Package Specification¶

This document defines the specification for a Package. The Package JSON document provides metadata about itself and in most cases should provide sufficient information about the packaged contracts and its dependencies to do bytecode verification of its contracts.

Guiding Principles¶

The Package specification makes the following assumptions about the document lifecycle.

Packages are intended to be generated programatically by package management software as part of the release process.
Packages will be consumed by package managers during tasks like installing package dependencies or building and deploying new releases.
Packages will typically not be stored alongside the source, but rather by package registries or referenced by package registries and stored in something akin to IPFS.

Keywords¶

RFC2119¶

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in RFC 2119.

https://www.ietf.org/rfc/rfc2119.txt

Custom¶

Prefixed vs Unprefixed¶

A prefixed hexadecimal value begins with '0x'. Unprefixed values have no prefix. Unless otherwise specified, all hexadecimal values should be represented with the '0x' prefix.

Prefixed: 0xdeadbeef

Unprefixed: deadbeef

Contract Name¶

The name found in the source code which defines a specific Contract Type. These names must conform to the regular expression [a-zA-Z][-a-zA-Z0-9_]{0,255}

There can be multiple contracts with the same contract name in a projects source files.

Contract Alias¶

This is a name used to reference a specific Contract Type. Contract aliases must be unique within a single Package.

The contract alias must use one of the following naming schemes.

<contract-name>
<contract-name>[<identifier>]

The <contract-name> portion must be the same as the contract name for this contract type.

The [<identifier>] portion must match the regular expression \[[-a-zA-Z0-9]{1,256}\].

Contract Instance Name¶

A name which refers to a specific Contract Instance on a specific chain from the deployments of a single Package. This name must be unique across all other contract instances for the given chain. The name must conform to the regular expression [a-zA-Z][a-zA-Z0-9_]{0,255}

In cases where there is a single deployed instance of a given Contract Type, package managers should use the contract alias for that contract type for this name.

In cases where there are multiple deployed instances of a given contract type, package managers should use a name which provides some added semantic information as to help differentiate the two deployed instances in a meaningful way.

Identifier¶

A string matching the regular expression [a-zA-Z][-_a-zA-Z0-9]{0,255}

Package Name¶

A string matching the regular expression [a-zA-Z][-_a-zA-Z0-9]{0,255}

Content Addressable URI¶

Any URI which contains a cryptographic hash which can be used to verify the integrity of the content found at the URI.

The URI format is defined in RFC3986

It is recommended that tools support IPFS and Swarm.

Chain Definition¶

This definition originates from BIP122 URI.

A URI in the format blockchain://<chain_id>/block/<block_hash>

chain_id is the unprefixed hexadecimal representation of the genesis hash for the chain.
block_hash is the unprefixed hexadecimal representation of the hash of a block on the chain.

A chain is considered to match a chain definition if the the genesis block hash matches the chain_id and the block defined by block_hash can be found on that chain. It is possible for multiple chains to match a single URI, in which case all chains are considered valid matches

Format¶

The canonical format for the Package JSON document containing a single JSON object. Packages must conform to the following serialization rules.

The document must be tightly packed, meaning no linebreaks or extra whitespace.
The keys in all objects must be sorted alphabetically.
Duplicate keys in the same object are invalid.
The document must use UTF-8 encoding.
The document must not have a trailing newline.

Document Specification¶

The following fields are defined for the Package. Custom fields may be included. Custom fields should be prefixed with x- to prevent name collisions with future versions of the specification.

EthPM Manifest Version: `manifest_version`¶

The manifest_version field defines the specification version that this document conforms to. Packages must include this field.

Required: Yes

Key: manifest_version

Type: String

Allowed Values: 2

Package Name: `package_name`¶

The package_name field defines a human readable name for this package. Packages must include this field. Package names must begin with a lowercase letter and be comprised of only lowercase letters, numeric characters, and the dash character '-'. Package names must not exceed 214 characters in length.

Required: Yes

Key: package_name

Type: String

Format: must be a valid package name.

Package Meta: `meta`¶

The meta field defines a location for metadata about the package which is not integral in nature for package installation, but may be important or convenient to have on-hand for other reasons. This field should be included in all Packages.

Required: No

Key: meta

Type: Object (String: Package Meta object)

Version: `version`¶

The version field declares the version number of this release. This value must be included in all Packages. This value should conform to the semver version numbering specification.

Required: Yes

Key: version

Type: String

Sources: `sources`¶

The sources field defines a source tree that should comprise the full source tree necessary to recompile the contracts contained in this release. Sources are declared in a key/value mapping.

