Derivation

1. Property name
2. Property version
3. Property outputs
- 3.1. Property Derivation Output
4. Property inputs
- 4.1. Property srcs
  - 4.1.1. Store Path
- 4.2. Property drvs
  - 4.2.1. Pattern Property Store Path
    - 4.2.1.1. Property Output Names
      - 4.2.1.1.1. Output name
    - 4.2.1.2. Property Dynamic Outputs
      - 4.2.1.2.1. Property outputs
      - 4.2.1.2.2. Property dynamicOutputs
5. Property system
6. Property builder
7. Property args
- 7.1. args items
8. Property env
- 8.1. Property additionalProperties
9. Property structuredAttrs

Title: Derivation


Type	`object`
Required	No
Additional properties	Any type allowed

Description: Experimental JSON representation of a Nix derivation (version 4).

This schema describes the JSON representation of Nix's Derivation type.

Warning

This JSON format is currently experimental and subject to change.

Property	Type	Pattern	Title/Description
+ name	string	No	Derivation name
+ version	const	No	Format version (must be 4)
+ outputs	object	No	Output specifications
+ inputs	object	No	Derivation inputs
+ system	string	No	Build system type
+ builder	string	No	Build program path
+ args	array of string	No	Builder arguments
+ env	object	No	Environment variables
- structuredAttrs	object	No	Structured attributes

1. Property `name`

Title: Derivation name


Type	`string`
Required	Yes

Description: The name of the derivation. Used when calculating store paths for the derivation’s outputs.

2. Property `version`

Title: Format version (must be 4)


Type	`const`
Required	Yes

Description: Must be 4. This is a guard that allows us to continue evolving this format. The choice of 3 is fairly arbitrary, but corresponds to this informal version:

Version 0: ATerm format
Version 1: Original JSON format, with ugly "r:sha256" inherited from ATerm format.
Version 2: Separate method and hashAlgo fields in output specs
Version 3: Drop store dir from store paths, just include base name.
Version 4: Two cleanups, batched together to lesson churn:
- Reorganize inputs into nested structure (inputs.srcs and inputs.drvs)
- Use canonical content address JSON format for floating content addressed derivation outputs.

Note that while this format is experimental, the maintenance of versions is best-effort, and not promised to identify every change.

Specific value: 4

3. Property `outputs`

Title: Output specifications


Type	`object`
Required	Yes
Additional properties	Each additional property must conform to the schema

Description: Information about the output paths of the derivation. This is a JSON object with one member per output, where the key is the output name and the value is a JSON object as described.

Example

"outputs": {
  "out": {
    "method": "nar",
    "hashAlgo": "sha256",
    "hash": "6fc80dcc62179dbc12fc0b5881275898f93444833d21b89dfe5f7fbcbb1d0d62"
  }
}

Property	Type	Pattern	Title/Description
-	object	No	Derivation Output

3.1. Property `Derivation Output`

Title: Derivation Output


Type	`combining`
Required	No
Additional properties	Any type allowed
Defined in	#/$defs/output/overall

Description: A single output of a derivation, with different variants for different output types.

One of(Option)
Input-Addressed Output
Fixed Content-Addressed Output
Floating Content-Addressed Output
Deferred Output
Impure Output

3.1.1. Property `Input-Addressed Output`

Title: Input-Addressed Output


Type	`object`
Required	No
Additional properties	Not allowed
Defined in	#/$defs/output/inputAddressed

Description: The traditional non-fixed-output derivation type. The output path is determined from the derivation itself.

See Input-addressing derivation outputs for more details.

Property	Type	Pattern	Title/Description
+ path	string	No	Output path

3.1.1.1. Property `path`

Title: Output path


Type	`string`
Required	Yes
Defined in	store-path-v1.yaml

Description: The output path determined from the derivation itself.

