Polkadot transaction API

openapi: 3.2.0
info:
  title: Polkadot Transaction API
  version: '1.0'
  description: 'Operations tagged transaction across 2 of this provider''s published API definitions: polkadot-rest-api-openapi.json, substrate-api-sidecar-openapi.yaml. Each path carries the servers of the definition it was published in.'
servers:
- url: http://localhost:8080/v1
  description: Localhost
- url: https://polkadot-public-sidecar.parity-chains.parity.io/
  description: Polkadot Parity public sidecar
- url: https://kusama-public-sidecar.parity-chains.parity.io/
  description: Kusama Parity public sidecar
- url: https://polkadot-asset-hub-public-sidecar.parity-chains.parity.io/
  description: Polkadot Asset Hub Parity public sidecar
- url: https://kusama-asset-hub-public-sidecar.parity-chains.parity.io/
  description: Kusama Asset Hub Parity public sidecar
- url: http://localhost:8080
  description: Localhost
tags:
- name: transaction
  description: Transaction submission, fee estimation, and construction material
paths:
  /v1/transaction:
    post:
      tags:
      - transaction
      summary: Submit transaction
      description: Submit a signed extrinsic to the transaction pool.
      operationId: submit
      requestBody:
        description: Signed extrinsic with 'tx' field containing hex-encoded transaction
        content:
          application/json:
            schema:
              type: object
        required: true
      responses:
        '200':
          description: Transaction hash
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Invalid transaction
        '500':
          description: Internal server error
        '503':
          description: Service unavailable
    servers:
    - url: http://localhost:8080/v1
      description: Localhost
  /v1/transaction/dry-run:
    post:
      tags:
      - transaction
      summary: Dry run transaction
      description: Dry run a transaction to check validity without submitting.
      operationId: dry_run
      requestBody:
        description: Transaction with 'tx', 'senderAddress', and optional 'at' and 'xcmVersion' fields
        content:
          application/json:
            schema:
              type: object
        required: true
      responses:
        '200':
          description: Dry run result
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Invalid transaction
        '500':
          description: Internal server error
        '503':
          description: Service unavailable
    servers:
    - url: http://localhost:8080/v1
      description: Localhost
  /v1/transaction/fee-estimate:
    post:
      tags:
      - transaction
      summary: Estimate transaction fee
      description: Estimate the fee for a transaction.
      operationId: fee_estimate
      requestBody:
        description: Transaction with 'tx' field containing hex-encoded transaction
        content:
          application/json:
            schema:
              type: object
        required: true
      responses:
        '200':
          description: Fee estimate
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FeeEstimateResponse'
        '400':
          description: Invalid transaction
        '500':
          description: Internal server error
        '503':
          description: Service unavailable
    servers:
    - url: http://localhost:8080/v1
      description: Localhost
  /v1/transaction/material:
    get:
      tags:
      - transaction
      summary: Transaction construction material
      description: Returns network information needed for transaction construction including genesis hash, spec version, and optionally metadata.
      operationId: material
      parameters:
      - name: at
        in: query
        description: Block hash or number to query at
        required: false
        schema:
          type: string
      - name: noMeta
        in: query
        description: 'DEPRECATED: If true, metadata is not included'
        required: false
        schema:
          type: boolean
      - name: metadata
        in: query
        description: 'Metadata format: ''json'' or ''scale'''
        required: false
        schema:
          type: string
      responses:
        '200':
          description: Transaction material
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Invalid parameters
        '500':
          description: Internal server error
        '503':
          description: Service unavailable
    servers:
    - url: http://localhost:8080/v1
      description: Localhost
  /v1/transaction/material/{metadataVersion}:
    get:
      tags:
      - transaction
      summary: Transaction material with versioned metadata
      description: Returns transaction construction material with metadata at a specific version.
