Dynamic values

Every dynamic value Echolot has, with its arguments and an example, grouped as the {{ list groups them.

A dynamic value is a function inside {{ }}: {{$uuid}}, {{$base64('heidi:alpenglow')}}, {{$responseJSONPath('auth/sign-in', '$.access_token')}}. Echolot works it out when the request is sent. Dynamic values work wherever variables do: the URL, headers, bodies, auth fields, messages and settings. For how to pick and edit them in the app, see dynamic values.

Writing them

A dynamic value starts with $: {{$timestamp}}. Without arguments the parentheses are optional.
Arguments go in parentheses, separated by commas: text in quotes ('…' or "…"), numbers, variable names without quotes, or other dynamic values.
Text arguments can hold tokens of their own: {{$base64('{{email}}:{{password}}')}}. }} inside quotes doesn't end the token.
Anything that doesn't parse stays as you wrote it and is reported, so a stray {{ never breaks a request.

{{$sha256('{{body}}', 'base64')}}
{{$date('yyyy-MM-dd', -86400, 'Europe/Zurich')}}
{{$hmacSha256(apiSecret, $timestamp)}}

Responses

These read the latest response of another saved request, given by its path (folder/request, as in auth/sign-in). Every one takes an optional last argument that says whether that request is sent first:

Last argument	Means
`'if-missing'` (default)	Send it first when it has no response yet.
`'fresh'`	Send it first every time; in a run, once per run.
`'latest'`	Never send it; use the latest response.

Value	Arguments	What it gives
`$responseJSONPath`	Request, JSONPath	A value from the response body, chosen with JSONPath. `{{$responseJSONPath('auth/sign-in', '$.access_token')}}`
`$responseKeyPath`	Request, key path	A value chosen with a key path such as `data.items.0.id`. `{{$responseKeyPath('orders/list-orders', 'items.0.id')}}`
`$responseJq`	Request, jq filter	What a jq filter makes of the body; several results come one per line. `{{$responseJq('catalog/list-products', '.items[0].sku')}}`
`$responseXPath`	Request, XPath	A value from an XML response. `{{$responseXPath('echo/xml', '/catalog/product[1]/@sku')}}`
`$responseRegex`	Request, pattern	The first match of a regular expression in the body: its first group if it has one. `{{$responseRegex('echo/html', '<title>(\\w+)</title>')}}`
`$responseHeader`	Request, header	A response header. `{{$responseHeader('orders/create-order', 'Location')}}`
`$responseCookie`	Request, cookie	The value of a cookie the response set. `{{$responseCookie('echo/set-cookie', 'flavour')}}`
`$responseStatus`	Request	The status code. `{{$responseStatus('auth/sign-in')}}`
`$responseBody`	Request	The whole body, as text. `{{$responseBody('auth/who-am-i')}}`
`$responseBodyLength`	Request	The body's size in bytes. `{{$responseBodyLength('catalog/export')}}`
`$response`	Request, query	Any of the above by the query's form: a JSONPath (`$.token`), an XPath (`/a/b`, or `xpath:…`), `regex:…`, `jq:…`, `keypath:…`, `header:Name` or `cookie:Name`. `{{$response('auth/sign-in', 'header:Content-Type')}}`

For example, Who am I could take its token straight from Sign in, sending it first if needed:

Authorization: Bearer {{$responseJSONPath('auth/sign-in', '$.access_token')}}

A request that reads another one's response in a circle is refused with the circle named. Response captures are the other way to carry values between requests.

Requests

These read a request as it would be sent, resolved. The first argument is a saved request's path, or empty ('') for the request being sent.

Value	Arguments	What it gives
`$requestURL`	Request	Its URL, resolved. `{{$requestURL('')}}`
`$requestMethod`	Request	Its method. `{{$requestMethod('')}}`
`$requestHeader`	Request, header	A header, resolved, including what its auth adds. `{{$requestHeader('', 'Content-Type')}}`
`$requestQuery`	Request, parameter	A query parameter of its URL, decoded. `{{$requestQuery('', 'page')}}`
`$requestBody`	Request	Its body, resolved, as text. `{{$requestBody('')}}`
`$requestJSONPath`	Request, JSONPath	A value from its JSON body. `{{$requestJSONPath('orders/create-order', '$.lines[0].sku')}}`
`$requestJq`	Request, jq filter	What a jq filter makes of its JSON body. `{{$requestJq('', '.lines[0].quantity')}}`
`$requestVariable`	Request, variable	A variable as that request sees it. `{{$requestVariable('auth/sign-in', 'email')}}`

Signing a request with what it sends is the usual use:

X-Signature: {{$hmacSha256(apiSecret, $requestBody(''))}}

Encoding

Value	Arguments	What it gives
`$base64`	Text	The text as Base64. `{{$base64('heidi:alpenglow')}}`
`$base64Decode`	Base64	Base64 or Base64URL decoded to text. `{{$base64Decode('aGVpZGk=')}}`
`$base64Url`	Text	The text as Base64URL, without padding. `{{$base64Url('{"alg":"none"}')}}`
`$urlEncode`	Text	The text percent-encoded for a URL component. `{{$urlEncode('ultralight tent')}}`
`$urlDecode`	Text	Percent-encoded text decoded; `+` stays `+`. `{{$urlDecode('ultralight%20tent')}}`
`$hex`	Text	The text's UTF-8 bytes in hex. `{{$hex('Grüezi')}}`
`$hexDecode`	Hex	Hex decoded to text. `{{$hexDecode('6869')}}`
`$jsonEscape`	Text	The text escaped to go inside a JSON string, without the quotes. `{{$jsonEscape(note)}}`
`$newline`	none	A line feed (`\n`).
`$cr`	none	A carriage return (`\r`).
`$crlf`	none	A carriage return and line feed (`\r\n`).
`$tab`	none	A tab.
`$unescape`	Sequence	Text with escape sequences turned into characters: `\n`, `\r`, `\t`, `\0`, `\\`, `\xHH`, `\uHHHH`. `{{$unescape('café')}}`
`$basicAuth`	User, password	An `Authorization` value for HTTP Basic: `Basic` and Base64 of `user:password`. `{{$basicAuth(email, password)}}`
`$jwt`	Payload, secret, algorithm (optional)	A JWT of the JSON payload, signed with the secret: `HS256` unless you choose `HS384` or `HS512`. `{{$jwt('{"sub": "heidi"}', jwtSecret)}}`

Hashes and signatures

Each hash takes the text and, optionally, the output: 'hex' (the default), 'base64' or 'base64url'. Each HMAC takes the key, the message and, optionally, the output.

Value	Arguments	What it gives
`$md5`	Text, output	The MD5 of the text. `{{$md5('alpenglow')}}`
`$sha1`	Text, output	The SHA-1. `{{$sha1('alpenglow')}}`
`$sha224`	Text, output	The SHA-224.
`$sha256`	Text, output	The SHA-256. `{{$sha256($requestBody(''), 'base64')}}`
`$sha384`	Text, output	The SHA-384.
`$sha512`	Text, output	The SHA-512.
`$hmacMd5`	Key, message, output	The HMAC-MD5 of the message with the key.
`$hmacSha1`	Key, message, output	The HMAC-SHA1.
`$hmacSha224`	Key, message, output	The HMAC-SHA224.
`$hmacSha256`	Key, message, output	The HMAC-SHA256. `{{$hmacSha256(apiSecret, $timestamp)}}`
`$hmacSha384`	Key, message, output	The HMAC-SHA384.
`$hmacSha512`	Key, message, output	The HMAC-SHA512.

Time

All of these are the moment the request is sent.

Value	Arguments	What it gives
`$timestamp`	none	Unix time in seconds: `1793525000`.
`$timestampMs`	none	Unix time in milliseconds: `1793525000123`.
`$isoTimestamp`	none	ISO 8601 in UTC, with milliseconds: `2026-11-01T09:30:00.123Z`.
`$httpDate`	none	An HTTP date, for `Date` or `If-Modified-Since`: `Sun, 01 Nov 2026 09:30:00 GMT`.
`$date`	Format, offset in seconds (optional), time zone (optional)	The time in a Unicode date pattern, moved by the offset, in the time zone (UTC unless given). `{{$date('yyyy-MM-dd')}}`, `{{$date('yyyy-MM-dd HH:mm', 3600, 'Europe/Zurich')}}`

Random

A new value on every send.

Value	Arguments	What it gives
`$uuid`	none	A random UUID, in lower case. Also `$guid` and `$randomUUID`. `{{$uuid}}`
`$randomInt`	Minimum, maximum	A whole number between the two, both included. One argument is the maximum, from 0; none is 0 to 1000. `{{$randomInt(1, 5)}}`
`$randomString`	Length, characters (optional)	Random characters, 16 unless given (up to 4096): letters and digits, or the characters given. `{{$randomString(8, 'ABCDEF0123456789')}}`
`$randomHex`	Bytes	Random bytes in hex, 16 unless given (up to 2048); twice as many digits. `{{$randomHex(8)}}`

Alpenglow's Create order sends Idempotency-Key: {{$uuid}}, so every order it places is a new one.

Fake data

Made-up values for request bodies, test data and mock routes: names, addresses, companies, prices, dates, lorem ipsum and more, new on every send. The names are Postman's dynamic variables, so collections that use them send real values here. In the {{ list they are under Fake Data, by group.