Restrictions
Min length	34
Must match regular expression	`^[0123456789abcdfghijklmnpqrsvwxyz]{32}-.+$` Test

3.1.2. Property `Fixed Content-Addressed Output`

Title: Fixed Content-Addressed Output


Type	`object`
Required	No
Additional properties	Not allowed
Defined in	#/$defs/output/caFixed

Description: The output is content-addressed, and the content-address is fixed in advance.

See Fixed-output content-addressing for more details.

Property	Type	Pattern	Title/Description
+ method	enum (of string)	No	Content-Addressing Method
+ hash	string	No	Expected hash value

3.1.2.1. Property `method`

Title: Content-Addressing Method


Type	`enum (of string)`
Required	Yes
Defined in	JSON format for `ContentAddress`

Description: Method of content addressing used for this output.

Must be one of:

"flat"
"nar"
"text"
"git"

3.1.2.2. Property `hash`

Title: Expected hash value


Type	`string`
Required	Yes
Defined in	JSON format for `Hash`

Description: The expected content hash.

Examples:

"sha256-ungWv48Bz+pBQUDeXa4iI7ADYaOWF3qctBD/YfIAFa0="

"sha512-IEqPxt2oLwoM7XvrjgikFlfBbvRosiioJ5vjMacDwzWW/RXBOxsH+aodO+pXeJygMa2Fx6cd1wNU7GMSOMo0RQ=="

Restrictions
Must match regular expression	`^(blake3\|md5\|sha1\|sha256\|sha512)-[A-Za-z0-9+/]+=*$` Test

3.1.3. Property `Floating Content-Addressed Output`

Title: Floating Content-Addressed Output


Type	`object`
Required	No
Additional properties	Not allowed
Defined in	#/$defs/output/caFloating

Description: Floating-output derivations, whose outputs are content addressed, but not fixed, and so the output paths are dynamically calculated from whatever the output ends up being.

See Floating Content-Addressing for more details.

Property	Type	Pattern	Title/Description
+ method	enum (of string)	No	Content-Addressing Method
+ hashAlgo	enum (of string)	No	Hash algorithm

3.1.3.1. Property `method`

Title: Content-Addressing Method


Type	`enum (of string)`
Required	Yes
Same definition as	method

Description: Method of content addressing used for this output.

3.1.3.2. Property `hashAlgo`

Title: Hash algorithm


Type	`enum (of string)`
Required	Yes
Defined in	JSON format for `Hash`

Description: What hash algorithm to use for the given method of content-addressing.

Must be one of:

"blake3"
"md5"
"sha1"
"sha256"
"sha512"

3.1.4. Property `Deferred Output`

Title: Deferred Output


Type	`object`
Required	No
Additional properties	Any type allowed
Defined in	#/$defs/output/deferred

Description: Input-addressed output which depends on a (CA) derivation whose outputs (and thus their content-address are not yet known.

3.1.5. Property `Impure Output`

Title: Impure Output


Type	`object`
Required	No
Additional properties	Not allowed
Defined in	#/$defs/output/impure

Description: Impure output which is just like a floating content-addressed output, but this derivation runs without sandboxing. As such, we don't record it in the build trace, under the assumption that if we need it again, we should rebuild it, as it might produce something different.

Property	Type	Pattern	Title/Description
+ impure	const	No	-
+ method	enum (of string)	No	Content-Addressing Method
+ hashAlgo	enum (of string)	No	Hash algorithm

3.1.5.1. Property `impure`


Type	`const`
Required	Yes

Specific value: true

3.1.5.2. Property `method`

Title: Content-Addressing Method


Type	`enum (of string)`
Required	Yes
Same definition as	method

Description: How the file system objects will be serialized for hashing.

3.1.5.3. Property `hashAlgo`

Title: Hash algorithm


Type	`enum (of string)`
Required	Yes
Defined in	JSON format for `Hash`

Description: How the serialization will be hashed.

