debug_traceBlock

debug_traceBlock takes a Polygon PoS block as raw RLP bytes, re-executes it against its parent state, and returns a trace for each transaction. It is the byte-input sibling of debug_traceBlockByHash: instead of naming a block already on-chain, you hand the node the encoded block itself. Polygon's Bor client is Geth-based, so the usual callTracer, prestateTracer, and default struct-log tracers apply to these MATIC-fee blocks. Send the request to https://polygon.therpc.io/YOUR_API_KEY (chain ID 137, 0x89). It returns opcode-level execution traces for every transaction in the block provided as RLP-encoded bytes.

Use cases

• Trace a custom or modified Polygon block that is not yet on-chain, such as one assembled in a Bor simulation or test environment.
• Reproduce block execution when you already hold the RLP bytes — for example from a Bor p2p capture or a locally re-encoded block.

Parameters

Response

Example request

1curl https://polygon.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "debug_traceBlock",
7    "params": [
8        "0xf9...",
9        {}
10      ],
11    "id": 1
12  }'

Try it live in the Polygon playground.

Errors & troubleshooting

Common pitfalls

• Producing a correctly RLP-encoded Polygon block is fiddly: most callers fetch it via eth_getBlockByHash with full transactions and then re-encode, since a single malformed field rejects the whole input.
• The node needs the parent state to replay the block, so historical blocks require a Bor archive node — Polygon's fast block production prunes that state from full nodes quickly.
• Performance matches debug_traceBlockByHash: it is a full block replay, so cost scales with how many transactions the block carries, not with the convenience of passing raw bytes.

Supported networks

• Mainnet — Chain ID: 137
• Amoy — Chain ID: 80002

See also

• debug_traceBlockByNumber
• debug_traceBlockByHash
• debug_traceTransaction

1curl https://polygon.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"debug_traceBlock","params":["",{}]}'