> ## Documentation Index
> Fetch the complete documentation index at: https://docs.presschain.io/llms.txt
> Use this file to discover all available pages before exploring further.

# RPC Endpoints

> All PressChain RPC endpoints, supported JSON-RPC methods, WebSocket subscriptions, and rate limits.

## Endpoint Reference

| Endpoint                            | Type             | Use Case                                |
| ----------------------------------- | ---------------- | --------------------------------------- |
| `https://rpc.presschain.io`         | JSON-RPC HTTP    | Standard EVM queries, tx submission     |
| `https://testnet-rpc.presschain.io` | JSON-RPC HTTP    | Testnet-specific queries                |
| `https://archive.rpc.presschain.io` | Archive JSON-RPC | Historical state queries, all blocks    |
| `wss://ws.presschain.io`            | WebSocket        | Real-time block and event subscriptions |

Internal (server-side only - never expose publicly):

<div className="pc-data-grid">
  <div className="pc-data-item"><span className="pc-data-label">Mainnet HTTP</span><span className="pc-data-val">127.0.0.1:8545</span></div>
  <div className="pc-data-item"><span className="pc-data-label">Mainnet WS</span><span className="pc-data-val">127.0.0.1:8546</span></div>
  <div className="pc-data-item"><span className="pc-data-label">Testnet HTTP</span><span className="pc-data-val">127.0.0.1:9545</span></div>
  <div className="pc-data-item"><span className="pc-data-label">Testnet WS</span><span className="pc-data-val">127.0.0.1:9546</span></div>
</div>

***

## Supported JSON-RPC Methods

### Chain State

```bash theme={null}
# Current block number
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'
# → {"jsonrpc":"2.0","id":1,"result":"0x100123"}

# Chain ID
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'
# → {"result":"0x499b4da"}  (77117002 decimal)

# Peer count
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":1}'

# Gas price
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_gasPrice","params":[],"id":1}'
```

### Accounts & Balances

```bash theme={null}
# PRESS balance for an address
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getBalance",
    "params": ["0xYOUR_ADDRESS", "latest"],
    "id": 1
  }'

# Transaction count (nonce)
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionCount",
    "params": ["0xYOUR_ADDRESS", "latest"],
    "id": 1
  }'
```

### Contract Calls

```bash theme={null}
# eth_call - read a view function
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_call",
    "params": [{
      "to": "0x4b39edF3fA0e7DBAFFA45FDCBbE08B6681D1076b",
      "data": "0x..."
    }, "latest"],
    "id": 1
  }'

# Estimate gas
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_estimateGas",
    "params": [{"to": "0x...", "data": "0x..."}],
    "id": 1
  }'
```

### Transactions

```bash theme={null}
# Submit a signed transaction
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_sendRawTransaction",
    "params": ["0xSIGNED_TX_HEX"],
    "id": 1
  }'

# Get transaction by hash
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionByHash",
    "params": ["0xTX_HASH"],
    "id": 1
  }'

# Get transaction receipt (after mining)
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionReceipt",
    "params": ["0xTX_HASH"],
    "id": 1
  }'
```

### Event Logs

```bash theme={null}
# Get logs - filter by contract and event topic
curl https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getLogs",
    "params": [{
      "fromBlock": "0x0",
      "toBlock": "latest",
      "address": "0x121885Cd339BF495cbC63e0f49e16c7CB2A1C62a",
      "topics": ["0xCAPSULE_ACCEPTED_TOPIC_HASH"]
    }],
    "id": 1
  }'
```