Must be one of:

"blake3"
"md5"
"sha1"
"sha256"
"sha512"

4. Property `inputs`

Title: Derivation inputs


Type	`object`
Required	Yes
Additional properties	Not allowed

Description: Input dependencies for the derivation, organized into source paths and derivation dependencies.

Property	Type	Pattern	Title/Description
+ srcs	array	No	Input source paths
+ drvs	object	No	Input derivations

4.1. Property `srcs`

Title: Input source paths


Type	`array`
Required	Yes

Description: List of store paths on which this derivation depends.

Example

"srcs": [
  "47y241wqdhac3jm5l7nv0x4975mb1975-separate-debug-info.sh",
  "56d0w71pjj9bdr363ym3wj1zkwyqq97j-fix-pop-var-context-error.patch"
]

	Array restrictions
Min items	N/A
Max items	N/A
Items unicity	False
Additional items	False
Tuple validation	See below

Each item of this array must be	Description
Store Path	A store path identifying a store object. ...

4.1.1. Store Path

Title: Store Path


Type	`string`
Required	No
Same definition as	path

Description: A store path identifying a store object.

This schema describes the JSON representation of store paths as used in various Nix JSON APIs.

Format

Store paths in JSON are represented as strings containing just the hash and name portion, without the store directory prefix.

For example: "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo.drv"

(If the store dir is /nix/store, then this corresponds to the path /nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo.drv.)

Structure

The format follows this pattern: ${digest}-${name}

hash: Digest rendered in a custom variant of Base32 (20 arbitrary bytes become 32 ASCII characters)
name: The package name and optional version/suffix information

4.2. Property `drvs`

Title: Input derivations


Type	`object`
Required	Yes
Additional properties	Not allowed

Description: Mapping of derivation paths to lists of output names they provide.

Example
"drvs": {
  "6lkh5yi7nlb7l6dr8fljlli5zfd9hq58-curl-7.73.0.drv": ["dev"],
  "fn3kgnfzl5dzym26j8g907gq3kbm8bfh-unzip-6.0.drv": ["out"]
}
specifies that this derivation depends on the dev output of curl, and the out output of unzip.

Property	Type	Pattern	Title/Description
- ^[0123456789abcdfghijklmnpqrsvwxyz]{32}-.+.drv$	Combination	Yes	Store Path

4.2.1. Pattern Property `Store Path`

All properties whose name matches the regular expression ^[0123456789abcdfghijklmnpqrsvwxyz]{32}-.+\.drv$ (Test) must respect the following conditions

Title: Store Path


Type	`combining`
Required	No
Additional properties	Any type allowed

Description: A store path to a derivation, mapped to the outputs of that derivation.

One of(Option)
Output Names
Dynamic Outputs

4.2.1.1. Property `Output Names`

Title: Output Names


Type	`array`
Required	No
Defined in	#/$defs/outputNames

Description: Set of names of derivation outputs to depend on

	Array restrictions
Min items	N/A
Max items	N/A
Items unicity	False
Additional items	False
Tuple validation	See below

Each item of this array must be	Description
Output name	Name of the derivation output to depend on

4.2.1.1.1. Output name

Title: Output name


Type	`string`
Required	No
Defined in	#/$defs/outputName

Description: Name of the derivation output to depend on

4.2.1.2. Property `Dynamic Outputs`

Title: Dynamic Outputs


Type	`object`
Required	No
Additional properties	Any type allowed
Defined in	#/$defs/dynamicOutputs

Description: Experimental feature: dynamic-derivations

This recursive data type allows for depending on outputs of outputs.

Property	Type	Pattern	Title/Description
- outputs	array	No	Output Names
- dynamicOutputs	object	No	Dynamic Outputs

4.2.1.2.1. Property `outputs`

Title: Output Names


Type	`array`
Required	No
Same definition as	Output Names

Description: Set of names of derivation outputs to depend on

4.2.1.2.2. Property `dynamicOutputs`

Title: Dynamic Outputs


Type	`object`
Required	No
Additional properties	Any type allowed
Same definition as	Dynamic Outputs

Description: Experimental feature: dynamic-derivations

This recursive data type allows for depending on outputs of outputs.