Arguments are optional; numbers go from -10^15 to 10^15. Mock bodies can also use $uuid (as $randomUUID), $randomInt, $randomString, $randomHex, $timestamp, $timestampMs and $isoTimestamp from Random and Time. From Terminal, echolot fake fills a template with them.

Common

Value	Arguments	What it gives
`$randomFloat`	Minimum, Maximum, Decimals	A decimal number between the bounds (0 to 1000), with 2 decimals unless told otherwise.
`$randomDigits`	Length	A string of random digits, 6 unless a length is given.
`$randomBoolean`	none	true or false.
`$randomElement`	Choices	One of the arguments, chosen at random: $randomElement(active, paused, closed).
`$randomAlphaNumeric`	none	One letter or digit.
`$randomColor`	none	A colour name: teal.
`$randomHexColor`	none	A colour in hex: #3f8acb.
`$randomAbbreviation`	none	A technical abbreviation: SQL.

Names and jobs

Value	Arguments	What it gives
`$randomFirstName`	none	A first name: Amelia.
`$randomLastName`	none	A last name: Okafor.
`$randomFullName`	none	A first and last name: Amelia Okafor.
`$randomNamePrefix`	none	Mr., Ms., Dr.…
`$randomNameSuffix`	none	Jr., PhD…
`$randomJobArea`	none	Mobility, Security…
`$randomJobDescriptor`	none	Lead, Senior…
`$randomJobTitle`	none	Senior Security Engineer.
`$randomJobType`	none	Engineer, Designer…

Internet

Value	Arguments	What it gives
`$randomEmail`	none	An email address: amelia.okafor@gmail.com.
`$randomExampleEmail`	none	An email address at example.com, example.net or example.org.
`$randomUserName`	none	A user name: amelia_okafor42.
`$randomPassword`	none	15 random letters and digits.
`$randomUrl`	none	https://northwind.io
`$randomDomainName`	none	northwind.io
`$randomDomainSuffix`	none	com, io, dev…
`$randomDomainWord`	none	northwind
`$randomIP`	none	An IPv4 address: 192.168.14.7.
`$randomIPV6`	none	An IPv6 address.
`$randomMACAddress`	none	A MAC address: 3a:f1:0c:5e:92:b4.
`$randomProtocol`	none	http or https.
`$randomSemver`	none	A semantic version: 2.14.3.
`$randomLocale`	none	A locale: de_CH.
`$randomUserAgent`	none	A browser's User-Agent.

Addresses and places

Value	Arguments	What it gives
`$randomStreetName`	none	Maple Avenue
`$randomStreetAddress`	none	42 Maple Avenue
`$randomCity`	none	Lisbon
`$randomZipCode`	none	A five-digit postal code. Also `$randomZip`.
`$randomCountry`	none	Portugal
`$randomCountryCode`	none	An ISO 3166 country code: PT.
`$randomLatitude`	none	A latitude: 38.7223.
`$randomLongitude`	none	A longitude: -9.1393.

Phone

Value	Arguments	What it gives
`$randomPhoneNumber`	none	A phone number: 555-201-4417.
`$randomPhoneNumberExt`	none	A phone number with a country code: +44 555-201-4417.

Companies

Value	Arguments	What it gives
`$randomCompanyName`	none	Northwind Labs
`$randomCompanySuffix`	none	Inc, LLC, GmbH…
`$randomBs`	none	streamline seamless platforms
`$randomBsAdjective`	none	seamless
`$randomBsBuzz`	none	streamline
`$randomBsNoun`	none	platforms
`$randomCatchPhrase`	none	Adaptive real-time framework
`$randomCatchPhraseAdjective`	none	Adaptive
`$randomCatchPhraseDescriptor`	none	real-time
`$randomCatchPhraseNoun`	none	framework

Finance

Value	Arguments	What it gives
`$randomPrice`	Minimum, Maximum	A price with two decimals, 1 to 1000 unless bounds are given.
`$randomCurrencyCode`	none	EUR
`$randomCurrencyName`	none	Euro
`$randomCurrencySymbol`	none	€
`$randomBankAccount`	none	An 8-digit account number.
`$randomBankAccountName`	none	Savings Account
`$randomBankAccountIban`	none	An IBAN with valid check digits.
`$randomBankAccountBic`	none	A BIC (SWIFT code).
`$randomCreditCardMask`	none	The last four digits of a card.
`$randomTransactionType`	none	deposit, payment, refund…
`$randomBitcoin`	none	A made-up bitcoin address.

