diff --git a/jsonerr.go b/jsonerr.go
new file mode 100644
index 00000000..4b8935c7
--- /dev/null
+++ b/jsonerr.go
@@ -0,0 +1,147 @@
+// Copyright (c) 2013 Conformal Systems LLC.
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcjson
+
+// Standard JSON-RPC 2.0 errors
+var (
+	ErrInvalidRequest = Error{
+		Code:    -32600,
+		Message: "Invalid request",
+	}
+	ErrMethodNotFound = Error{
+		Code:    -32601,
+		Message: "Method not found",
+	}
+	ErrInvalidParams = Error{
+		Code:    -32602,
+		Message: "Invalid paramaters",
+	}
+	ErrInternal = Error{
+		Code:    -32603,
+		Message: "Internal error",
+	}
+	ErrParse = Error{
+		Code:    -32700,
+		Message: "Parse error",
+	}
+)
+
+// General application defined JSON errors
+var (
+	ErrMisc = Error{
+		Code:    -1,
+		Message: "Miscellaneous error",
+	}
+	ErrForbiddenBySafeMode = Error{
+		Code:    -2,
+		Message: "Server is in safe mode, and command is not allowed in safe mode",
+	}
+	ErrType = Error{
+		Code:    -3,
+		Message: "Unexpected type was passed as parameter",
+	}
+	ErrInvalidAddressOrKey = Error{
+		Code:    -5,
+		Message: "Invalid address or key",
+	}
+	ErrOutOfMemory = Error{
+		Code:    -7,
+		Message: "Ran out of memory during operation",
+	}
+	ErrInvalidParameter = Error{
+		Code:    -8,
+		Message: "Invalid, missing or duplicate parameter",
+	}
+	ErrDatabase = Error{
+		Code:    -20,
+		Message: "Database error",
+	}
+	ErrDeserialization = Error{
+		Code:    -22,
+		Message: "Error parsing or validating structure in raw format",
+	}
+)
+
+// Wallet JSON errors
+var (
+	ErrWallet = Error{
+		Code:    -4,
+		Message: "Unspecified problem with wallet",
+	}
+	ErrWalletInsufficientFunds = Error{
+		Code:    -6,
+		Message: "Not enough funds in wallet or account",
+	}
+	ErrWalletInvalidAccountName = Error{
+		Code:    -11,
+		Message: "Invalid account name",
+	}
+	ErrWalletKeypoolRanOut = Error{
+		Code:    -12,
+		Message: "Keypool ran out, call keypoolrefill first",
+	}
+	ErrWalletUnlockNeeded = Error{
+		Code:    -13,
+		Message: "Enter the wallet passphrase with walletpassphrase first",
+	}
+	ErrWalletPassphraseIncorrect = Error{
+		Code:    -14,
+		Message: "The wallet passphrase entered was incorrect",
+	}
+	ErrWalletWrongEncState = Error{
+		Code:    -15,
+		Message: "Command given in wrong wallet encryption state",
+	}
+	ErrWalletEncryptionFailed = Error{
+		Code:    -16,
+		Message: "Failed to encrypt the wallet",
+	}
+	ErrWalletAlreadyUnlocked = Error{
+		Code:    -17,
+		Message: "Wallet is already unlocked",
+	}
+)
+
+// Specific Errors related to commands.  These are the ones a user of the rpc
+// server are most likely to see.  Generally, the codes should match one of the
+// more general errors above.
+var (
+	ErrBlockNotFound = Error{
+		Code:    -5,
+		Message: "Block not found",
+	}
+	ErrBlockCount = Error{
+		Code:    -5,
+		Message: "Error getting block count",
+	}
+	ErrBestBlockHash = Error{
+		Code:    -5,
+		Message: "Error getting best block hash",
+	}
+	ErrDifficulty = Error{
+		Code:    -5,
+		Message: "Error getting difficulty",
+	}
+	ErrOutOfRange = Error{
+		Code:    -1,
+		Message: "Block number out of range",
+	}
+	ErrNoTxInfo = Error{
+		Code:    -5,
+		Message: "No information available about transaction",
+	}
+	ErrNoNewestBlockInfo = Error{
+		Code:    -5,
+		Message: "No information about newest block",
+	}
+	ErrRawTxString = Error{
+		Code:    -32602,
+		Message: "Raw tx is not a string",
+	}
+	ErrDecodeHexString = Error{
+		Code:    -22,
+		Message: "Unable to decode hex string",
+	}
+)