      operationId: material_versioned
      parameters:
      - name: metadataVersion
        in: path
        description: Metadata version (e.g., 'v14', 'v15')
        required: true
        schema:
          type: string
      - name: at
        in: query
        description: Block hash or number to query at
        required: false
        schema:
          type: string
      - name: noMeta
        in: query
        description: 'DEPRECATED: If true, metadata is not included'
        required: false
        schema:
          type: boolean
      - name: metadata
        in: query
        description: 'Metadata format: ''json'' or ''scale'''
        required: false
        schema:
          type: string
      responses:
        '200':
          description: Transaction material with versioned metadata
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Invalid parameters
        '500':
          description: Internal server error
        '503':
          description: Service unavailable
    servers:
    - url: http://localhost:8080/v1
      description: Localhost
  /v1/transaction/metadata-blob:
    post:
      tags:
      - transaction
      summary: Generate metadata blob
      description: Generates a metadata blob for transaction signing with the CheckMetadataHash extension.
      operationId: metadata_blob
      requestBody:
        description: Request with 'tx' field and optional 'at' block
        content:
          application/json:
            schema:
              type: object
        required: true
      responses:
        '200':
          description: Metadata blob
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Invalid parameters
        '500':
          description: Internal server error
        '503':
          description: Service unavailable
    servers:
    - url: http://localhost:8080/v1
      description: Localhost
  /v1/transaction/parse:
    post:
      tags:
      - transaction
      summary: Parse transaction
      description: 'Decode a raw transaction and return its components without executing or submitting it. Returns the decoded pallet/method, call arguments, signature info, nonce, tip, era, and hash. Note: This endpoint uses the chain''s current (latest) metadata for decoding. Transactions created for older runtime versions may fail to decode if the extrinsic format has changed.'
      operationId: parse
      requestBody:
        description: Transaction with 'tx' field containing hex-encoded extrinsic
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ParseRequest'
        required: true
      responses:
        '200':
          description: Parsed transaction
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ParseResponse'
        '400':
          description: Invalid transaction
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ParseError'
        '500':
          description: Internal server error
    servers:
    - url: http://localhost:8080/v1
      description: Localhost
  /transaction:
    post:
      tags:
      - transaction
      summary: Submit a transaction to the node's transaction pool.
      description: Accepts a valid signed extrinsic. Replaces `/tx` from versions < v1.0.0.
      operationId: submitTransaction
      requestBody:
        $ref: '#/components/requestBodies/Transaction'
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionSuccess'
        '400':
          description: failed to parse or submit transaction
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionFailure'
    servers:
    - url: https://polkadot-public-sidecar.parity-chains.parity.io/
      description: Polkadot Parity public sidecar
    - url: https://kusama-public-sidecar.parity-chains.parity.io/
      description: Kusama Parity public sidecar
    - url: https://polkadot-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Polkadot Asset Hub Parity public sidecar
    - url: https://kusama-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Kusama Asset Hub Parity public sidecar
    - url: http://localhost:8080
      description: Localhost
  /transaction/dry-run:
    post:
      tags:
      - transaction
      summary: Dry run an extrinsic.
      description: Use the `dryRun` call to simulate the submission of a transaction without executing it so that you can check for potential errors and validate the expected outcome.
      operationId: dryrunTransaction
      requestBody:
        $ref: '#/components/requestBodies/TransactionDryRun'
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionDryRun'
        '400':
          description: failed to dry-run transaction
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionFailure'
    servers:
    - url: https://polkadot-public-sidecar.parity-chains.parity.io/
      description: Polkadot Parity public sidecar
    - url: https://kusama-public-sidecar.parity-chains.parity.io/
      description: Kusama Parity public sidecar
    - url: https://polkadot-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Polkadot Asset Hub Parity public sidecar
    - url: https://kusama-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Kusama Asset Hub Parity public sidecar
    - url: http://localhost:8080
      description: Localhost
  /transaction/fee-estimate:
    post:
      tags:
      - transaction
      summary: Receive a fee estimate for a transaction.