5. Property `system`

Title: Build system type


Type	`string`
Required	Yes

Description: The system type on which this derivation is to be built (e.g. x86_64-linux).

6. Property `builder`

Title: Build program path


Type	`string`
Required	Yes

Description: Absolute path of the program used to perform the build. Typically this is the bash shell (e.g. /nix/store/r3j288vpmczbl500w6zz89gyfa4nr0b1-bash-4.4-p23/bin/bash).

7. Property `args`

Title: Builder arguments


Type	`array of string`
Required	Yes

Description: Command-line arguments passed to the builder.

	Array restrictions
Min items	N/A
Max items	N/A
Items unicity	False
Additional items	False
Tuple validation	See below

Each item of this array must be	Description
args items	-

7.1. args items


Type	`string`
Required	No

8. Property `env`

Title: Environment variables


Type	`object`
Required	Yes
Additional properties	Each additional property must conform to the schema

Description: Environment variables passed to the builder.

Property	Type	Pattern	Title/Description
-	string	No	-

8.1. Property `additionalProperties`


Type	`string`
Required	No

9. Property `structuredAttrs`

Title: Structured attributes


Type	`object`
Required	No
Additional properties	Any type allowed

Description: Structured Attributes, only defined if the derivation contains them. Structured attributes are JSON, and thus embedded as-is.

Property	Type	Pattern	Title/Description
-	object	No	-

Determinate Nix 3.14.0 Reference Manual

Derivation

1. Property name

2. Property version

3. Property outputs

3.1. Property Derivation Output

3.1.1. Property Input-Addressed Output

3.1.1.1. Property path

3.1.2. Property Fixed Content-Addressed Output

3.1.2.1. Property method

3.1.2.2. Property hash

3.1.3. Property Floating Content-Addressed Output

3.1.3.1. Property method

3.1.3.2. Property hashAlgo

3.1.4. Property Deferred Output

3.1.5. Property Impure Output

3.1.5.1. Property impure

3.1.5.2. Property method

3.1.5.3. Property hashAlgo

4. Property inputs

4.1. Property srcs

4.1.1. Store Path

Format

Structure

4.2. Property drvs

4.2.1. Pattern Property Store Path

4.2.1.1. Property Output Names

4.2.1.1.1. Output name

4.2.1.2. Property Dynamic Outputs

4.2.1.2.1. Property outputs

4.2.1.2.2. Property dynamicOutputs

5. Property system

6. Property builder

7. Property args

7.1. args items

8. Property env

8.1. Property additionalProperties

9. Property structuredAttrs

1. Property `name`

2. Property `version`

3. Property `outputs`

3.1. Property `Derivation Output`

3.1.1. Property `Input-Addressed Output`

3.1.1.1. Property `path`

3.1.2. Property `Fixed Content-Addressed Output`

3.1.2.1. Property `method`

3.1.2.2. Property `hash`

3.1.3. Property `Floating Content-Addressed Output`

3.1.3.1. Property `method`

3.1.3.2. Property `hashAlgo`

3.1.4. Property `Deferred Output`

3.1.5. Property `Impure Output`

3.1.5.1. Property `impure`

3.1.5.2. Property `method`

3.1.5.3. Property `hashAlgo`

4. Property `inputs`

4.1. Property `srcs`

4.2. Property `drvs`

4.2.1. Pattern Property `Store Path`

4.2.1.1. Property `Output Names`

4.2.1.2. Property `Dynamic Outputs`

4.2.1.2.1. Property `outputs`

4.2.1.2.2. Property `dynamicOutputs`

5. Property `system`

6. Property `builder`

7. Property `args`

8. Property `env`

8.1. Property `additionalProperties`

9. Property `structuredAttrs`