Welcome to the Tezos alphanet, which is a pre-release network for the Tezos blockchain. Currently, the chain is reset every few weeks.

For news and support about the alphanet, please join IRC (#tezos on freenode). Please, report bugs related to the alphanet on the IRC channel before filling GitLab issues.

For more information about the project in general, see:

How to join the alphanet

We provide two ways of joining the alphanet :

  • an installation script that uses docker and prebuilt binaries (recommended way, tested on windows/mac/linux, works on x86_64 architecture only),
  • manual compilation and installation (linux and mac only).

The script (x86_64 only)

The recommended way for running an up-to-date Tezos node connected to the alphanet is to use scripts/ Its only requirement is a working installation of Docker.

First, you need to download the script:

chmod +x

You are now one step away from a working node:

./ start

This will launch a docker container running the various daemons that form a working tezos node. The first launch might take a few minutes to synchronize the chain.

See ./ --help for more informations about the script. In particular see ./ client --help and scripts/README.master for more information about the client.

Every call to will check for updates of the node and will fail if your node is not up-to-date. For updating the node, simply run:

./ restart

If you prefer to temporarily disable automatic updates, you just have to set an environment variable:


Compilation from sources

Please refer to the instructions.

For the rest of the document, to execute the example commands, you will have to replace ./ client by ./tezos-client.

How to observe the network

The alphanet script provides a basic command ./ head that allows you to see if your own node is synchronized.

The Tezos client also offers a lot of commands to introspect the state of the node, and also to list and call the RPCs of the nodes.

Enthusiastic Tezos adopters have also developed some block explorer for the alphanet. See for instance:

How to obtain free Tezzies

You must first grab a wallet from the faucet.

This will provide you with a JSON file, named like tz1__xxxxxxxxx__.json. Once your node is synchronized, you should run the following command to activate your wallet, where my_account is a local name you choose, and tz1__xxxxxxxxx__.json is the name of the file you grab:

$ tezos-client activate account "my_account" with "tz1__xxxxxxxxx__.json"
Operation successfully injected in the node.
Operation hash is 'ooGoVS5cikbTHEimTzYhQWrYqY2LeJYmfkbzoiW8KQ59jtGQaXr'.
Waiting for the operation to be included...
Operation found in block: BKihN2QgSAu2etftNvs8FWWhwTvZiY8P3e7H3jgdj2MCpKZXXRs
Account my_account (tz1__xxxxxxxxx__) created with ꜩ23,454.

Or, if you use the script, you should prefix the file with container: in order to copy it into the docker image:

$ ./ client activate account "my_account" with "container:tz1__xxxxxxxxx__.json"

You might check your balance with:

./ client get balance for "my_account"

Please preserve the JSON file, after each reset of the Alphanet, you will have to reactivate the wallet. The same file might be use ta activate an account on the Zeronet.

Please drink carefully and don’t abuse the faucet: it only contains 30.000 wallets for a total amount of ꜩ760.000.000.

How to play with smart-contracts

An advanced documentation of the smart contract language is available here.

Some test contracts can be found in directory src/bin_client/test/contracts/.

For details and examples, see also

How to bake on the alphanet

Baking 101

In order to understand how baking works, please refer to this section. The following is a TL;DR to help you get started.

In Tezos there are two kinds of contracts: implicit and originated accounts. Originated accounts can have michelson code, in which case they are also called contracts.

  • An implicit account is identified by a public key hash and is automatically created when a public key hash is the recipient of a transfer. The genesis block will contain one account per contributor.
  • An originated account or contract is originated with an operation sent to the blockchain. It has a manager and an optional delegate account.

The baking itself is done by implicit accounts. By default, they don’t participate in baking unless they are registred as delegates. In order to register an implicit account as a delegate, use:

./ client register key "my_account" as delegate

Once registered, an implicit account can participate in baking for its own balance plus the balance of originated accounts and contracts that are delegated to it.

Originated accounts and contracts thus participate in baking only via their delegate. If they don’t have a delegate set (the default, unless you specify one), they don’t participate in baking.

Implicit accounts cannot have a delegate. In order to delegate funds, they need to be transfered to an originated account beforehand, and a delegate must be set.

To summarize:

  • Implicit accounts only can be registered as delegates and actually bake.
  • Funds in implicit accounts which are not registered as delegates do not participate in baking.
  • Originated accounts and contracts do not participate in baking unless they have a delegate account set and this delegate is actually baking.

