diff --git a/apps/aecore/include/common.hrl b/apps/aecore/include/common.hrl
new file mode 100644
index 0000000000..82027ffbe4
--- /dev/null
+++ b/apps/aecore/include/common.hrl
@@ -0,0 +1 @@
+-type(pubkey() :: binary()).
diff --git a/apps/aecore/include/trees.hrl b/apps/aecore/include/trees.hrl
index 010ba5d87f..01d99b548e 100644
--- a/apps/aecore/include/trees.hrl
+++ b/apps/aecore/include/trees.hrl
@@ -1,4 +1,13 @@
--record(trees, {}).
+-include("common.hrl").
+
+-record(trees, {
+          accounts}).
 -type(trees() :: #trees{}).
 
 %% Placeholder to define state Merkle trees
+
+-record(account, {
+          pubkey = <<>>  :: pubkey(),
+          balance = 0    :: non_neg_integer(),
+          nonce = 0      :: non_neg_integer(),
+          height = 0     :: non_neg_integer()}).
diff --git a/apps/aecore/include/txs.hrl b/apps/aecore/include/txs.hrl
index ec733795ac..ebad6bdd2a 100644
--- a/apps/aecore/include/txs.hrl
+++ b/apps/aecore/include/txs.hrl
@@ -1,4 +1,4 @@
--type(pubkey() :: binary()).
+-include("common.hrl").
 
 -record(coinbase_tx, {
           account = <<>> :: pubkey(),
diff --git a/apps/aecore/src/aec_accounts.erl b/apps/aecore/src/aec_accounts.erl
new file mode 100644
index 0000000000..8eb29a9802
--- /dev/null
+++ b/apps/aecore/src/aec_accounts.erl
@@ -0,0 +1,32 @@
+-module(aec_accounts).
+
+%% API
+-export([get/2,
+         get_with_proof/2,
+         put/2,
+         earn/3]).
+
+-include("trees.hrl").
+
+get(Pubkey, _AccountsTree) ->
+    %% To be implemented when we have state Merkle trees
+    %% to hold accounts with balances
+    Account = #account{pubkey = Pubkey,
+                       balance = 0},
+    {ok, Account}.
+
+get_with_proof(Pubkey, _AccountsTree) ->
+    %% To be implemented when we have state Merkle trees
+    %% to hold accounts with balances
+    Account = #account{pubkey = Pubkey,
+                       balance = 0},
+    {ok, {Account, <<"fakeproof">>}}.
+
+put(_Account, AccountsTrees) ->
+    %% To be implemented when we have state Merkle trees
+    %% to hold accounts with balances
+    {ok, AccountsTrees}.
+
+earn(#account{balance = Balance0}, Amount, Height) ->
+    {ok, #account{balance = Balance0 + Amount,
+                  height = Height}}.
diff --git a/apps/aecore/src/pow_sha256.erl b/apps/aecore/src/aec_pow_sha256.erl
similarity index 96%
rename from apps/aecore/src/pow_sha256.erl
rename to apps/aecore/src/aec_pow_sha256.erl
index feb71904c3..c0a1301b2b 100644
--- a/apps/aecore/src/pow_sha256.erl
+++ b/apps/aecore/src/aec_pow_sha256.erl
@@ -4,7 +4,7 @@
 %%%    Module dealing with SHA256 Proof of Work calculation and hash generation
 %%% @end
 %%%=============================================================================
--module(pow_sha256).
+-module(aec_pow_sha256).
 
 -export([generate/3,
          recalculate_difficulty/3,
@@ -64,8 +64,8 @@ generate_with_nonce(_Data, _Difficulty, _Nonce, 0) ->
     %% Count exhausted: fail
     {error, generation_count_exhausted};
 generate_with_nonce(Data, Difficulty, Nonce, Count) ->
-    Hash1 = sha256:hash(Data),
-    Hash2 = sha256:hash(<<Hash1/binary, Difficulty:16, Nonce:?HASH_BITS>>),
+    Hash1 = aec_sha256:hash(Data),
+    Hash2 = aec_sha256:hash(<<Hash1/binary, Difficulty:16, Nonce:?HASH_BITS>>),
     case binary_to_scientific(Hash2) of
         HD when HD < Difficulty ->
             %% Hash satisfies condition: return nonce
diff --git a/apps/aecore/src/sha256.erl b/apps/aecore/src/aec_sha256.erl
similarity index 97%
rename from apps/aecore/src/sha256.erl
rename to apps/aecore/src/aec_sha256.erl
index aaf24e8fa9..427674f7ef 100644
--- a/apps/aecore/src/sha256.erl
+++ b/apps/aecore/src/aec_sha256.erl
@@ -5,7 +5,7 @@
 %%% @end
 %%%=============================================================================
 
--module(sha256).
+-module(aec_sha256).
 
