> ## Documentation Index > Fetch the complete documentation index at: https://nexus.gerowallet.io/docs/llms.txt > Use this file to discover all available pages before exploring further. # Decode a Cardano address into its credentials > Splits a Cardano address into its structural parts: era, network, type and the payment / stake credentials. Accepts Shelley-era bech32 (addr1, addr_test1, stake1, stake_test1) and Byron-era base58 (Ddz, Ae2). This is pure computation on the address string, with no chain lookup: the network query parameter is accepted for consistency with the rest of the API and ignored, and the reported network is the one the address itself encodes. Byron addresses report era and type 'byron' with no credentials, because their spending data is a CBOR-enveloped key hash rather than a Shelley credential, and with no network: Byron encodes it as an optional protocol-magic attribute inside that envelope, which is not parsed here, so the field is omitted rather than guessed. Pointer addresses report the payment credential only; the (slot, txIndex, certIndex) pointer target is not resolved. ## OpenAPI ````yaml https://nexus.gerowallet.io/v3/api-docs get /api/addresses/decode/{address} openapi: 3.1.0 info: title: Nexus API description: >- Multi-chain blockchain data API for Cardano (and Apex), Bitcoin, and Midnight. ## Blockchains & Networks Endpoints are grouped by **blockchain**. Pick the target **network** with the `network` query parameter. A network is an environment *within* a blockchain, not a separate endpoint family. - **Cardano & Apex**: one shared set of UTxO endpoints serves `CARDANO_MAINNET`, `CARDANO_PREPROD`, `CARDANO_PREVIEW`, `APEX_PRIME_MAINNET`, `APEX_VECTOR_MAINNET`, `APEX_VECTOR_TESTNET` - **Bitcoin**: `BITCOIN_MAINNET`, `BITCOIN_TESTNET4` - **Midnight**: `MIDNIGHT_MAINNET`, `MIDNIGHT_PREPROD`, `MIDNIGHT_STAGENET` These are the values published on each operation's `network` schema, and what generated clients send. A kebab-case alias (`cardano-mainnet`) is also accepted, and matching is case-insensitive — see the note on the parameter itself. ### Key scope: one chain, one network Each API key is scoped to **one chain and one network**, fixed at creation time. A `CARDANO_MAINNET` key cannot query `CARDANO_PREPROD`, and it cannot query Bitcoin or Midnight at all. Create one key per chain and network under the same account. Sending a `network` value that does not match the key returns **400 Network Mismatch**; omit the parameter and the request runs against the key's own network. What is uniform across chains is the integration surface, not the credential: one account, one base URL, one auth header, one docs site. ## Authentication Send your API key in the `X-Api-Key` header. This is the credential for programmatic access (create one in the dashboard; keys start with `nxs_`). `Authorization: Bearer ` is only for JWT **session** tokens issued by `/api/auth/login` (browser/mobile apps), not for API keys. ## Add-ons Capability is gated separately from network scope. Market data, wallet analytics, transaction building, MCP, and IPFS are paid add-ons; those endpoints return **402 Payment Required** on a key whose plan does not carry the matching add-on, even when the chain and network match. contact: name: Nexus Team url: https://nexus.gerowallet.io/support email: nexus@gerowallet.io license: name: Apache 2.0 url: https://www.apache.org/licenses/LICENSE-2.0.html version: 1.0.0 servers: - url: https://nexus.gerowallet.io description: API Server security: - apiKeyAuth: [] - bearerAuth: [] tags: - name: Cardano · Blocks description: Cardano Block API - name: Cardano · Policy description: Cardano Policy API - name: IPFS description: IPFS Content Resolution API - name: Bitcoin · Ordinals description: Ordinals + runes metadata (ord indexer) - name: Partner description: Aggregator revenue share for partner key holders - name: Cardano · Metadata description: Label-scoped transaction metadata API - name: Cardano · Assets description: Token Registry Metadata - name: Cardano · Transactions description: Cardano Transactions API - name: Midnight · Transactions description: Midnight-specific transaction endpoints (unshielded UTXOs) - name: Bitcoin · Mempool description: Bitcoin mempool snapshot - name: Midnight · DUST description: DUST registration + generation status - name: Cardano · Stake Pools description: >- Cardano stake pool information including registrations, retirements, and pool metadata - name: Cardano · Network description: Cardano Network API - Query static network / genesis parameters - name: Cardano · Addresses description: Cardano Address API - name: Bitcoin · Addresses description: >- Bitcoin address-keyed queries: stats / balance / UTxOs via electrs; ordinals via ord - name: Bitcoin · Transactions description: Bitcoin transaction lookup and submission - name: Cardano · Governance description: >- Cardano on-chain governance: DReps, governance actions + votes, constitutional committee, constitution - name: Cardano · DReps description: >- Cardano delegate representatives (DReps): voting power, status, metadata, delegators - name: Cardano · Transaction Builder description: >- Cardano transaction building API. Builds unsigned transactions server-side for client-side signing and submission. Network can be specified in the request body or as a query parameter. Body