***

## ethers.js v6

```typescript theme={null}
import { JsonRpcProvider, WebSocketProvider, Contract, formatUnits } from "ethers";

// HTTP provider
const provider = new JsonRpcProvider("https://rpc.presschain.io");

// Archive provider - for historical state
const archive = new JsonRpcProvider("https://archive.rpc.presschain.io");

// WebSocket provider - real-time events
const ws = new WebSocketProvider("wss://ws.presschain.io");

// Basic queries
const block   = await provider.getBlockNumber();
const balance = await provider.getBalance("0xADDRESS");
const network = await provider.getNetwork();

console.log("Chain ID:", network.chainId.toString()); // "77117002"
console.log("Block:   ", block);
console.log("Balance: ", formatUnits(balance, 18), "PRESS");
```

***

## WebSocket Subscriptions

```typescript theme={null}
const ws = new WebSocketProvider("wss://ws.presschain.io");

// Subscribe to new blocks
ws.on("block", (blockNumber: number) => {
  console.log("New block:", blockNumber);
});

// Subscribe to ArticleRegistry events
import ArticleRegistryABI from "./abis/ArticleRegistry.json";

const registry = new Contract(
  "0x121885Cd339BF495cbC63e0f49e16c7CB2A1C62a",
  ArticleRegistryABI,
  ws
);

// Watch for capsule submissions
registry.on("CapsuleSubmitted", (capsuleId, outletSlug, submitter, event) => {
  console.log(`New capsule #${capsuleId} from ${outletSlug}`);
});

// Watch for capsule acceptance
registry.on("CapsuleAccepted", (capsuleId, outletSlug, acceptedAt, event) => {
  console.log(`Capsule #${capsuleId} accepted at block ${event.blockNumber}`);
});

// Watch for votes cast
const acceptance = new Contract(
  "0x63D0c0b51a3856a539b36a909517a18BddDb4a32",
  CapsuleAcceptanceABI,
  ws
);

acceptance.on("VoteCast", (capsuleId, voter, support, weight, event) => {
  console.log(`Vote on #${capsuleId}: ${support ? "YES" : "NO"} (weight: ${weight})`);
});
```

***

## Archive Node - Historical Queries

Use `archive.rpc.presschain.io` for any query needing state at a specific past block:

```typescript theme={null}
// Get balance at a specific block
const historicalBalance = await archive.getBalance(
  "0xADDRESS",
  1_000_000   // block number
);

// Get contract state at a past block
const pastCapsuleCount = await registry.capsuleCount({ blockTag: 500_000 });

// Full log history from genesis
const allAcceptances = await archive.getLogs({
  address: "0x121885Cd339BF495cbC63e0f49e16c7CB2A1C62a",
  fromBlock: 0,
  toBlock: "latest",
  topics: [registry.interface.getEvent("CapsuleAccepted")!.topicHash]
});
```

***

## Rate Limits

| Endpoint                 | Limit              | Notes            |
| ------------------------ | ------------------ | ---------------- |
| Public HTTP RPC          | 100 req/min per IP | Standard reads   |
| `eth_sendRawTransaction` | 20 req/min per IP  | Write protection |
| Archive RPC              | 20 req/min per IP  | Heavy queries    |
| WebSocket subscriptions  | 10 per connection  |                  |

For high-throughput integrations (indexers, data pipelines), contact PressLabs about dedicated RPC access.

***

## Health Check

```bash theme={null}
#!/bin/bash
# Quick RPC health check
RESULT=$(curl -s https://rpc.presschain.io \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}')

BLOCK=$(echo $RESULT | python3 -c "
import sys, json
r = json.load(sys.stdin)
print(int(r.get('result','0x0'), 16))
" 2>/dev/null)

echo "RPC Status: $([ -n "$BLOCK" ] && echo "OK" || echo "FAIL")"
echo "Block: ${BLOCK:-N/A}"
```

***

## Error Codes

| Code     | Meaning                                          |
| -------- | ------------------------------------------------ |
| `-32700` | Parse error - invalid JSON                       |
| `-32600` | Invalid request                                  |
| `-32601` | Method not found                                 |
| `-32602` | Invalid params                                   |
| `-32603` | Internal error                                   |
| `-32000` | Server error (gas too low, nonce mismatch, etc.) |