 -export([hash/1]).
 
diff --git a/apps/aecore/src/aec_trees.erl b/apps/aecore/src/aec_trees.erl
new file mode 100644
index 0000000000..1d8ec4d4d8
--- /dev/null
+++ b/apps/aecore/src/aec_trees.erl
@@ -0,0 +1,13 @@
+-module(aec_trees).
+
+-include("trees.hrl").
+
+%% API
+-export([accounts/1,
+         with_accounts/2]).
+
+accounts(Trees) ->
+    Trees#trees.accounts.
+
+with_accounts(Trees, Accounts) ->
+    Trees#trees{accounts = Accounts}.
diff --git a/apps/aecore/src/txs/aec_coinbase_tx.erl b/apps/aecore/src/txs/aec_coinbase_tx.erl
new file mode 100644
index 0000000000..aeeedb7e1c
--- /dev/null
+++ b/apps/aecore/src/txs/aec_coinbase_tx.erl
@@ -0,0 +1,26 @@
+-module(aec_coinbase_tx).
+
+%% API
+-export([new/2, run/3]).
+
+-behavior(aec_tx).
+
+-include("txs.hrl").
+
+-define(BLOCK_MINE_REWARD, 10). %% To be set in governance
+
+
+new(#{account := AccountPubkey}, Trees) ->
+    AccountsTrees = aec_trees:accounts(Trees),
+    {ok, {_Account, Proof}} = aec_accounts:get_with_proof(AccountPubkey, AccountsTrees),
+    {ok, {#coinbase_tx{account = AccountPubkey}, [Proof]}}.
+
+run(#coinbase_tx{account = AccountPubkey}, Trees0, Height) ->
+    AccountsTrees0 = aec_trees:accounts(Trees0),
+    {ok, Account0} = aec_accounts:get(AccountPubkey, AccountsTrees0),
+
+    {ok, Account} = aec_accounts:earn(Account0, ?BLOCK_MINE_REWARD, Height),
+
+    {ok, AccountsTrees} = aec_accounts:put(Account, AccountsTrees0),
+    Trees = aec_trees:with_accounts(Trees0, AccountsTrees),
+    {ok, Trees}.
diff --git a/apps/aecore/src/txs/aec_tx.erl b/apps/aecore/src/txs/aec_tx.erl
new file mode 100644
index 0000000000..6e50b8bbe0
--- /dev/null
+++ b/apps/aecore/src/txs/aec_tx.erl
@@ -0,0 +1,9 @@
+-module(aec_tx).
+
+-include("trees.hrl").
+
+-callback new(Args :: map(), Trees :: trees()) ->
+    {ok, {Tx :: term(), Proofs :: list()}}.
+
+-callback run(Tx :: term(), Trees :: trees(), Height :: non_neg_integer()) ->
+    {ok, NewTrees :: trees()}.
diff --git a/apps/aecore/test/pow_sha256_tests.erl b/apps/aecore/test/aec_pow_sha256_tests.erl
similarity index 95%
rename from apps/aecore/test/pow_sha256_tests.erl
rename to apps/aecore/test/aec_pow_sha256_tests.erl
index 25c09cca8b..8da95a6f11 100644
--- a/apps/aecore/test/pow_sha256_tests.erl
+++ b/apps/aecore/test/aec_pow_sha256_tests.erl
@@ -1,10 +1,10 @@
 %%%=============================================================================
 %%% @copyright (C) 2017, Aeternity Anstalt
 %%% @doc
-%%%   Unit tests for the pow_sha256 module
+%%%   Unit tests for the aec_pow_sha256 module
 %%% @end
 %%%=============================================================================
--module(pow_sha256_tests).
+-module(aec_pow_sha256_tests).
 
 -include_lib("eunit/include/eunit.hrl").
 
@@ -14,7 +14,7 @@
 -include_lib("eunit/include/eunit.hrl").
 -include("sha256.hrl").
 
--define(TEST_MODULE, pow_sha256).
+-define(TEST_MODULE, aec_pow_sha256).
 
 conversion_test_() ->
     {setup,
diff --git a/apps/aecore/test/sha256_tests.erl b/apps/aecore/test/aec_sha256_tests.erl
similarity index 68%
rename from apps/aecore/test/sha256_tests.erl
rename to apps/aecore/test/aec_sha256_tests.erl
index 6a29e0fff5..dca09d0351 100644
--- a/apps/aecore/test/sha256_tests.erl
+++ b/apps/aecore/test/aec_sha256_tests.erl
@@ -1,27 +1,29 @@
 %%%=============================================================================
 %%% @copyright (C) 2017, Aeternity Anstalt
 %%% @doc
-%%%   Unit tests for the sha256 module
+%%%   Unit tests for the aec_sha256 module
 %%% @end
 %%%=============================================================================
--module(sha256_tests).
+-module(aec_sha256_tests).
 
 -ifdef(TEST).
 
 -include_lib("eunit/include/eunit.hrl").
 -include("sha256.hrl").
 
+-define(TEST_MODULE, aec_sha256).
+
 all_test_() ->
     {setup,
      fun setup/0,
      fun teardown/1,
      [{"Hash a binary",
        fun() ->
-               ?assertEqual(?HASH_BYTES, size(sha256:hash(<<"hello there!">>)))
+               ?assertEqual(?HASH_BYTES, size(?TEST_MODULE:hash(<<"hello there!">>)))
        end},
       {"Hash an erlang term",
        fun() ->
-               ?assertEqual(?HASH_BYTES, size(sha256:hash({a, b, c})))
+               ?assertEqual(?HASH_BYTES, size(?TEST_MODULE:hash({a, b, c})))
        end}
      ]
     }.