In order to be entitled to bake, delegates need enough tezzies (delegated or otherwise) to have a least one roll. Baking rights are randomly chosen around rolls, which are blocks of 10K tezzies.

When you obtain Alphanet coins from the faucet, if you are lucky to obtain more than one roll, you can bake using this identity (after it is registered as a delegate). Otherwise, you need to ask the faucet for more coins. When you obtain more than 10K tezzies into one or multiple identities, you are ready to start baking!

Before we see how to bake with your delegate, you might want to know how to delegate your tezzies. Although not necessary (you can just bake with your delegate if it has enough tezzies), it is useful if you want for example to avoid transfering all your coins in one account.

Delegating your coins

As explained above, implicit accounts cannot have a delegate, so the first step is to originate an account and transfer your tezzies there. During the origination step, we will set the delegate.

./ client originate account <new> for <implicit> transfering <qty> from <implicit> --delegate <implicit>

Where <new> must be a contract alias that you choose, <implicit> is the alias of one implicit account that you own, and <qty> is the amount in tezzies that you want to transfer.

This will originate an account, transfer <qty> tezzies from <implicit> in it, and set that <implicit> is the manager and the delegate for this freshly minted account.

If you already own contracts that are delegatable and want to change the delegate to <implicit>, use the following command:

./ client set delegate for <account> to <implicit>

You need to wait at most seven cycles which, on the Alphanet, is 7*128 blocks (something about 15 hours). On the mainnet, this will be around 3 weeks.

From now on, the funds in <new> will be delegated to <implicit>. In the next section, we will learn how to bake with your delegate.

Baking with your delegate

If you have read and followed the doc up until this point, you now have a delegate, which have enough tezzies (delegated or otherwise) to bake.

When baking or endorsing a block, a security deposit (or bond) is taken out of the default account associated to the public key of the delegate. Hence, in order to bake, your delegate must have enough funds to be able to pay security deposits for baking and endorsing.

Check out the Alphanet constants for this:

./ client rpc get /blocks/head/proto/constants

Check for the endorsement_security_deposit and block_security_deposit keys of the JSON record. The value is in µtez, one millionth of a tezzie. In the alphanet, the current value is set to 512tz per block and 64tz per endorsement. If you run out of funds, you will not be able to bake.

Now, you are settled. The alphanet docker image runs a baker daemon and a endorser daemon, by default for all your keys.

To know if you baked, just run:

./ baker log
./ endorser log

You should see lines such as:

Injected block BLxzbB7PBW1axq for bootstrap5 after BLSrg4dXzL2aqq  (level 1381, slot 0, fitness 00::0000000000005441, operations 21)


Injected endorsement for block 'BLSrg4dXzL2aqq'  (level 1381, slot 3, contract bootstrap5) 'oo524wKiEWBoPD'

On the alphanet, rewards for staking are credited after 5 cycles (~10 hours). The reward for baking a block is ꜩ16 and ꜩ2 / <block_priority> for endorsing a block. The safety bond is returned together with the reward.

To know when you will be allowed to bake in the current cycle, you might try the following RPCs, where you replaced tz1iFY8ads... by the appropriate value:

$ ./ client list known addresses
my_account: tz1iFY8aDskx9QGbgBy68SNAGgkc7AE2iG9H (public key known) (secret key known)
$ ./ client rpc post /chains/main/blocks/head/helpers/rights/baking/delegate/tz1iFY8aDskx9QGbgBy68SNAGgkc7AE2iG9H with {}
{ "ok":
    [ { "level": 1400.000000, "priority": 2.000000,
        "timestamp": "2017-05-19T03:21:52Z" },
      ...  ] }


Reset 2018-05-03


  • New faucet :
  • secp256k1 as an alternative to ed25519
  • 32 endorsers per blocks (was 15)
  • Delegation rights are now frozen 5 cycles in advance (approx 15 days in mainnet or 10 hours on zeronet);
  • Security deposits are recovered after 5 cycles;
  • Rewards and fees are earned after 5 cycles;
  • Pending deposits and fees count in the staking balance of a delegate;
  • Delegates will be tagged as “deactivated” after 5 cycles of inactivity and they will lose their baking rights;
  • Do not allow revealing the same endorsement twice.
  • Tez values now have 6 decimals instead of two. The syntax used by the client and Michelson use comma separators every three digits, before and after the dot. For instance, 3 million tez and 10 µtez is written 3,000,000.000,01. The syntax in JSON is the raw amount in µtez, either as a number without decimals or as a decimal string, for the same example we would get “3000000000010”.


