rpc_methods | Hydration RPC Docs

List all available RPC methods on Hydration. Essential for API discovery, capability detection, and building dynamic tooling for Substrate-based chains.

Returns a list of all RPC methods exposed by the Hydration node. This is the definitive way to discover what methods are available on a given endpoint, including both standard Substrate methods and any custom chain-specific extensions.

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When to Use This Method

rpc_methods is essential for DeFi developers, liquidity providers, and DAOs requiring capital-efficient trading:

API Discovery -- Enumerate all available RPC methods to understand the full capabilities of a Hydration node
Capability Detection -- Check whether a specific method (e.g., author_submitExtrinsic, state_call) is available before calling it
Compatibility Testing -- Verify that an endpoint supports the methods your application requires for single-sided liquidity provision, cross-chain trading (SOL, KSM, tBTC), and HOLLAR decentralized stablecoin
Tooling and Documentation -- Auto-generate API references or client SDKs from the available method list

async function validateEndpoint(endpoint, requiredMethods) {
  const response = await fetch(endpoint, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      jsonrpc: '2.0',
      method: 'rpc_methods',
      params: [],
      id: 1
    })
  });

  const { result } = await response.json();
  const available = new Set(result.methods);

  const missing = requiredMethods.filter((m) => !available.has(m));

  if (missing.length > 0) {
    console.error('Missing required methods:', missing);
    return false;
  }

  console.log('Endpoint supports all required methods');
  return true;
}

// Usage
await validateEndpoint('https://api-hydradx.dwellir.com/YOUR_API_KEY', [
  'state_getStorage',
  'state_call',
  'author_submitExtrinsic',
  'payment_queryInfo'
]);

2. Method Category Breakdown

Organize available methods by their RPC namespace:

JavaScript

async function getMethodsByCategory(api) {
  const methods = await api.rpc.rpc.methods();
  const categories = {};

  methods.methods.forEach((method) => {
    const name = method.toString();
    const category = name.split('_')[0];
    categories[category] = categories[category] || [];
    categories[category].push(name);
  });

  for (const [category, methodList] of Object.entries(categories)) {
    console.log(`\n${category} (${methodList.length} methods):`);
    methodList.forEach((m) => console.log(`  - ${m}`));
  }

  return categories;
}

3. Compare Endpoints

Detect differences between two Hydration endpoints:

JavaScript

async function compareEndpoints(endpoint1, endpoint2) {
  const fetchMethods = async (url) => {
    const res = await fetch(url, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ jsonrpc: '2.0', method: 'rpc_methods', params: [], id: 1 })
    });
    const { result } = await res.json();
    return new Set(result.methods);
  };

  const [methods1, methods2] = await Promise.all([
    fetchMethods(endpoint1),
    fetchMethods(endpoint2)
  ]);

  const onlyIn1 = [...methods1].filter((m) => !methods2.has(m));
  const onlyIn2 = [...methods2].filter((m) => !methods1.has(m));

  if (onlyIn1.length) console.log('Only in endpoint 1:', onlyIn1);
  if (onlyIn2.length) console.log('Only in endpoint 2:', onlyIn2);
  if (!onlyIn1.length && !onlyIn2.length) console.log('Endpoints have identical methods');
}

Error Handling

Common errors and solutions:

Error Code	Description	Solution
-32603	Internal error	Node may be starting up -- retry after delay
HTTP 429 / -32029	Rate limit exceeded	Cache the method list since it rarely changes at runtime and back off before retrying
Connection refused	Node unreachable	Verify the RPC endpoint URL and that the node is running

system_chain -- Get the chain name
system_name -- Get the node implementation name
system_version -- Get the node implementation version
state_getMetadata -- Get full runtime metadata including pallet and call definitions

rpc_methods - Hydration RPC Method

When to Use This Method

Code Examples

Common Use Cases

1. Endpoint Capability Validation

2. Method Category Breakdown

3. Compare Endpoints

Error Handling

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