A self-amending cryptographic ledger
OCaml Makefile Other
Latest commit 48a88d1 Feb 16, 2017 @tezos committed with Benjamin Canou Merge branch 'limit_hashtbl_size' into 'master'
Shell: limit known points table size

See merge request !138



Tezos is a distributed consensus platform with meta-consensus capability. Tezos not only comes to consensus about state, like BTC or ETH. It also comes to consensus about how the protocol and the nodes should adapt and upgrade.

See https://www.tezos.com/ for more information about the project.

Build instructions

To compile Tezos, you need an OCaml compiler (version 4.03.0) and all the libraries listed in src/tezos-deps.opam.

The best way to install all dependencies is by first installing OPAM, the OCaml package manager.

Create a new switch alias for Tezos. A switch is your own version of the OPAM configuration, including the OCaml compiler, all packages, and package manager configuration related to your project. This is necessary so that the project doesn't conflict with other OCaml projects or other versions of Tezos.

opam switch tezos --alias-of 4.03.0

Activate the new switch:

eval `opam config env`

Install Tezos dependencies:

make build-deps

Compile the project:


This should produce three binaries:

  • tezos-node: the tezos daemon itself;
  • tezos-client: a minimal command-line client;
  • tezos-protocol-compiler: a protocol compiler used for developing new version of the economical protocol.

Currently Tezos is being developed for Linux only. It should work on mac OS, but it has not been tested recently. A Windows port is in progress.

Running the node in a sandbox

To run a single instance of a Tezos node in sandbox mode:

./tezos-node run --sandbox --rpc-addr localhost:8732

This "sandboxed" node will not participate in the P2P network, but will accept RPC from localhost on port 8732. See below from more details on the RPC interface.

Running the node

So far there is no official Tezos network being run, but you might run a local test network. Use the following command to run a node that will accept incoming connections:

./tezos-node identity generate 24.

This will first generate a new node identity and compute the associated stamp of proof-of-work. Then, the node will listen to connections coming in on [::]:9732. All used data is stored at $HOME/.tezos-node/. For example, the default configuration file is at $HOME/.tezos-node/config.json.

To run multiple nodes on the same machine, you can duplicate and edit $HOME/.tezos-node/config.json while making sure they don't share paths to the database or any other data file (cf. options db.store ; db.context ; db.protocol, net.peers-metadata and net.identity).

You could also let Tezos generate a config file by specifying options on the command line. For instance, if $dir/config.json does not exist, the following command will generate it and replace the default values with the values from the command line:

./tezos-node run --data-dir "$dir" --net-addr localhost:9733

The Tezos server has a built-in mechanism to discover peers on the local network (using UDP packets broadcasted on port 7732).

If this mechanism is not sufficient, one can provide Tezos with a list of initial peers, either by editing the option net.bootstrap-peers in the config.json file, or by specifying a command line parameter:

./tezos-node run \
             --data-dir "$dir" --net-addr localhost:2023 \
             --peer localhost:2021 --peer localhost:2022

If "$dir"/config.json exists, the command line options override those read in the config file. By default, Tezos won't modify the content of an existing "$dir"/config.json file. But, you may explicit ask the node to reset or to update the file according to the command line parameters with the following commands line:

./tezos-node config reset --data-dir "$dir" --net-addr localhost:9733
./tezos-node config update --data-dir "$dir" --net-addr localhost:9734

Configuration options

Here is an example configuration file with all parameters specified. Most of the time it uses default values, except for cases where the default is not explanatory enough (i.e. "bootstrap-peers" is an empty list by default). Comments are not allowed in JSON, so this configuration file would not parse. They are just provided here to help writing your own configuration file if needed.


