Generate Fake Data For Mock API Response

Imagine that you want to prototype an app with realistic-looking data, but the backend APIs are not there yet. That's where Beeceptor comes in. With Beeceptor, you have access to a powerful template engine that uses Handlebars' syntax. You can easily generate fake data that looks and feels realistic, without the hassle of dealing with messy code.

Fake data helpers

Beeceptor uses popular Faker's comparable syntax. It becomes a breeze to generate small/large data using a mocked response template. You can use pretty much all the attributes from Faker namespaces.

Enabling faker template

By default, template engine is off. You need to explicitly mark a rule to enable usage of Handlebars template to generate fake data.

The faker Syntax

Beeceptor defines faker as a Handlebars template helper.

Faker attributes are grouped into namespaces. E.g. datatype, address, company, etc. To generate faked value for given attribute, prefix the attribute with its namespace. Refer below examples and values generated.

Syntax: {{faker 'namespace.attribute'}}

Sample Syntax	Generated value
{{faker 'random.uuid'}}	52375efe-cf9e-44f5-adb2-65c1631bfcea
{{faker 'address.country'}}	Spain
{{faker 'finance.currencyCode'}}	USD
{{faker 'hacker.phrase'}}	The AI hard drive is down, index the 1080p panel so we can override the COM firewall!
{{faker 'lorem.paragraph'}}	Omnis perspiciatis provident error. Est possimus voluptates. Illo nam et excepturi blanditiis quae rerum et amet accusantium. Mollitia temporibus temporibus ea fugiat quia in possimus et. Ut provident est debitis perspiciatis ipsa non mollitia magnam quis. Et quod dolorum et non

Refer the section below to view complete list of supported attributes.

Example using mocking template

You can mix and match any of the Faker attributes to build a rich response. Consider the following example for GET /users API or model.

Mocking Template: A mocking template to build user objects.

[
    { 
        "id" : "{{faker 'random.uuid'}}",
        "name": "{{faker 'name.firstName'}} {{faker 'name.lastName'}}" ,
        "address": "{{faker 'address.streetAddress'}}",
        "country": "{{faker 'address.country'}}",
        "phone": "{{faker 'phone.phoneNumber'}}",
        "profileImage": "{{faker 'image.image'}}",
    },
    { 
        "id" : "{{faker 'random.uuid'}}",
        "name": "{{faker 'name.firstName'}} {{faker 'name.lastName'}}" ,
        "address": "{{faker 'address.streetAddress'}}",
        "country": "{{faker 'address.country'}}",
        "phone": "{{faker 'phone.phoneNumber'}}",
        "profileImage": "{{faker 'image.image'}}",
    }
]

Response: This will generate below output:

[
    { 
        "id" : "cbe55c5d-36fa-4f05-9557-fcd4966187f4",
        "name": "Dillon Davis" ,
        "address": "613 Dickinson Run",
        "country": "Tanzania",
        "phone": "886.282.3509 x0831",
        "profileImage": "http://placeimg.com/640/480/business",
    },
    { 
        "id" : "36df51a8-8d4c-4d70-8818-d77b9f6bf215",
        "name": "Dannie Hackett" ,
        "address": "8449 Brenna Alley",
        "country": "Central African Republic",
        "phone": "(786) 895-4923",
        "profileImage": "http://placeimg.com/640/480/business",
    }
]

Advance use-cases - Parameterized examples

You can pass arguments to the faker syntax and generate even more specific and tailored fake data. Here are a few examples:

1. Generate a date between given two dates: {{faker 'date.between' '2022-05-01' '2022-05-15'}}
2. Generate a past date in the last 5 years: {{faker 'date.past' '5'}}
3. Generate a female first name: {{faker 'name.firstName' 'female'}}
4. Generate a 10 digit alphanumeric {{faker 'random.alphaNumeric' '10' }}
5. Generate ten lines of lorem {{faker 'lorem.lines' '10' }}
6. Generate a paragraph {{faker 'lorem.paragraph' }}, or a paragraph with five sentences {{faker 'lorem.paragraph' '5' }}
7. Generate a file name {{faker 'system.fileName'}}
8. Generates a random ethereum Address {{faker 'finance.ethereumAddress'}}
9. Generate a short product name {{faker 'commerce.productName'}}
10. Generate a random password {{faker 'internet.password'}}
11. Generate a random number between {{faker 'mersenne.rand' '500' '1000'}}
12. Generate a random domain name {{faker 'internet.domainName'}}

You can checkout Fake JSON API as a reference when building the template. This is a pre-built mock server provided by Beeceptor for most common use-cases.

