser device flow issues agent credentials interactively; agent keys are used
  non-interactively for servers/CI. Separately, an OAuth 2.0 / OIDC authorization
  server (S256 PKCE, dynamic client registration) fronts the hosted MCP servers
  for connectors that support OAuth.
summary:
  types:
  - http
  - oauth2
  - openIdConnect
  api_key_prefixes: [sponge_live_, sponge_test_]
  oauth2_flows: [authorizationCode]
schemes:
- name: bearerAuth
  type: http
  scheme: bearer
  bearerFormat: API Key
  key_prefixes: [sponge_live_, sponge_test_]
  env: SPONGE_API_KEY
  sources:
  - openapi/sponge-openapi-original.json
  - https://docs.paysponge.com/wallet/ai-agents.md
- name: DeviceFlow
  type: oauth2-device
  description: SpongeWallet.connect() starts a browser-based device flow when no local credentials exist; credentials cached at ~/.spongewallet/credentials.json with owner-only permissions.
  sources:
  - https://docs.paysponge.com/wallet/ai-agents.md
- name: OAuth2
  type: oauth2
  description: OAuth 2.0 authorization-code flow (S256 PKCE, dynamic client registration) fronting the hosted MCP servers.
  authorization_url: https://api.wallet.paysponge.com/oauth/authorize
  token_url: https://api.wallet.paysponge.com/oauth/token
  scopes_ref: scopes/sponge-scopes.yml
  sources:
  - well-known/sponge-openid-configuration.json
- name: SIWE
  type: eip-4361
  description: Sign-In With Ethereum (EIP-4361) signatures for endpoints that require them (POST /api/siwe/generate).
  sources:
  - https://sponge.md