Chrysalis Migration

With the advent of the Chrysalis migration, a number of aspects at IOTA are changing for the better. With easier ways to manage and secure your experience, IOTA will seamlessly integrate these innovations with no service interruptions.

With Chrysalis, we make a clear-cut from the current IOTA protocol, and start a new with a much better, and more mature network. The new network will support many new use cases and create a foundation for IOTA’s upcoming Coordicide.

This includes one of the innovations that directly impacts one of the most crucial aspects of your experience: funds.

Because of its complexity, the migration process for the next phase of Chrysalis consists of two phases; we are currently in phase one where you initiate the migration of your funds in one week and which will then be available on our new network upon launch.

Do note that migrating is a continuous effort that can be done at any time after the initial migration start date.

Token Migration Overview

Below is an overview of how the migration will take place for normal token holders:

  • You enter your seed in Firefly.
  • Firefly creates you a new seed and generates an EdDSA address for the new network.
  • Firefly sends your funds to a specific migration address (which encapsulates your EdDSA address) on the old network.
  • Your funds become available on the new network on the EdDSA address Firefly created for you.
  • Your funds are successfully migrated.

Note that:

  • If you migrate before the Chrysalis launch, your funds become available at Chrysalis launch.
  • If you migrate after the Chrysalis launch, your funds will become available shortly after you migrate (within less than 5 minutes).

Firefly will initially only be available on desktop operating systems such as: macOS, Linux and Windows and not support migrations for Ledger devices or using a Ledger device.

For further information on the migration process, see our blog post.

For a detailed explainer on how the migration process works technically, see migration-mechanism

Exchange Token Migration Guide

To help you successfully transfer your tokens securely to the new Chrysalis (IOTA 1.5) network, we created this guide as an overview of the migration process and its intricacies.

Following dates are important to be aware of:

  • From 21st to 28th of April, token holders are able to pre-migrate their funds. During this period the network has no limitations and runs as it would normally. Migrating funds during this period effectively locks them up to become available immediately on the 28th of April after the Chrysalis Phase 2 release.
  • On the 28th of April, Chrysalis Phase 2 gets released (with its corresponding node software, libraries and tooling). After that, the legacy network will only support migration transfers going further (this is accompanied by a legacy node release). This means that both a legacy (albeit only for migrations), and a new Chrysalis Phase 2 network will co-exist. We therefore suggest stopping withdrawals and deposits some time before the 28th of April, to ensure that no funds are being sent from/to the exchange (since any non migration transfers will no longer confirm).

There are two ways with which you can migrate your funds from the old legacy to new Chrysalis Phase 2 network:

  1. You can either use our Firefly wallet (which allows migrating from either an 81-tryte seed or seed vault file). (Check out this blog post on how to do this).
  2. Or you can craft a migration bundle yourself which transfers your funds to a special migration address under your control (programmatic approach).

Note that if you migrate your funds after the 28th of April, they will become available on the new network within 5 minutes. If you migrate prior to that, your funds will only become available starting on the 28th of April.

This guide will further only explain how to create a migration bundle, and the rules imposed on it.

Migrating funds by issuing migration bundles

Note that as mentioned above, there will be a special release for the legacy node software on the 28th of April, which will only further support migration bundles. In case you're operating a node yourself you must upgrade to that version, as otherwise you will no longer be synchronized with the network.

Migration bundle

With this limited legacy network, only migration bundles will further confirm. A migration bundle is nothing else than a normal value bundle/transfer which has some additional restrictions. If you craft a bundle which obeys to the following rules, then it falls under what we define as a migration bundle:

  • It contains exactly one output transaction of which the destination address is a valid migration address and is positioned as the tail transaction within the bundle (meaning currentIndex 0). The output transaction value is at least 1'000'000 tokens (1 Mi).
  • It does not contain any zero-value transactions which do not hold signature fragments. This means that transactions other than the tail transaction must always be part of an input.
  • Input transactions must not use migration addresses.

If in doubt whether your bundle is an actual migration bundle, you can use ValidBundle(bundle, true) function of our iota.go library to validate this. In case you're not acquainted with Go, you can also contact us on Discord or Slack in order to get the assurance, that you're crafted bundles are valid migration bundles.

Things to consider:

  • You must not broadcast your own migration bundles unless you're 100% sure that they are indeed valid migration bundles.
  • If one of your input transactions spends funds from an already used address (meaning it is subject to key re-use), we recommend that you use the bundle miner tool to craft a bundle with the most applicable security given the already exposed parts of the given address' private key.
  • Do not use too many input transactions as this will increase the overall Proof-of-Work time needed for a single bundle. Rather, split your input addresses over multiple migration bundles.
  • Your code must include logic to await for the migration bundle's confirmation. If you find that your migration bundle is not confirming, consider re-attaching it (re-attaching is not the same as re-signing the bundle!).
  • If you submit a migration bundle for broadcasting via the broadcastTransactions API command and you're using the updated legacy node software (which you must on/after the 28th of April), then it will additionally check up on submission whether your submitted bundle really adheres to the rules outlined above as an additional safe guard.

For further information about the migration bundles, have a look at RFC-0035 .

As an example, this bundle is a valid migration bundle. It spends 1 Mi

  • to: TRANSFERTBIXPEWWYZZWBWPWJCB9XYMC9AGYH9X9AYAYADVXTYGYB9G9J9PEF9O9KYZXS9D9MANWTZOD9B9HMRQFWZ where the destination address encodes the target Bech32 address iota1qqhmslysuwfedz2mqtr4ux73pr7uhjmd4tpazqs8pf7qdax44muqgw0fz25 respectively the hex Ed25519 address 2fb87c90e39396895b02c75e1bd108fdcbcb6daac3d102070a7c06f4d5aef804 on which the these funds will be made available in the new network.
Migration Address

As mentioned above, a migration bundle must have as its single destination/output address a migration address. A migration address is in essence an EdDSA address (to which you hold the keys on the new network) encoded in a legacy tryte address. You can create such an address in the following way:

  • Compute the BLAKE2b-256 hash H of your Ed25519 address A (this address is the one you control in the new network; note that an Ed25519 address is the Blake2b-256 hash of your Ed25519 public key).
  • Append the first 4 bytes of H to A, resulting in 36 bytes.
  • Convert A to trytes using the b1t6 encoding (as described in RFC-15) . This results in Atri consisting of 72 trytes.
  • Prepend the 8-tryte prefix TRANSFER to Atri.
  • Finally, pad Atri with the single tryte 9 to get a legacy 81-tryte address.


  • Ed25519 address (32-byte): 6f9e8510b88b0ea4fbc684df90ba310540370a0403067b22cef4971fec3e8bb8

Since nobody holds keys to such migration addresses, funds are effectively burned and can no longer be used in the legacy network.