Supported classes

Datatypes

Use the following constructs to generate random datatype values, string, uuid, etc.

datatype.number
datatype.float
datatype.uuid
datatype.boolean
datatype.string
datatype.hexaDecimal

Random

Use the following constructs to generate some random combinations.

random.word
random.words
random.image
random.locale
random.alphaNumeric

Lorem

Some blah blah... text and paragraphs.

lorem.word
lorem.words
lorem.sentence
lorem.slug
lorem.sentences
lorem.paragraph
lorem.paragraphs
lorem.text
lorem.lines

Person Names

Generate first/last name, titles, job type, etc.

name.firstName
name.lastName
name.findName
name.jobTitle
name.prefix
name.suffix
name.title
name.jobDescriptor
name.jobArea
name.jobType

Address

address.zipCode
address.city
address.cityPrefix
address.citySuffix
address.streetName
address.streetAddress
address.streetSuffix
address.streetPrefix
address.secondaryAddress
address.county
address.country
address.countryCode
address.state
address.stateAbbr
address.latitude
address.longitude

Phone Numbers

phone.phoneNumber
phone.phoneNumberFormat
phone.phoneFormats

E-commerce

Some realistic product names.

commerce.color
commerce.department
commerce.productName
commerce.price
commerce.productAdjective
commerce.productMaterial
commerce.product

Company

company.suffixes
company.companyName
company.companySuffix
company.catchPhrase
company.bs
company.catchPhraseAdjective
company.catchPhraseDescriptor
company.catchPhraseNoun
company.bsAdjective
company.bsBuzz
company.bsNoun

Finance

finance.account
finance.accountName
finance.mask
finance.amount
finance.transactionType
finance.currencyCode
finance.currencyName
finance.currencySymbol
finance.bitcoinAddress
finance.iban
finance.bic

Date

date.past
date.future
date.between
date.recent
date.month
date.weekday

Online Forum

hacker.abbreviation
hacker.adjective
hacker.noun
hacker.verb
hacker.ingverb
hacker.phrase

Images

Generates links to images for the following categories.

E.g. The image.animals syntax will generate a link to http://placeimg.com/640/480/animals. The image.image syntax will generate a link to a random image for any of the below categories.

image.image
image.avatar
image.imageUrl
image.abstract
image.animals
image.business
image.cats
image.city
image.food
image.nightlife
image.fashion
image.people
image.nature
image.sports
image.technics
image.transport
image.dataUri

Internet

internet.avatar
internet.email
internet.exampleEmail
internet.userName
internet.protocol
internet.url
internet.domainName
internet.domainSuffix
internet.domainWord
internet.ip
internet.ipv6
internet.userAgent
internet.color
internet.mac
internet.password

Database

database.column
database.type
database.collation
database.engine

Git

git.branch
git.commitEntry
git.commitMessage
git.commitSha
git.shortSha

System

system.fileName
system.commonFileName
system.mimeType
system.commonFileType
system.commonFileExt
system.fileType
system.fileExt
system.directoryPath
system.filePath
system.semver

Troubleshooting

When there are syntax errors in defining templates, Beeceptor tries to recover safely and attempts to generate the mocked response. However, there can be unrecoverable errors.

1. If the faker syntax has any issue, you shall get Faker Attribute Error: Missing or wrong syntax in the response.
2. If there is an unrecoverable error, a response with 561 HTTP status code is returned. In such cases, you should review the template's syntax and correct it.