      description: 'Send a serialized transaction and receive back a naive fee estimate. Note: `partialFee` does not include any tips that you may add to increase a transaction''s priority. See the reference on `compute_fee`. Replaces `/tx/fee-estimate` from versions < v1.0.0. Substrate Reference: - `RuntimeDispatchInfo`: https://crates.parity.io/pallet_transaction_payment_rpc_runtime_api/struct.RuntimeDispatchInfo.html - `query_info`: https://crates.parity.io/pallet_transaction_payment/struct.Module.html#method.query_info - `compute_fee`: https://crates.parity.io/pallet_transaction_payment/struct.Module.html#method.compute_fee'
      operationId: feeEstimateTransaction
      requestBody:
        $ref: '#/components/requestBodies/Transaction'
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionFeeEstimate'
        '400':
          description: fee estimation failure
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionFeeEstimateFailure'
    servers:
    - url: https://polkadot-public-sidecar.parity-chains.parity.io/
      description: Polkadot Parity public sidecar
    - url: https://kusama-public-sidecar.parity-chains.parity.io/
      description: Kusama Parity public sidecar
    - url: https://polkadot-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Polkadot Asset Hub Parity public sidecar
    - url: https://kusama-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Kusama Asset Hub Parity public sidecar
    - url: http://localhost:8080
      description: Localhost
  /transaction/material:
    get:
      tags:
      - transaction
      summary: Get all the network information needed to construct a transaction offline.
      description: Returns the material that is universal to constructing any signed transaction offline. Replaces `/tx/artifacts` from versions < v1.0.0.
      operationId: getTransactionMaterial
      parameters:
      - name: at
        in: query
        description: Block at which to retrieve the transaction construction material.
        required: false
        schema:
          type: string
          description: Block identifier, as the block height or block hash.
          format: unsignedInteger or $hex
      - name: noMeta
        in: query
        description: DEPRECATED! This is no longer supported
        schema:
          type: boolean
          default: false
      - name: metadata
        in: query
        description: Specifies the format of the metadata to be returned. Accepted values are 'json', and 'scale'. 'json' being the decoded metadata, and 'scale' being the SCALE encoded metadata. When `metadata` is not inputted, the `metadata` field will be absent.
        schema:
          type: string
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionMaterial'
        '400':
          description: invalid blockId supplied for at query param
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
    servers:
    - url: https://polkadot-public-sidecar.parity-chains.parity.io/
      description: Polkadot Parity public sidecar
    - url: https://kusama-public-sidecar.parity-chains.parity.io/
      description: Kusama Parity public sidecar
    - url: https://polkadot-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Polkadot Asset Hub Parity public sidecar
    - url: https://kusama-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Kusama Asset Hub Parity public sidecar
    - url: http://localhost:8080
      description: Localhost
  /transaction/material/{metadataVersion}:
    get:
      tags:
      - transaction
      summary: Get all the network information needed to construct a transaction offline and the version of metadata specified in `metadataVersion`.
      description: Returns all the materials necessary for constructing any signed transactions offline.
      operationId: getTransactionMaterialwithVersionedMetadata
      parameters:
      - name: metadataVersion
        in: path
        description: The version of metadata. The input is expected in a `vX` format, where `X` represents the version number (e.g. `v14`, `v15`). By default, metadata is outputted in 'json' format, unless the `metadata` query parameter is provided, in which case it can be either in 'json' or 'scale' format.
        required: true
        schema:
          type: string
      - name: at
        in: query
        description: Block at which to retrieve the transaction construction material.
        required: false
        schema:
          type: string
          description: Block identifier, as the block height or block hash.
          format: unsignedInteger or $hex
      - name: metadata
        in: query
        description: Specifies the format of the metadata to be returned. Accepted values are 'json', and 'scale'. 'json' being the decoded metadata, and 'scale' being the SCALE encoded metadata.
        schema:
          type: string
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionMaterial'
        '400':
          description: invalid blockId supplied for at query param
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
    servers:
    - url: https://polkadot-public-sidecar.parity-chains.parity.io/
      description: Polkadot Parity public sidecar
    - url: https://kusama-public-sidecar.parity-chains.parity.io/
      description: Kusama Parity public sidecar
    - url: https://polkadot-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Polkadot Asset Hub Parity public sidecar
    - url: https://kusama-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Kusama Asset Hub Parity public sidecar
    - url: http://localhost:8080
      description: Localhost
  /transaction/metadata-blob:
    post:
      tags:
      - transaction
      summary: Get the metadata blob for offline signers.