  /* Location of the data dir on disk. */

  "data-dir": "/home/tezos/my_data_dir"

  /* Configuration of net parameters */

  "net": {

    /* Floating point number between 0 and 256 that represents a
    difficulty, 24 signifies for example that at least 24 leading
    zeroes are expected in the hash. */

    "expected-proof-of-work": 24.5,

    /* List of hosts. Tezos can connect to both IPv6 and IPv4
    hosts. If the port is not specified, default port 9732 will be
    assumed. */

    "bootstrap-peers": ["::1:10732", "::ffff:", "mynode.tezos.com"],

    /* Specify if the network is closed or not. A closed network
    allows only peers listed in "bootstrap-peers". */

    "closed": false,

    /* Network limits */

    "limits": {

      /* Delay granted to a peer to perform authentication, in
      seconds. */

      "authentication-timeout": 5,

      /* Strict minimum number of connections (triggers an urgent
      maintenance). */

      "min-connections": 50,

      /* Targeted number of connections to reach when bootstraping /
      maintaining. */

      "expected-connections": 100,

      /* Maximum number of connections (exceeding peers are
      disconnected). */

      "max-connections": 200,

      /* Number above which pending incoming connections are
      immediately rejected. */

      "backlog": 20,

      /* Maximum allowed number of incoming connections that are
      pending authentication. */

      "max-incoming-connections": 20,

      /* Max download and upload speeds in KiB/s. */

      "max-download-speed": 1024,
      "max-upload-speed": 1024,

      /* Size of the buffer passed to read(2). */

      "read-buffer-size": 16384,

  /* Configuration of rpc parameters */

  "rpc": {

    /* Host to listen to. If the port is not specified, the default
    port 8732 will be assumed. */

    "listen-addr": "localhost:8733",

    /* Cross Origin Resource Sharing parameters, see
    https://en.wikipedia.org/wiki/Cross-origin_resource_sharing. */

    "cors-origin": [],
    "cors-headers": [],

    /* Certificate and key files (necessary when TLS is used). */

    "crt": "tezos-node.crt",
    "key": "tezos-node.key"

  /* Configuration of log parameters */

  "log": {

    /* Output for the logging function. Either "stdout", "stderr" or
    the name of a log file . */

    "output": "tezos-node.log",

    /* Verbosity level: one of 'fatal', 'error', 'warn', 'notice',
    'info', 'debug'. */

    "level": "info",

    /* Fine-grained logging instructions. Same format as described in
    `tezos-node run --help`, DEBUG section. In the example below,
    sections "net" and all sections starting by "client" will have
    their messages logged up to the debug level, whereas the rest of
    log sections will be logged up to the notice level. */

    "rules": "client* -> debug, net -> debug, * -> notice",

    /* Format for the log file, see
    http://ocsigen.org/lwt/dev/api/Lwt_log_core#2_Logtemplates. */

    "template": "$(date) - $(section): $(message)"


It is possible to set independant log levels for different logging sections in Tezos, as well as specifying an output file for logging. See the description of log parameters above as well as documentation under the DEBUG section diplayed by `tezos-node run --help'.

JSON/RPC interface

The Tezos node provides a JSON/RPC interface. Note that it is an RPC, and it is JSON based, but it does not follow the "JSON-RPC" protocol. It is not active by default and it must be explicitely activated with the --rpc-addr option. Typically, if you are not trying to run a local network and just want to explore the RPC, you would run:

./tezos-node run --sandbox --rpc-addr localhost

The RPC interface is self-documented and the tezos-client executable is able to pretty-print the RPC API. For instance, to see the API provided by the Tezos Shell:

./tezos-client rpc list

To get API attached to the "genesis" block, including the remote procedures provided by the associated economical protocol version:

./tezos-client rpc list /blocks/genesis/

You might also want the JSON schema describing the expected input and output of a RPC. For instance:

./tezos-client rpc schema /blocks/genesis/hash

Note: you can get the same information, but as a raw JSON object, with a simple HTTP request:

wget --post-data '{ "recursive": true }' -O - http://localhost:8732/describe
wget --post-data '{ "recursive": true }' -O - http://localhost:8732/describe/blocks/genesis
wget -O - http://localhost:8732/describe/blocks/genesis/hash

The minimal CLI client

Work in progress.

See ./tezos-client -help for available commands.