Key:
sources

Type:
Object (String: String)

Format:

Keys must be relative filesystem paths beginning with a ./. Paths must resolve to a path that is within the current working directory.

Values must conform to one of the following formats.

Source string.

When the value is a source string the key should be interpreted as a file path.

Content Addressable URI.

If the resulting document is a directory the key should be interpreted as a directory path.

If the resulting document is a file the key should be interpreted as a file path.

Contract Types: `contract_types`¶

The contract_types field holds the Contract Types which have been included in this release. Packages should only include contract types that can be found in the source files for this package. Packages should not include contract types from dependencies.

Key:
contract_types

Type:
Object (String: Contract Type Object)

Format:

Keys must be valid contract aliases.

Values must conform to the Contract Type Object definition.

Packages should not include abstract contracts in the contract types section of a release.

Deployments: `deployments`¶

The deployments field holds the information for the chains on which this release has Contract Instances as well as the Contract Types and other deployment details for those deployed contract instances. The set of chains defined by the BIP122 URI keys for this object must be unique.

Key:
deployments

Type:
Object (String: Object(String: Contract Instance Object))

Format:

Keys must be a valid BIP122 URI chain definition.

Values must be objects which conform to the format:

Keys must be a valid Contract Instance Name.

Values must be a valid Contract Instance Object.

Build Dependencies: `build_dependencies`¶

The build_dependencies field defines a key/value mapping of ethereum packages that this project depends on.

Key:
dependencies

Type:
Object (String: String)

Format:

Keys must be valid package names matching the regular expression [a-z][-a-z0-9]{0,213}

Values must be valid IPFS URIs which resolve to a valid Package

Definitions¶

Definitions for different objects used within the Package. All objects allow custom fields to be included. Custom fields should be prefixed with x- to prevent name collisions with future versions of the specification.

The Link Reference Object¶

A |LinkReference| object has the following key/value pairs. All link references are assumed to be associated with some corresponding bytecode.

Offsets: `offsets`¶

The offsets field is an array of integers, corresponding to each of the start positions where the link reference appears in the bytecode. Locations are 0-indexed from the beginning of the bytes representation of the corresponding bytecode. This field is invalid if it references a position that is beyond the end of the bytecode.

Required: Yes

Type: Array

Length: `length`¶

The length field is an integer which defines the length in bytes of the link reference. This field is invalid if the end of the defined link reference exceeds the end of the bytecode.

Required: Yes

Type: Integer

Name: `name`¶

The name field is a string which must be a valid Identifier. Any link references which should be linked with the same link value should be given the same name.

Required: No

Type: String

Format: must conform to the Identifier format.

The Link Value Object¶

A |LinkValue| object is defined to have the following key/value pairs.

Offsets: `offsets`¶

The offsets field defines the locations within the corresponding bytecode where the value for this link value was written. These locations are 0-indexed from the beginning of the bytes representation of the corresponding bytecode.

Required:
Yes

Type:
Integer

Format:
Array of integers, where each integer must conform to all of the following:

be greater than or equal to zero

strictly less than the length of the unprefixed hexadecimal representation of the corresponding bytecode.

Type: `type`¶

The type field defines the value type for determining what is encoded when linking the corresponding bytecode.

Required:
Yes

Type:
String

Allowed Values:

'literal' for bytecode literals

'reference' for named references to a particular Contract Instance

Value: `value`¶

The value field defines the value which should be written when linking the corresponding bytecode.

Required:
Yes

Type:
String

Format:
determined based on type:

Type literal

For static value literals (e.g. address), value must be a byte string

Type reference

To reference the address of a Contract Instance from the current package the value should be the name of that contract instance.

This value must be a valid contract instance name.

The chain definition under which the contract instance that this link value belongs to must contain this value within its keys.

This value may not reference the same contract instance that this link value belongs to.

To reference a contract instance from a Package from somewhere within the dependency tree the value is constructed as follows.

Let [p1, p2, .. pn] define a path down the dependency tree.

Each of p1, p2, pn must be valid package names.

p1 must be present in keys of the build_dependencies for the current package.

For every pn where n > 1, pn must be present in the keys of the build_dependencies of the package for pn-1.

The value is represented by the string <p1>:<p2>:<...>:<pn>:<contract-instance> where all of <p1>, <p2>, <pn> are valid package names and <contract-instance> is a valid contract name.

The <contract-instance> value must be a valid contract instance name.

Within the package of the dependency defined by <pn>, all of the following must be satisfiable:

There must be exactly one chain defined under the deployments key which matches the chain definition that this link value is nested under.