      description: Returns the minimal metadata ("metadata blob" or "proof") needed by offline signers to decode a transaction's signing payload, along with the metadata hash for the CheckMetadataHash signed extension per RFC-0078.
      operationId: getTransactionMetadataBlob
      requestBody:
        $ref: '#/components/requestBodies/TransactionMetadataBlob'
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransactionMetadataBlob'
        '400':
          description: invalid request body or metadata V15 not available
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
    servers:
    - url: https://polkadot-public-sidecar.parity-chains.parity.io/
      description: Polkadot Parity public sidecar
    - url: https://kusama-public-sidecar.parity-chains.parity.io/
      description: Kusama Parity public sidecar
    - url: https://polkadot-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Polkadot Asset Hub Parity public sidecar
    - url: https://kusama-asset-hub-public-sidecar.parity-chains.parity.io/
      description: Kusama Asset Hub Parity public sidecar
    - url: http://localhost:8080
      description: Localhost
components:
  schemas:
    Weight:
      type: object
      required:
      - refTime
      - proofSize
      properties:
        proofSize:
          type: string
        refTime:
          type: string
    SignerId:
      type: object
      description: Signer identifier.
      required:
      - id
      properties:
        id:
          type: string
          description: SS58-encoded account address
          example: 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY
    MethodInfo:
      type: object
      description: Method information (pallet and method name).
      required:
      - pallet
      - method
      properties:
        method:
          type: string
          description: Method name in lowerCamelCase
          example: transferAllowDeath
        pallet:
          type: string
          description: Pallet name in lowerCamelCase
          example: balances
    FeeEstimateResponse:
      type: object
      required:
      - weight
      - class
      - partialFee
      properties:
        class:
          type: string
        partialFee:
          type: string
        weight:
          $ref: '#/components/schemas/Weight'
    ParseRequest:
      type: object
      description: Request body for transaction parsing.
      properties:
        tx:
          type:
          - string
          - 'null'
          description: Hex-encoded extrinsic with optional 0x prefix.
          example: 0x4902840004316d995f...
    ParseError:
      type: object
      description: Error response for transaction parsing failures.
      required:
      - code
      - error
      - transaction
      - cause
      - stack
      properties:
        cause:
          type: string
          description: Cause of the error
        code:
          type: integer
          format: int32
          description: HTTP status code
          example: 400
          minimum: 0
        error:
          type: string
          description: Error message
          example: Failed to parse transaction.
        stack:
          type: string
          description: Stack trace
        transaction:
          type: string
          description: The transaction that failed to parse
    SignatureInfo:
      type: object
      description: Signature information for signed extrinsics.
      required:
      - signer
      - signature
      properties:
        signature:
          type: string
          description: Hex-encoded signature
          example: 0xa24152685f52e4726466e80247d965bb3d349637fc8a1ea6f7cc1451ddec98b5...
        signer:
          $ref: '#/components/schemas/SignerId'
          description: Signer account
    ParseResponse:
      type: object
      description: Response for successful transaction parsing.
      required:
      - isSigned
      - method
      - args
      - era
      - hash
      properties:
        args:
          type: object
          description: Decoded call arguments
        era:
          type: object
          description: Era/mortality information
        hash:
          type: string
          description: Blake2-256 hash of the extrinsic
          example: 0x1234567890abcdef...
        isSigned:
          type: boolean
          description: Whether the extrinsic is signed
          example: true
        method:
          $ref: '#/components/schemas/MethodInfo'
          description: Pallet and method information
        nonce:
          type:
          - string
          - 'null'
          description: Account nonce (only present for signed extrinsics)
          example: '42'
        signature:
          oneOf:
          - type: 'null'
          - $ref: '#/components/schemas/SignatureInfo'
            description: Signature information (only present for signed extrinsics)
        tip:
          type:
          - string
          - 'null'
          description: Tip amount (only present for signed extrinsics)
          example: '0'
    WeightsV2:
      type: object
      properties:
        refTime:
          type: string
          description: The weight of computational time used based on some reference hardware.
        proofSize:
          type: string
          description: The weight of storage space used by proof of validity.
