A data format describing a smart contract software package.
This EIP defines a data format for package manifest documents, representing a package of one or more smart contracts, optionally including source code and any/all deployed instances across multiple networks. Package manifests are minified JSON objects, to be distributed via content addressable storage networks, such as IPFS. Packages are then published to on-chain EthPM registries, defined in EIP-1319, from where they can be freely accessed.
This document presents a natural language description of a formal specification for version 3 of this format.
This standard aims to encourage the Ethereum development ecosystem towards software best practices around code reuse. By defining an open, community-driven package data format standard, this effort seeks to provide support for package management tools development by offering a general-purpose solution that has been designed with observed common practices in mind.
"sources" object definition to support a wider range of source file types and serve as JSON input for a compiler."compilers" array in order to:
snake_case to camelCase to be
more consistent with JSON convention.This specification makes the following assumptions about the document lifecycle.
Package manifests are intended to be generated programmatically by package management software as part of the release process.
Package manifests will be consumed by package managers during tasks like installing package dependencies or building and deploying new releases.
Package manifests 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.
Package manifests can be used to verify public deployments of source contracts.
The following use cases were considered during the creation of this specification.
"metadata" field output.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.
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.
0xdeadbeefdeadbeefThe canonical format is 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.
To ensure backwards compatibility, manifest_version is a forbidden
top-level key.
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.
The manifest field defines the specification version that this
document conforms to.
manifestethpm/3The name field defines a human readable name for this package.
Packages should include this field to be released on an EthPM registry.
Package names must begin with a lowercase letter and be
comprised of only the lowercase letters a-z, numeric characters 0-9, and the
dash character -.
Package names must not exceed 255 characters in length.
version is included.name^[a-z][-a-z0-9]{0,255}$The version field declares the version number of this release.
Packages should include this field to be released on an EthPM registry.
This value should conform to the semver version numbering specification.
name is included.versionThe 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.
metaThe sources field defines a source tree that should comprise the
full source tree necessary to recompile the contracts contained in this
release.
sourcesThe contractTypes field hosts 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.
Packages should not include abstract contracts in the contract types section of a release.
contractTypesThe compilers field holds the information about the compilers and
their settings that have been used to generate the various
contractTypes included in this release.
compilersThe 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. There cannot be two different URI keys in a deployments field
representing the same blockchain.
deploymentsThe buildDependencies field defines a key/value mapping of EthPM
packages that this project depends on.
buildDependenciesDefinitions 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.
A Link Reference object has the following key/value pairs. All link references are assumed to be associated with some corresponding Bytecode.
offsetsThe 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.
lengthThe 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.
nameThe 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.
Describes a single Link Value.
A Link Value object is defined to have the following key/value pairs.
offsetsThe 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.
Format
Array of integers, where each integer must conform to all of the following.
greater than or equal to zero
strictly less than the length of the unprefixed hexadecimal representation of the corresponding bytecode.
typeThe type field defines the value type for determining what is
encoded when linking the corresponding bytecode.
"literal" for bytecode literals."reference" for named references to a particular Contract InstancevalueThe value field defines the value which should be written when linking the corresponding bytecode.
type, see below.Format
For static value literals (e.g. address), value must be a 0x-prefixed hexadecimal string representing bytes.
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 buildDependencies for the
current package.
For every pn where n > 1, pn must be present in the keys
of the buildDependencies 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.
A bytecode object has the following key/value pairs.
bytecodeThe bytecode field is a string containing the 0x prefixed
hexadecimal representation of the bytecode.
0x prefixed hexadecimal.linkReferencesThe linkReferences field defines the locations in the corresponding
bytecode which require linking.
Format
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.
linkDependenciesThe linkDependencies defines the Link Values that
have been used to link the corresponding bytecode.
Format
Validation of this field includes the following:
Two link value objects must not contain any of the same values
for offsets.
Each link value object must have a
corresponding link reference object under
the linkReferences field.
The length of the resolved value must be equal to the length
of the corresponding Link Reference.
The Package Meta object is defined to have the following key/value pairs.
The authors field defines a list of human readable names for the
authors of this package. Packages may include this field.
authorsThe license field declares the license associated with this package.
This value should conform to the
SPDX
format. Packages should include this field. If a file Source
Object defines its own license, that license takes
precedence for that particular file over this package-scoped meta
license.
licenseThe description field provides additional detail that may be relevant
for the package. Packages may include this field.
descriptionThe keywords field provides relevant keywords related to this package.
keywordsThe 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.
linksA Sources object is defined to have the following fields.
checksumHash of the source file.
content field is missing and none of the provided URLs contain a content hash.checksumurlsArray of urls that resolve to the same source file.
Urls should be stored on a content-addressable filesystem.
If they are not, then either content or checksum must be
included.
Urls must be prefixed with a scheme.
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.
content is not included.urlscontentInlined contract source. If both urls and content are provided, the content value
must match the content of the files identified in urls.
urls is not included.contentinstallPathFilesystem path of source file.
Must be a relative filesystem path that begins with a ./.
Must resolve to a path that is within the current virtual working directory.
Must be unique across all included sources.
Must not contain ../ to avoid accessing files outside of
the source folder in improper implementations.
installPathtypeThe type field declares the type of the source file. The field
should be one of the following values: solidity, vyper,
abi-json, solidity-ast-json.
typelicenseThe license field declares the type of license associated with
this source file. When defined, this license overrides the
package-scoped meta license.
licenseA Checksum object is defined to have the following key/value pairs.
algorithmThe algorithm used to generate the corresponding hash. Possible
algorithms include, but are not limited to sha3, sha256, md5,
keccak256.
hashThe hash of a source files contents generated with the corresponding
algorithm.
