RPC client

mero.rpc (RpcClient) calls the methods a context’s WASM application exposes, over the node’s /jsonrpc endpoint. It shares the SDK’s transport, so authentication, refresh, and the error model apply. A contract-level failure surfaces as MeroError.rpc(RpcError).

See the executing methods guide for task-oriented examples.

execute<T: Decodable>(...)

func execute<T: Decodable>(
    contextId: String,
    method: String,
    argsJson: [String: JSONValue] = [:]
) async throws -> T

Calls method on the application in contextId and decodes result.output into T. argsJson is a [String: JSONValue] map (JSONValue is ExpressibleBy…Literal, so ["id": "42", "n": 3] works). A JSON-RPC error object is mapped to MeroError.rpc(RpcError).

struct Post: Decodable { let id: String; let title: String }

let post: Post = try await mero.rpc.execute(
    contextId: contextId,
    method: "get_post",
    argsJson: ["id": "42"]
)

Note

There is no executorPublicKey. Core’s execute request accepts only contextId, method and argsJson and refuses any other field, so the identity a call runs as is the one the token is bound to.

migrateMyEntries(_ contextId:) -> MigrateMyEntriesSummary

Owner-driven migration: re-signs the caller’s identity-gated entries to the current schema in a single sweep (it does not loop). Returns the counts.

public struct MigrateMyEntriesSummary: Codable, Sendable, Equatable {
    public let converted: Int   // entries re-signed this call
    public let remaining: Int   // still below the target schema
}

let summary = try await mero.rpc.migrateMyEntries(contextId)

executeWithMetadata<T>(...) -> RpcExecuteResult<T>

The same call as execute, returning { returns, transport } with transport always .node. It mirrors mero-js’s transport-agnostic shape.

let result: RpcExecuteResult<Int> = try await mero.rpc.executeWithMetadata(
    contextId: contextId, method: "get")

Refusals since core rc.83

• An execute needs context:execute in a scoped token (or admin).
• An account-authenticated session cannot execute; it writes through a warranted intent (mero.admin.performIntent).
• A node whose role in the context is read-only answers {"type":"ReadOnlyWriteRefused","data":{"context_id":...}}. Check rpcError.isReadOnlyWriteRefused and send the write elsewhere.

countMyPending(_ contextId:) -> Int

Read-only count of the caller’s entries still below the target schema — decide whether to migrate, or show progress.

let pending = try await mero.rpc.countMyPending(contextId)
if pending > 0 { _ = try await mero.rpc.migrateMyEntries(contextId) }