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.
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.
- 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 thebuild_dependencies
for the current package.- For every
pn
wheren > 1
,pn
must be present in the keys of thebuild_dependencies
of the package forpn-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 thelength
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
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 thebuild_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 thecontract_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 expression0x[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).