Configuration (Conf) Files

Conf files are an alternative way for setting arguments for the  certoraRun tool. In terms of functionality using conf files is identical to the use of the CLI Options. Instead of calling certoraRun with a list of shell flags, some or all the flags can be stored in a JSON file (to be more precise the format is JSON5):

certoraRun my_params.conf

Conf files must use the .conf suffix.

How CLI options are mapped to JSON

Command-line arguments are stored as key-value pairs in the conf file. The keys are the names of the CLI options (with the leading -- removed). For example,

certoraRun --verify Example:example.spec

is equivalent to running with the following conf file:

{ "verify": "Example:example.spec" }

The values in the map depend on the type of arguments:

  • The input files in the CLI API will be stored as a list under the key files. For example,

    certoraRun example.sol  ...

    will appear in the conf file as:

      "files": [ "example.sol" ], 
  • Boolean options are options that take no arguments (for example --multi_assert_check). In the conf file all keys must come with a value, the value for boolean options is true. Since the default value of boolean options is false there is no need to set a boolean attribute to values other than true. For example,

    certoraRun --multi_assert_check

    would be encoded as:

    { "multi_assert_check": true }
  • Options that expect a single argument (for example --solc or --loop_iter) are encoded as a JSON string. For example,

    certoraRun --solc solc4.25 --loop_iter 2

    would be encoded as:

    { "solc": "solc4.25", "loop_iter": "2" }

    Note that in conf files numbers are also encoded as strings.

  • Options that expect multiple arguments (for example --packages) are encoded as JSON lists. For example,

    certoraRun --packages @balancer-labs/v2-solidity-utils=pkg/solidity-utils \
    would be encoded as:
      "packages": [
  • Options that are maps (--compiler_map and --solc_optimize_map) will be stored as JSON objects. For example,

    certoraRun --solc_map A=solc5.11,B=solc5.9,C=solc6.8

    would be encoded as:

  "solc_map": {
    "A": "solc5.11",
    "B": "solc5.9",
    "C": "solc6.8"

certoraRun --solc_optimize_map A=200,B=200,C=300

would be encoded as:

  "solc_optimize_map": {
    "A": "200",
    "B": "200",
    "C": "300"

Generating a conf file

After each successful run of certoraRun a conf file is generated and is stored in the file run.conf under the internal directory of that run. The conf file of the latest run can be found in:


Instead of generating a complete conf file from scratch, users can take one of these generated conf files as a basis for their modifications.

Conf files in the VS Code IDE extension

The Certora IDE Extension automatically generates conf files for each configured job; these conf files are stored in the VS Code project under the folder  certora/confs. Once the job is completed, a link to the job’s conf file can also be found in the files section of the run report.

Complete example

The command line

certoraRun SolcArgs/A.sol SolcArgs/A.sol:B SolcArgs/C.sol \
  --verify A:SolcArgs/Trigger.spec \
  --solc_map SolcArgs/A.sol=solc6.1,B=solc6.1,C=solc5.12 \

will generate the conf file below:

    "files": [
    "multi_assert_check": true,
    "solc_map": {
        "B": "solc6.1",
        "C": "solc5.12",
        "SolcArgs/A.sol": "solc6.1"
    "verify": "A:SolcArgs/Trigger.spec"