    MetadataBlobBody:
      type: object
      properties:
        tx:
          type: string
          format: hex
          description: Full encoded extrinsic as a hex string.
        txAdditionalSigned:
          type: string
          format: hex
          description: Optional additional signed data for the extrinsic. Used together with `tx`.
        callData:
          type: string
          format: hex
          description: Call data as hex string. Use this alongside includedInExtrinsic and includedInSignedData instead of `tx`.
        includedInExtrinsic:
          type: string
          format: hex
          description: Signed extension data included in the extrinsic. Required when using callData.
        includedInSignedData:
          type: string
          format: hex
          description: Signed extension data included in the signature. Required when using callData.
        at:
          type: string
          description: Block hash or number to query at. Defaults to finalized head.
          format: unsignedInteger or $hex
      description: 'Request body for generating the metadata blob. You must provide either: (1) `tx` (full extrinsic) with optional `txAdditionalSigned`, or (2) `callData` with `includedInExtrinsic` and `includedInSignedData`.'
    TransactionDryRun:
      type: object
      properties:
        resultType:
          type: string
          enum:
          - DispatchOutcome
          - DispatchError
          - TransactionValidityError
          description: The result will be either a `DispatchOutcome` if the transaction is valid, a `DispatchError` if the transaction failed, or a `TransactionValidityError` if the transaction is invalid.
        result:
          oneOf:
          - $ref: '#/components/schemas/TransactionDispatchOutcome'
          - $ref: '#/components/schemas/TransactionDispatchError'
          - $ref: '#/components/schemas/TransactionValidityError'
      description: "References:\n  - `PostDispatchInfo`: https://docs.rs/frame-support/38.0.0/frame_support/dispatch/struct.PostDispatchInfo.html\n  - `DispatchError`: https://docs.rs/sp-runtime/39.0.1/sp_runtime/enum.DispatchError.html\n  - `Error Type`: https://paritytech.github.io/polkadot-sdk/master/xcm_runtime_apis/dry_run/enum.Error.html"
    TransactionValidityError:
      type: object
      description: The error result from an invalid transaction submitted via the `dry-run` endpoint.
      properties:
        errorType:
          type: string
          enum:
          - Unimplemented
          - VersionedConversionFailed
          description: The type of transaction error, either `Unimplemented` or `VersionedConversionFailed`.
    DryRunBody:
      type: object
      properties:
        at:
          type: string
          format: unsignedInteger
        tx:
          type: string
          format: hex
        senderAddress:
          type: string
          format: ss58
    TransactionFeeEstimate:
      type: object
      properties:
        weight:
          $ref: '#/components/schemas/WeightsV2'
          description: Weights represented as WeightsV2 (two dimensional weights). When querying historical blocks that use WeightsV1, the weight will be returned as a weight key that points to a number represented as a string.
        class:
          type: string
          description: Extrinsic class.
          enum:
          - Normal
          - Operational
          - Mandatory
        partialFee:
          type: string
          description: Expected inclusion fee for the transaction. Note that the fee rate changes up to 30% in a 24 hour period and this will not be the exact fee.
          format: unsignedInteger
      description: 'Note: `partialFee` does not include any tips that you may add to increase a transaction''s priority. See [compute_fee](https://crates.parity.io/pallet_transaction_payment/struct.Module.html#method.compute_fee).'
    TransactionSuccess:
      type: object
      properties:
        hash:
          type: string
          description: The hash of the encoded transaction.
    TransactionDispatchOutcome:
      type: object
      description: The result of a valid transaction submitted via the `dry-run` endpoint.
      properties:
        actualWeight:
          type: string
          format: unsignedInteger
          description: The actual weight of the transaction.
        paysFee:
          type: string
          format: boolean
          description: Whether the transaction pays a fee.
