diff --git a/docs.json b/docs.json
index 8306c1d2f..8c937ea9b 100644
--- a/docs.json
+++ b/docs.json
@@ -73,6 +73,7 @@
                 "expanded": true,
                 "pages": [
                   "ecosystem/api/toncenter/get-api-key",
+                  "ecosystem/api/toncenter/v3-errors",
                   {
                     "group": "API v2",
                     "openapi": {
diff --git a/ecosystem/api/toncenter/v3-errors.mdx b/ecosystem/api/toncenter/v3-errors.mdx
new file mode 100644
index 000000000..be76bf26d
--- /dev/null
+++ b/ecosystem/api/toncenter/v3-errors.mdx
@@ -0,0 +1,133 @@
+---
+title: "API v3 error codes"
+---
+
+## Overview
+
+| Status | Meaning                        |
+| ------ | ------------------------------ |
+| `401`  | Missing required field         |
+| `404`  | Data not found                 |
+| `409`  | Resource exists but wrong type |
+| `422`  | Invalid request parameters     |
+| `500`  | Server-side failure            |
+
+## By task
+
+### Account & wallet info
+
+**Endpoints:** `/api/v3/account`, `/api/v3/addressInformation`, `/api/v3/wallet`, `/api/v3/walletInformation`, `/api/v3/accountStates`, `/api/v3/walletStates`
+
+| Status | Error                            | Fix                                             |
+| ------ | -------------------------------- | ----------------------------------------------- |
+| `401`  | `address of account is required` | Include the `address` parameter                 |
+| `409`  | `not a wallet`                   | Account exists but isn't a wallet contract      |
+| `500`  | `balance is none`                | Indexer couldn't read balance from stored state |
+| `500`  | `status is none`                 | Indexer couldn't resolve account status         |
+| `500`  | `last_transaction_hash is none`  | No last transaction hash in indexed data        |
+| `500`  | `last_transaction_lt is none`    | No last transaction lt in indexed data          |
+
+### Sending messages
+
+**Endpoint:** `/api/v3/message`
+
+| Status | Error             | Fix                                          |
+| ------ | ----------------- | -------------------------------------------- |
+| `401`  | `boc is required` | Include a serialized BoC in the request body |
+
+### Running get methods
+
+**Endpoint:** `/api/v3/runGetMethod`
+
+| Status | Error                 | Fix                             |
+| ------ | --------------------- | ------------------------------- |
+| `401`  | `address is required` | Include target contract address |
+| `401`  | `method is required`  | Include the get-method name     |
+
+### Querying blocks & shards
+
+**Endpoints:** `/api/v3/masterchainBlockShardState`, `/api/v3/masterchainBlockShards`
+
+| Status | Error              | Meaning                                 |
+| ------ | ------------------ | --------------------------------------- |
+| `404`  | `blocks not found` | Block or shard doesn't exist in storage |
+
+### Transactions & messages
+
+**Endpoint:** `/api/v3/transactionsByMessage`
+
+| Status | Error                                                             | Fix                         |
+| ------ | ----------------------------------------------------------------- | --------------------------- |
+| `422`  | `at least one of msg_hash, body_hash, opcode should be specified` | Provide at least one filter |
+
+### Pending transactions & traces
+
+**Endpoints:** `/api/v3/pendingTransactions`, `/api/v3/pendingTraces`, `/api/v3/pendingActions`
+
+| Status | Error                                               | Fix                                        |
+| ------ | --------------------------------------------------- | ------------------------------------------ |
+| `422`  | `at least 1 account address required`               | Include at least one account address       |
+| `422`  | `only one of account, trace_id should be specified` | Use only one filter                        |
+| `422`  | `account or ext_msg_hash should be specified`       | Filter by account or external message hash |
+| `500`  | `emulatedTracesRepository is not initialized`       | Server-side issue                          |
+
+### Traces & events
+
+**Endpoints:** `/api/v3/traces`, `/api/v3/events`
+
+| Status | Error                                                                  | Fix                         |
+| ------ | ---------------------------------------------------------------------- | --------------------------- |
+| `422`  | `only one of account, trace_id, tx_hash, msg_hash should be specified` | Use only one primary filter |
+
+### Address book & metadata
+
+**Endpoints:** `/api/v3/addressBook`, `/api/v3/metadata`
+
+| Status | Error                         | Fix                                   |
+| ------ | ----------------------------- | ------------------------------------- |
+| `422`  | `at least 1 address required` | Include a non-empty list of addresses |
+
+### DNS records
+
+**Endpoint:** `/api/v3/dns/records`
+
+| Status | Error                                               | Fix                              |
+| ------ | --------------------------------------------------- | -------------------------------- |
+| `422`  | `either wallet address or domain is required`       | Provide wallet address or domain |
+| `422`  | `provide either wallet address or domain, not both` | Use one filter, not both         |
+
+### NFT items
+
+**Endpoint:** `/api/v3/nft/items`
+
+| Status | Error                                                              | Fix                                                           |
+| ------ | ------------------------------------------------------------------ | ------------------------------------------------------------- |
+| `422`  | `exact one owner_address required for multiple collection_address` | When querying multiple collections, provide exactly one owner |
+
+### Jetton wallets
+
+**Endpoint:** `/api/v3/jetton/wallets`
+
+| Status | Error                                                          | Fix                                                              |
+| ------ | -------------------------------------------------------------- | ---------------------------------------------------------------- |
+| `422`  | `exact one owner_address required for multiple jetton_address` | When querying multiple jetton masters, provide exactly one owner |
+
+### Multisig
+
+**Endpoints:** `/api/v3/multisig/wallets`, `/api/v3/multisig/orders`
+
+| Status | Error                                                             | Fix                                          |
+| ------ | ----------------------------------------------------------------- | -------------------------------------------- |
+| `422`  | `At least one of address or wallet_address should be specified`   | Filter by multisig contract or signer wallet |
+| `422`  | `At least one of address or multisig_address should be specified` | Filter by order address or parent multisig   |
+
+### Decoding
+
+**Endpoint:** `/api/v3/decode`
+
+| Status | Error                                         | Fix                                                              |
+| ------ | --------------------------------------------- | ---------------------------------------------------------------- |
+| `422`  | `opcodes list exceeds maximum length of 1000` | Reduce number of opcodes                                         |
+| `422`  | `bodies list exceeds maximum length of 1000`  | Reduce number of message bodies                                  |
+| `422`  | `invalid opcode format at index %d: %s`       | Fix the opcode at specified index (must be valid hex or decimal) |
+| `500`  | `marker request failed: <details>`            | Internal decode service failed                                   |