The <contract-instance> value must be present in the keys of the matching chain.

The Bytecode Object¶

A bytecode object has the following key/value pairs.

Bytecode: `bytecode`¶

The bytecode field is a string containing the 0x prefixed hexadecimal representation of the bytecode.

Required: Yes

Type: String

Format: 0x prefixed hexadecimal.

Link References: `link_references`¶

The link_references field defines the locations in the corresponding bytecode which require linking.

Required: No

Type: Array

Format: All values must be valid Link Reference objects

This field is considered invalid if any of the Link References are invalid when applied to the corresponding bytecode field, or if any of the link references intersect.

Intersection is defined as two link references which overlap.

Link Dependencies: `link_dependencies`¶

The link_dependencies defines the Link Values that have been used to link the corresponding bytecode.

Required: No
Type: Array
Format: All values must be valid Link Value objects

Validation of this field includes the following:

No two link value objects may contain any of the same values for offsets.
Each link value object must have a corresponding link reference object under the link_references field.
The length of the resolved value must be equal to the length of the corresponding Link Reference.

The Package Meta Object¶

The Package Meta object is defined to have the following key/value pairs.

Authors: `authors`¶

The authors field defines a list of human readable names for the authors of this package. Packages may include this field.

Required: No

Key: authors

Type: List of Strings

License: `license`¶

The license field declares the license under which this package is released. This value should conform to the SPDX format. Packages should include this field.

Required: No

Key: license

Type: String

Description: `description`¶

The description field provides additional detail that may be relevant for the package. Packages may include this field.

Required: No

Key: description

Type: String

Keywords: `keywords`¶

The keywords field provides relevant keywords related to this package.

Required: No

Key: keywords

Type: List of Strings

Links: `links`¶

The links field provides URIs to relevant resources associated with this package. When possible, authors should use the following keys for the following common resources.

website: Primary website for the package.

documentation: Package Documentation

repository: Location of the project source code.

Key: links

Type: Object (String: String)

The Contract Type Object¶

A Contract Type object is defined to have the following key/value pairs.

Contract Name: `contract_name`¶

The contract_name field defines the contract name for this Contract Type.

Required: If the contract name and contract alias are not the same.

Type: String

Format: must be a valid contract name.

Deployment Bytecode: `deployment_bytecode`¶

The deployment_bytecode field defines the bytecode for this Contract Type.

Required: No

Type: Object

Format: must conform to the Bytecode Object format.

Runtime Bytecode: `runtime_bytecode`¶

The runtime_bytecode field defines the unlinked '0x' prefixed runtime portion of Bytecode for this Contract Type.

Required: No

Type: Object

Format: must conform to the Bytecode Object format.

ABI: `abi`¶

Required: No

Type: List

Format: see https://github.com/ethereum/wiki/wiki/Ethereum-Contract-ABI#json

Natspec: `natspec`¶

Required:
No

Type:
Object

Format:
The Merged UserDoc and DevDoc

UserDoc

DevDoc

Compiler: `compiler`¶

Required: No

Type: Object

Format: must conform to the Compiler Information object format.

The Contract Instance Object¶

A |ContractInstance| Object is defined to have the following key/value pairs.

Contract Type: `contract_type`¶

The contract_type field defines the Contract Type for this Contract Instance. This can reference any of the contract types included in this Package or any of the contract types found in any of the package dependencies from the build_dependencies section of the Package Manifest.

Required: Yes

Type: String

Format: must conform to one of the following formats

To reference a contract type from this Package, use the format <contract-alias>.

The <contract-alias> value must be a valid contract alias.
The value must be present in the keys of the contract_types section of this Package.

To reference a contract type from a dependency, use the format <package-name>:<contract-alias>.

The <package-name> value must be present in the keys of the build_dependencies of this Package.
The <contract-alias> value must be be a valid contract alias.
The resolved package for <package-name> must contain the <contract-alias> value in the keys of the contract_types section.

Address: `address`¶

The address field defines the Address of the Contract Instance.

Required: Yes

Type: String

Format: Hex encoded '0x' prefixed Ethereum address matching the regular expression 0x[0-9a-fA-F]{40}.

Transaction: `transaction`¶

The transaction field defines the transaction hash in which this Contract Instance was created.

Required: No

Type: String

Format: 0x prefixed hex encoded transaction hash.

Block: `block`¶

The block field defines the block hash in which this the transaction which created this contract instance was mined.

Required: No

Type: String

Format: 0x prefixed hex encoded block hash.