    TransactionFailure:
      oneOf:
      - $ref: '#/components/schemas/TransactionFailedToSubmit'
      - $ref: '#/components/schemas/TransactionFailedToParse'
    TransactionFailedToSubmit:
      type: object
      properties:
        code:
          type: number
        error:
          type: string
          description: Failed to submit transaction.
        transaction:
          type: string
          format: hex
        cause:
          type: string
        stack:
          type: string
      description: Error message when the node rejects the submitted transaction.
    TransactionFailedToParse:
      type: object
      properties:
        code:
          type: number
        error:
          type: string
          description: '`Failed to parse a tx.`'
        transaction:
          type: string
          format: hex
        cause:
          type: string
        stack:
          type: string
      description: Error message when Sidecar fails to parse the transaction.
    TransactionMaterial:
      type: object
      properties:
        at:
          $ref: '#/components/schemas/BlockIdentifiers'
        genesisHash:
          type: string
          description: The hash of the chain's genesis block.
          format: blockHash
        chainName:
          type: string
          description: The chain's name.
        specName:
          type: string
          description: The chain's spec.
        specVersion:
          type: string
          description: The spec version. Always increased in a runtime upgrade.
        txVersion:
          type: string
          description: The transaction version. Common `txVersion` numbers indicate that the transaction encoding format and method indices are the same. Needed for decoding in an offline environment. Adding new transactions does not change `txVersion`.
        metadata:
          type: string
          description: The chain's metadata. It will only be present when the metadata query param is used.
      description: 'Note: `chainName`, `specName`, and `specVersion` are used to define a type registry with a set of signed extensions and types. For Polkadot and Kusama, `chainName` is not used in defining this registry, but in other Substrate-based chains that re-launch their network without changing the `specName`, the `chainName` would be needed to create the correct registry. Substrate Reference: - `RuntimeVersion`: https://crates.parity.io/sp_version/struct.RuntimeVersion.html - `SignedExtension`: https://crates.parity.io/sp_runtime/traits/trait.SignedExtension.html -  FRAME Support: https://crates.parity.io/frame_support/metadata/index.html'
    TransactionDispatchError:
      type: object
      description: The reason why the dispatch call failed.
      properties:
        errorType:
          type: string
          enum:
          - Other
          - CannotLookup
          - BadOrigin
          - ModuleError
          - ConsumerRemaining
          - NoProviders
          - TooManyConsumers
          - TokenError
          - ArithmeticError
          - TransactionalError
          - Exhausted
          - Corruption
          - Unavailable
          - RootNotAllowed
          description: The type of transaction error.
    Error:
      type: object
      properties:
        code:
          type: number
        message:
          type: string
        stack:
          type: string
        level:
          type: string
    BlockIdentifiers:
      type: object
      properties:
        hash:
          type: string
          description: The block's hash.
          format: hex
        height:
          type: string
          description: The block's height.
          format: unsignedInteger
    TransactionFeeEstimateFailure:
      type: object
      properties:
        code:
          type: number
        at:
          type: object
          properties:
            hash:
              type: string
        error:
          type: string
          description: Error description.
        transaction:
          type: string
          format: hex
        block:
          type: string
          description: Block hash of the block fee estimation was attempted at.
        cause:
          type: string
          description: Error message from the client.
        stack:
          type: string
    Transaction:
      type: object
      properties:
        tx:
          type: string
          format: hex
    TransactionMetadataBlob:
      type: object
      properties:
        at:
          $ref: '#/components/schemas/BlockIdentifiers'
        metadataHash:
          type: string
          format: hex
          description: The 32-byte metadata hash (hex-encoded) that should be used with the CheckMetadataHash signed extension.
        metadataBlob:
          type: string
          format: hex
          description: The metadata blob (hex-encoded) containing the minimal metadata required for offline signers t

# --- truncated at 32 KB (33 KB total) ---
# Full source: https://raw.githubusercontent.com/api-evangelist/polkadot/refs/heads/main/openapi/polkadot-transaction-api-openapi.yml