A Contract Type object is defined to have the following key/value pairs.
contractNameThe contractName field defines the Contract
Name for this Contract
Type.
sourceIdThe global source identifier for the source file from which this contract type was generated.
deploymentBytecodeThe deploymentBytecode field defines the bytecode for this Contract
Type.
runtimeBytecodeThe runtimeBytecode field defines the unlinked 0x-prefixed runtime
portion of Bytecode for this Contract
Type.
abiuserdocdevdocA Contract Instance Object represents a single deployed Contract Instance and is defined to have the following key/value pairs.
contractTypeThe contractType 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
buildDependencies section of the Package
Manifest.
Format
Values for this field must conform to one of the two formats herein.
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 contractTypes
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
buildDependencies 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 contractTypes section.
addressThe address field defines the Address of the
Contract Instance.
0x prefixed Ethereum address matching the regular expression ^0x[0-9a-fA-F]{40}$.transactionThe transaction field defines the transaction hash in which this
Contract Instance was created.
0x prefixed hex encoded transaction hash.blockThe block field defines the block hash in which this the transaction
which created this contract instance was mined.
0x prefixed hex encoded block hash.runtimeBytecodeThe runtimeBytecode field defines the runtime portion of bytecode for
this Contract Instance. When present, the
value from this field supersedes the runtimeBytecode from the
Contract Type for this Contract
Instance.
Every entry in the linkReferences for this bytecode must have a
corresponding entry in the linkDependencies section.
The compilers field defines the various compilers and settings used
during compilation of any Contract Types or
Contract Instance included in this package.
A Compiler Information object is defined to have the following key/value pairs.
nameThe name field defines which compiler was used in compilation.
nameversionThe 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.
versionsettingsThe 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.
settingscontractTypesA list of the Contract Alias or Contract Types in this package that used this compiler to generate its outputs.
All contractTypes that locally declare runtimeBytecode
should be attributed for by a compiler object.
A single contractTypes must not be attributed to more than one
compiler.
contractTypesBIP122 URIs are used to define a blockchain via a subset of the BIP-122 spec.
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).
The terms in this glossary have been updated to reflect the changes made in V3.
The JSON representation of the application binary interface. See the official specification for more information.
A public identifier for an account on a particular chain
The set of EVM instructions as produced by a compiler. Unless otherwise
specified this should be assumed to be hexadecimal encoded, representing
a whole number of bytes, and prefixed with 0x.
Bytecode can either be linked or unlinked. (see Linking)
0x606060405260e06000730000000000000000000000000000000000000000634d536f0x606060405260e06000736fe36000604051602001526040518160e060020a634d536fThis 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 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
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.
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}$.
A contract instance a specific deployed version of a Contract Type.
All contract instances have an Address on some specific chain.
A name which refers to a specific Contract
Instance on a specific chain from the
deployments of a single Package. This name must be
unique across all other contract instances for the given chain. The name
must conform to the regular expression
^[a-zA-Z_$][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.
The name found in the source code that defines a specific Contract
Type. These names must conform to the regular
expression ^[a-zA-Z_$][a-zA-Z0-9_$]{0,255}$.
There can be multiple contracts with the same contract name in a projects source files.
Refers to a specific contract in the package source. This term can be used to refer to an abstract contract, a normal contract, or a library. Two contracts are of the same contract type if they have the same bytecode.
Example:
A deployed instance of the Wallet contract would be of of type
Wallet.
Refers generally to a named entity in the Package.
A string matching the regular expression
^[a-zA-Z][-_a-zA-Z0-9]{0,255}$
A location within a contract’s bytecode which needs to be linked. A link reference has the following properties.
offset: Defines the location within the bytecode where the link reference begins.length: Defines the length of the reference.name: (optional) A string to identify the reference.A link value is the value which can be inserted in place of a Link Reference
The act of replacing Link References with Link Values within some Bytecode.
Distribution of an application’s source or compiled bytecode along with metadata related to authorship, license, versioning, et al.
For brevity, the term Package is often used metonymously to mean Package Manifest.
A machine-readable description of a package.
Bytecode string with leading 0x.
0xdeadbeefNot Prefixed.
deadbeefEthPM packages are distributed as alphabetically-ordered & minified JSON to ensure consistency. Since packages are published on content-addressable filesystems (eg. IPFS), this restriction guarantees that any given set of contract assets will always resolve to the same content-addressed URI.
Package names are restricted to lower-case characters, numbers, and - to improve the readability
of the package name, in turn improving the security properties for a package. A user is more likely
to accurately identify their target package with this restricted set of characters, and not confuse
a malicious package that disguises itself as a trusted package with similar but different
characters (e.g. O and 0).
The BIP-122 standard has been used since EthPM v1 since it is an industry standard URI scheme for identifying different blockchains and distinguishing between forks.
Compilers are now defined in a top-level array, simplifying the task for tooling to identify the compiler types
needed to interact with or validate the contract assets. This also removes unnecessarily duplicated
information, should multiple contractTypes share the same compiler type.
To improve understanding and readability of the EthPM spec, the
manifest_version field was updated to manifest in v3. To ensure
backwards compatibility, v3 packages must define a top-level
"manifest" with a value of "ethpm/3". Additionally,
"manifest_version" is a forbidden top-level key in v3 packages.
Using EthPM packages implicitly requires importing &/or executing code written by others. The EthPM spec guarantees that when using a properly constructed and released EthPM package, the user will have the exact same code that was included in the package by the package author. However, it is impossible to guarantee that this code is safe to interact with. Therefore, it is critical that end users only interact with EthPM packages authored and released by individuals or organizations that they trust to include non-malicious code.
Copyright and related rights waived via CC0.