Runtime Bytecode: `runtime_bytecode`¶

The runtime_bytecode field defines the runtime portion of bytecode for this Contract Instance. When present, the value from this field supersedes the runtime_bytecode from the Contract Type for this Contract Instance.

Required: No

Type: Object

Format: must conform to the Bytecode Object format.

Every entry in the link_references for this bytecode must have a corresponding entry in the link_dependencies section.

Compiler: `compiler`¶

The compiler field defines the compiler information that was used during compilation of this Contract Instance. This field should be present in all Contract Types which include bytecode or runtime_bytecode.

Required: No

Type: Object

Format: must conform to the Compiler Information Object format.

The Compiler Information Object¶

The compiler field defines the compiler information that was used during compilation of this Contract Instance. This field should be present in all contract instances that locally declare runtime_bytecode.

A Compiler Information object is defined to have the following key/value pairs.

Name `name`¶

The name field defines which compiler was used in compilation.

Required: Yes

Key: type:

Type: String

Version: `version`¶

The version field defines the version of the compiler. The field should be OS agnostic (OS not included in the string) and take the form of either the stable version in semver format or if built on a nightly should be denoted in the form of <semver>-<commit-hash> ex: 0.4.8-commit.60cc1668.

Required: Yes

Key: version:

Type: String

Settings: `settings`¶

The settings field defines any settings or configuration that was used in compilation. For the 'solc' compiler, this should conform to the Compiler Input and Output Description.

Required: No

Key: settings:

Type: Object

BIP122 URIs¶

BIP122 URIs are used to define a blockchain via a subset of the BIP-122 spec.

blockchain://<genesis_hash>/block/<latest confirmed block hash>

The <genesis hash> represents the blockhash of the first block on the chain, and <latest confirmed block hash> represents the hash of the latest block that’s been reliably confirmed (package managers should be free to choose their desired level of confirmations).

Package Specification¶

Guiding Principles¶

Keywords¶

RFC2119¶

Custom¶

Prefixed vs Unprefixed¶

Contract Name¶

Contract Alias¶

Contract Instance Name¶

Identifier¶

Package Name¶

Content Addressable URI¶

Chain Definition¶

Format¶

Document Specification¶

EthPM Manifest Version: manifest_version¶

Package Name: package_name¶

Package Meta: meta¶

Version: version¶

Sources: sources¶

Contract Types: contract_types¶

Deployments: deployments¶

Build Dependencies: build_dependencies¶

Definitions¶

The Link Reference Object¶

Offsets: offsets¶

Length: length¶

Name: name¶

The Link Value Object¶

Offsets: offsets¶

Type: type¶

Value: value¶

The Bytecode Object¶

Bytecode: bytecode¶

Link References: link_references¶

Link Dependencies: link_dependencies¶

The Package Meta Object¶

Authors: authors¶

License: license¶

Description: description¶

Keywords: keywords¶

Links: links¶

The Contract Type Object¶

Contract Name: contract_name¶

Deployment Bytecode: deployment_bytecode¶

Runtime Bytecode: runtime_bytecode¶

ABI: abi¶

Natspec: natspec¶

Compiler: compiler¶

The Contract Instance Object¶

Contract Type: contract_type¶

Address: address¶

Transaction: transaction¶

Block: block¶

Runtime Bytecode: runtime_bytecode¶

Compiler: compiler¶

The Compiler Information Object¶

Name name¶

Version: version¶

Settings: settings¶

BIP122 URIs¶

EthPM Manifest Version: `manifest_version`¶

Package Name: `package_name`¶

Package Meta: `meta`¶

Version: `version`¶

Sources: `sources`¶

Contract Types: `contract_types`¶

Deployments: `deployments`¶

Build Dependencies: `build_dependencies`¶

Offsets: `offsets`¶

Length: `length`¶

Name: `name`¶

Offsets: `offsets`¶

Type: `type`¶

Value: `value`¶

Bytecode: `bytecode`¶

Link References: `link_references`¶

Link Dependencies: `link_dependencies`¶

Authors: `authors`¶

License: `license`¶

Description: `description`¶

Keywords: `keywords`¶

Links: `links`¶

Contract Name: `contract_name`¶

Deployment Bytecode: `deployment_bytecode`¶

Runtime Bytecode: `runtime_bytecode`¶

ABI: `abi`¶

Natspec: `natspec`¶

Compiler: `compiler`¶

Contract Type: `contract_type`¶

Address: `address`¶

Transaction: `transaction`¶

Block: `block`¶

Runtime Bytecode: `runtime_bytecode`¶

Compiler: `compiler`¶

Name `name`¶

Version: `version`¶

Settings: `settings`¶