  • Rewrite of the RPC library to handle content types, to enable binary RPCs and proper HTTP verbs. The next version will probably break the HTTP API.
  • Now that we don’t use the git backend anymore, we finally updated the context hashing function from SHA1 to Blake2B.


  • Set a maximum type size, as a simple solution to avoid some type checker abuses where types can grow exponentially.
  • Annotations are now correctly handled by macros.


  • Split the code base into separate OPAM packages.

Patch 2018-01-15


  • Fix a performance issue in block locator computation

Reset 2017-11-20


  • Limit the number of faucet operations at 5 per block.


  • Autocomplete scripts for bash.
  • Smart contracts are now non spendable by default.
  • Add a debug command to list invalid blocks.


  • Prevent potential stack overflow in validation.
  • Fix concurrency issue where operations were cleared from
    memory before being used.
  • Continue background work on the multipass validator:
    cleanup and document data structures, better logging of resource requests, enhance requests for the same piece of data to multiple peers, split the code in smaller simpler components.
  • P2p: fix issue with data greater than 2^16 bytes
  • Irmin: use an experimental LMDB backend


  • Refactor the economic protocol amendment code. Protocols are
    now compiled to functors, taking the type signature of their runtime environment as parameter. This simplifies the dependencies, and will allow third party developers to instantiate economic protocols in other contexts than the node.
  • Switch from Makefiles to jbuilder, yay!
  • Rename (hopefully) all occurrences of “mining” into “baking”.


  • Introduce Micheline, the (now independent) IR of Michelson. The parser and printer should now be used on their own, outside of the client or node.
  • Implement a basic semantics of annotations.
    The typechecker now propagates annotations on types throughout the code, and tagging instructions with an annotation allows the programmer to reannotate the element produced by the instruction. The emacs mode displays propagated annotations.
  • Add a version of ITER that takes a static code block and expects
    a collection on the initial stack, and works like a LOOP, pushing the element of the collection one at a time on the stack. This is like REDUCE but using a static code block instead of a dynamic lambda. In the same vein, MAP can take a code block.
  • Add LOOP_LEFT that uses a different type for the accumulator and
    the return value. Continues while the top of the stack is Left ‘a and stops on Right ‘b.
  • Change timestamps to be arbitrary precision relative integers.
  • Add SIZE on lists.

Reset 2017-11-17


  • P2p: fix issue with data greater then 2^16 bytes
  • Irmin: restore usage git-repack... (mistakenly removed)

Reset 2017-10-13


  • Fix missing nonce revelation at end of cycle.
  • New command line analyzer and better help pages.


  • Various small fixes and error message enhancements.


  • Use older leveldb-1.18 as upgrade to the newer version made the node crash.


  • Split the key type into key and key_hash to prevent an error raised when using an unrevealed key.

Reset 2017-09-21


  • fix a performance issue in roll storage


  • improve scripts and documentations on how to run sandboxed node or a local private network


  • add an option -log-requests. All RPC requests and responses to the node are logged on stderr.


  • Split the key type into key and key_hash to prevent an error raised when using an unrevealed key.

Reset 2017-08-10

This update includes changes in the on-disk state of the node and in the format of blocks and operations. It thus requires a chain reset.

Main changes includes:



  • minor language enhancements, mostly resulting from the feedback of Milo’s daily challenge:

  • the alphanet scripts now understands a container: prefix wherever a file: prefix is accepted, temporarily copying the file into the container, and the emacs-mode is aware of that


  • Operations now include a block hash in their header. Such an operation could only be included in a successor of this block.
  • The economics protocol now refuses blocks that includes an operation forged more than 64 blocks in the past. As any constants set by the economic protocol, it is amendable by a vote.
  • Header of blocks now includes a hash of the “context” that result from its validation. This is currently the SHA1 of the git commit, but this will be changed in a near future for a safer cryptographic hash.
  • The node does not need anymore to maintain a full index of the operation to operate. This greatly reduce the memory and disk usage.
  • The node now builds against irmin.1.3 where some of our code and optimizations were upstreamed. We were previously stuck to irmin.0.12.


  • This is not directly visible in the alphanet, but our CI infrastructure is now ready for open development. More about that soon (or later).