takes precedence over query parameter. - name: Cardano · Assets description: Cardano Asset API - name: Cardano · Accounts description: Cardano Account API - name: Bitcoin · Fees description: Bitcoin fee-rate estimates by confirmation block target - name: Bitcoin · Blocks description: Bitcoin block lookup - name: Cardano · Handles description: ADA Handle resolution - name: Cardano Market Data description: Endpoints from cardano-market-data - name: Midnight · Indexer description: Transparent proxy to the Midnight GraphQL indexer - name: Cardano · Scripts description: Cardano script & datum API - name: Cardano · Epochs description: Cardano Epoch API - Query protocol parameters and epoch information - name: Bitcoin · Chain description: Bitcoin chain-tip and sync state paths: /api/addresses/decode/{address}: get: tags: - Cardano · Addresses summary: Decode a Cardano address into its credentials description: >- Splits a Cardano address into its structural parts: era, network, type and the payment / stake credentials. Accepts Shelley-era bech32 (addr1, addr_test1, stake1, stake_test1) and Byron-era base58 (Ddz, Ae2). This is pure computation on the address string, with no chain lookup: the network query parameter is accepted for consistency with the rest of the API and ignored, and the reported network is the one the address itself encodes. Byron addresses report era and type 'byron' with no credentials, because their spending data is a CBOR-enveloped key hash rather than a Shelley credential, and with no network: Byron encodes it as an optional protocol-magic attribute inside that envelope, which is not parsed here, so the field is omitted rather than guessed. Pointer addresses report the payment credential only; the (slot, txIndex, certIndex) pointer target is not resolved. operationId: decodeAddress parameters: - name: network in: query description: Accepted and ignored. Decoding never consults a network. required: false schema: type: string default: '' - name: address in: path required: true schema: type: string maxLength: 200 minLength: 1 pattern: ^[a-zA-Z0-9_]+$ responses: '200': description: Address decoded content: application/json: schema: $ref: '#/components/schemas/AddressDecodeDto' additionalProperties: default: '' default: '' '400': description: Not a valid Cardano address content: application/json: schema: type: string additionalProperties: default: '' default: '' example: error: Not a valid Cardano address components: schemas: AddressDecodeDto: type: object default: null description: Decoded components of a Cardano address properties: address: type: string default: '' description: The address exactly as decoded (whitespace-trimmed) example: >- addr1qx2fxv2umyhttkxyxp8x0dlpdt3k6cwng5pxj3jhsydzer3n0d3vllmyqwsx5wktcd8cc3sq835lu7drv2xwl2wywfgse35a3x era: type: string default: '' description: Address-format era. Every post-Byron format is 'shelley'. enum: - shelley - byron example: shelley network: type: string default: '' description: >- Network the address encodes. Absent for Byron addresses: Byron carries its network as an optional protocol-magic attribute inside the address's CBOR envelope, and that parsing is not performed here, so the network is reported as undetermined rather than guessed. enum: - mainnet - testnet example: mainnet type: type: string default: '' description: Address type enum: - base - enterprise - pointer - reward - byron example: base paymentCredential: $ref: '#/components/schemas/AddressCredentialDto' default: '' description: Payment (spending) credential. Null for reward and Byron addresses. stakeCredential: $ref: '#/components/schemas/AddressCredentialDto' default: '' description: >- Stake (delegation) credential. Null for enterprise, pointer and Byron addresses. For a reward address this holds the address's single credential and paymentCredential is null. AddressCredentialDto: type: object default: null description: A Cardano address credential (key hash or script hash) properties: kind: type: string default: '' description: Credential kind enum: - key - script example: key hash: type: string default: '' description: Hex-encoded 28-byte credential hash example: 9493315cd92eb5d8c4304e67b7e16ae36d61d34502694657811a2c8e securitySchemes: apiKeyAuth: type: apiKey description: >- ### API key (programmatic access — recommended) Send your API key in the `X-Api-Key` header. Keys start with `nxs_` and are created in the dashboard (or via **POST /api/keys** with a session JWT). Each key is scoped to **one chain and one network** (for example `CARDANO_MAINNET`), fixed at creation time. It cannot query a different network on the same chain, and it cannot query a different chain at all. A mismatched `network` parameter returns **400 Network Mismatch**. Create one key per chain and network under the same account. This is the credential most integrations should use. name: X-Api-Key in: header bearerAuth: type: http description: >- ### JWT session token (browser / mobile apps) A short-lived JWT issued by `/api/auth/login` or `/api/auth/device`, sent as `Authorization: Bearer `. This is the **session** credential for the web dashboard and mobile apps, not for server-to-server API access. For programmatic API access use an **API key** in the `X-Api-Key` header instead — do **not** put an `nxs_` API key in this Bearer field. scheme: bearer bearerFormat: JWT ````