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The REST API is a JSON mapping of the gRPC API. Both expose the same messages, so every field has one type and two encodings: its protobuf type over gRPC, and the JSON value described below over REST.

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JSON conventions

  • Requests and responses use Content-Type: application/json and UTF-8.
  • Responses use lowerCamelCase field names (vaultUuid). Requests also accept the snake_case name (vault_uuid). Unknown request fields are ignored without an error, so a misspelled optional field is read as omitted: for example, a misspelled callbackClientSignerPublicKey sends a transaction or structured message request to the MPCVault app for manual signing.
  • Every field of a message is present in a response. A scalar that is unset has its zero value ("", "0", false, the first enum value, []). A message or wrapper that is unset is null.
  • A field that belongs to a oneof is present only when it is set, so a response contains at most one of the members.
  • Field order is not significant.
  • The OpenAPI schemas list the canonical form: lowerCamelCase names, enum names and decimal strings for 64-bit integers. The other forms in the table below are accepted but not listed.

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Types

An enum can gain values. Treat a name you do not recognize as unknown instead of failing.

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Field conventions

These conventions hold across the API. A field that follows another rule says so in its description.
  • Timestamps are Unix time in milliseconds, in a 64-bit integer (a decimal string in JSON).
  • UUIDs are hyphenated strings in the form xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.
  • Amounts are decimal strings in the unit stated by the field (for example wei, satoshi or lamports), never floating-point numbers. A request created through the API holds an integer in that unit. For a request created in the MPCVault app, the stored amount is returned scaled to that unit without rounding, so it can have a fractional part if more precision was entered than the unit has. The stored amount can differ from the amount entered (for example, a Bitcoin send is capped to the value of the first 30 spendable outputs less a reserve for the fee).
  • Addresses use the address format of the field’s network. The signing request payloads state the format of each address field.
  • Hex strings are stated as such in the field description, with or without the 0x prefix as that field specifies.