Shops and products

Value	Arguments	What it gives
`$randomProduct`	none	Chair
`$randomProductName`	none	Ergonomic Wooden Chair
`$randomProductAdjective`	none	Ergonomic
`$randomProductMaterial`	none	Wooden
`$randomDepartment`	none	Garden

Dates

Value	Arguments	What it gives
`$randomDatePast`	none	A moment in the past year, ISO 8601.
`$randomDateFuture`	none	A moment in the next year, ISO 8601.
`$randomDateRecent`	none	A moment in the past two days, ISO 8601.
`$randomDate`	none	A day in the past year: 2026-03-14.
`$randomWeekday`	none	Tuesday
`$randomMonth`	none	March

Words

Value	Arguments	What it gives
`$randomWord`	none	A word.
`$randomWords`	Count	A few words, 3 unless a count is given.
`$randomNoun`	none	router
`$randomVerb`	none	compile
`$randomIngverb`	none	compiling
`$randomAdjective`	none	wireless
`$randomPhrase`	none	A short phrase made of the words above.

Lorem ipsum

Value	Arguments	What it gives
`$randomLoremWord`	none	dolor
`$randomLoremWords`	Count	Lorem words, 3 unless a count is given.
`$randomLoremSentence`	none	One sentence.
`$randomLoremSentences`	Count	A few sentences, 2 to 6 unless a count is given.
`$randomLoremParagraph`	none	One paragraph.
`$randomLoremParagraphs`	Count	Paragraphs, 3 unless a count is given.
`$randomLoremText`	none	A sentence or a few.
`$randomLoremSlug`	none	dolor-sit-amet
`$randomLoremLines`	none	A few sentences, one per line.

Files

Value	Arguments	What it gives
`$randomFileName`	none	router_matrix.pdf
`$randomFileType`	none	image, text, video…
`$randomFileExt`	none	pdf
`$randomCommonFileName`	none	A file name with a common extension.
`$randomCommonFileType`	none	image, video, text…
`$randomCommonFileExt`	none	png
`$randomFilePath`	none	/var/reports/router_matrix.pdf
`$randomDirectoryPath`	none	/var/reports
`$randomMimeType`	none	application/pdf

Images

Value	Arguments	What it gives
`$randomAvatarImage`	none	The address of an avatar picture.
`$randomImageUrl`	none	The address of a 640×480 picture.
`$randomAbstractImage`	none	The address of a 640×480 picture on the topic abstract. The other topics: `$randomAnimalsImage`, `$randomBusinessImage`, `$randomCatsImage`, `$randomCityImage`, `$randomFoodImage`, `$randomNightlifeImage`, `$randomFashionImage`, `$randomPeopleImage`, `$randomNatureImage`, `$randomSportsImage`, `$randomTransportImage`.
`$randomImageDataUri`	none	A small SVG picture as a data: URI.

Databases

Value	Arguments	What it gives
`$randomDatabaseColumn`	none	createdAt
`$randomDatabaseType`	none	varchar
`$randomDatabaseCollation`	none	utf8mb4_unicode_ci
`$randomDatabaseEngine`	none	InnoDB

Text

Value	Arguments	What it gives
`$lowercase`	Text	The text in lower case. `{{$lowercase(email)}}`
`$uppercase`	Text	The text in upper case. `{{$uppercase(productId)}}`
`$trim`	Text	The text without spaces and line breaks at either end. `{{$trim($responseBody('auth/who-am-i'))}}`

Files and the system

Value	Arguments	What it gives
`$file`	Path	The contents of a file: a path relative to the workspace, or an absolute one. `{{$file('fixtures/order.json')}}`
`$env`	Name	An environment variable of the Echolot process. `{{$env('HOME')}}`

Dynamic values and agents

When an AI agent sends a request (through Echolot's MCP server or the Assistant), $env gives nothing, and $file reads only files inside the workspace. Secret values never reach the agent. See agents.

Dynamic values

Writing themCopy Anchor Link

ResponsesCopy Anchor Link

RequestsCopy Anchor Link

EncodingCopy Anchor Link

Hashes and signaturesCopy Anchor Link

TimeCopy Anchor Link

RandomCopy Anchor Link

Fake dataCopy Anchor Link

CommonCopy Anchor Link

Names and jobsCopy Anchor Link

InternetCopy Anchor Link

Addresses and placesCopy Anchor Link

PhoneCopy Anchor Link

CompaniesCopy Anchor Link

FinanceCopy Anchor Link

Shops and productsCopy Anchor Link

DatesCopy Anchor Link

WordsCopy Anchor Link

Lorem ipsumCopy Anchor Link

FilesCopy Anchor Link

ImagesCopy Anchor Link

DatabasesCopy Anchor Link

TextCopy Anchor Link

Files and the systemCopy Anchor Link

Dynamic values and agentsCopy Anchor Link

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