Template Function Reference

Template Function Reference

Templates use Go text/template with two layers of functions: a sprig subset for general-purpose string/date/math operations, and domain-specific helpers for provider-aware cross-references. This page documents every available function, its signature, and examples.

Function availability by notifier

Not all notifiers get the same functions. Before using a function, check whether your target notifier supports it.

Function category	SCM comments	Grafana	Jira	Accumulator	Slack	Teams	Discord	Email
Sprig subset	✅	✅	✅	✅	❌	❌	❌	❌
Domain helpers	✅	✅	✅	✅	❌	❌	❌	❌

Slack, Teams, Discord, and Email use plain Go templates. Use printf for formatting, if/range/eq for logic, and manual string construction for everything else.

Domain helpers

These functions are defined by the relay and take precedence over any sprig equivalents. They produce provider-aware output.

IssueRef

IssueRef(provider string, issueNum int, owner string, repo string) string

Returns the provider-specific markdown syntax for referencing an issue.

Provider	Same-repo output	Cross-repo output
github	#42	owner/repo#42
gitlab	#42	owner/repo#42
gitea	#42	owner/repo#42
bitbucket_cloud	#42	owner/repo#42
bitbucket_server	#42	owner/repo#42
azure_devops	#42	#42 (no cross-repo)
sourcehut	"" (not supported)	""

Examples:

{{ IssueRef .Provider 42 "" "" }}

Renders #42 on most providers, empty string on SourceHut.

{{ IssueRef .Provider 42 "acme" "backend" }}

Renders acme/backend#42 on GitHub/GitLab/Gitea/Bitbucket, #42 on Azure DevOps.

Guard usage (safe to call even when IssueNumber is nil):

{{ if .IssueNumber }}Related: {{ IssueRef .Provider .IssueNumber .Repo.Owner .Repo.Name }}{{ end }}

PRRef

PRRef(provider string, prNum int, owner string, repo string) string

Returns the provider-specific syntax for referencing a pull request or merge request.

Provider	Same-repo output	Cross-repo output
github	#42	owner/repo#42
gitlab	!42	owner/repo!42
gitea	#42	owner/repo#42
bitbucket_cloud	#42	owner/repo#42
bitbucket_server	#42	owner/repo#42
azure_devops	#42	#42 (no cross-repo)
sourcehut	"" (not supported)	""

Note the GitLab difference: merge requests use ! instead of #.

Examples:

{{ PRRef .Provider 123 "" "" }}

Renders #123 on most providers, !123 on GitLab.

{{ PRRef .Provider 123 "acme" "frontend" }}

Renders acme/frontend!123 on GitLab, acme/frontend#123 on GitHub/Gitea/Bitbucket.

UserMention

UserMention(provider string, username string) string

Returns the provider-specific syntax for mentioning a user. All supported providers use @username.

Provider	Output
github	@alice
gitlab	@alice
gitea	@alice
bitbucket_cloud	@alice
bitbucket_server	@alice
azure_devops	@alice
sourcehut	alice (no mention syntax)

Example:

Assigned to {{ UserMention .Provider "alice" }}

Truncate

Truncate(s string, limit int) string

Rune-aware truncation with ... suffix. Counts runes (Unicode characters), not bytes, so multi-byte characters like emoji don't cause issues.

• If limit is 0, returns the original string (no limit).
• If the string is shorter than the limit, returns it unchanged.
• If truncated, appends ... (consuming 3 characters of the limit).
• If limit is less than 3, truncates without the ellipsis.

Examples:

{{ Truncate .Description 200 }}

If Description is 250 characters, returns the first 197 characters followed by ....

{{ Truncate .Description 300 }}

If Description is 250 characters, returns the full string unchanged.

{{ Truncate "short" 200 }}

Returns short (already under the limit).

Sprig functions (safe subset)

The relay starts with sprig's full TxtFuncMap and removes dangerous functions. Here are the most commonly used categories.

Removed functions (security)

These functions are stripped from the template environment:

Function	Why removed
env, expandenv, expand	Prevents environment variable exfiltration
base64Encode, base64Decode	Prevents cryptographic misuse
genPrivateKey, genCA, genSelfSignedCert	Prevents key generation in templates

String functions

Function	Signature	Example	Output
upper	upper(string)	{{ .State | upper }}	SUCCESS
lower	lower(string)	{{ .State | lower }}	success
title	title(string)	{{ .State | title }}	Success
trim	trim(string)	{{ .Description | trim }}	trimmed
trimAll	trimAll(string)	{{ " hello " | trimAll }}	hello
trimPrefix	trimPrefix(prefix, string)	{{ "build-123" | trimPrefix "build-" }}	123
trimSuffix	trimSuffix(suffix, string)	{{ "123-test" | trimSuffix "-test" }}	123
replace	replace(old, new, string)	{{ "hello world" | replace "world" "relay" }}	hello relay
trunc	trunc(n, string)	{{ .CommitSHA | trunc 8 }}	first 8 characters
contains	contains(substr, string)	{{ contains "fail" .Description }}	bool
hasPrefix	hasPrefix(prefix, string)	{{ hasPrefix "tekton-" .RunName }}	bool
hasSuffix	hasSuffix(suffix, string)	{{ hasSuffix "-run" .RunName }}	bool
repeat	repeat(count, string)	{{ repeat 3 "-" }}	---
quote	quote(string)	{{ .RunName | quote }}	"my-run"
squote	squote(string)	{{ .RunName | squote }}	'my-run'
cat	cat(args...)	{{ cat "hello" "world" }}	hello world
split	split(sep, string)	{{ index (split ":" "a:b:c") "_1" }}	b
splitList	splitList(sep, string)	{{ splitList "/" "a/b/c" }}	[a b c]
join	join(sep, list)	{{ join "," (list "a" "b") }}	a,b
regexReplaceAll	regexReplaceAll(pattern, string, repl)	See below	matched pattern replaced

Truncation in non-sprig notifiers: For Slack, Teams, Discord, and Email, use printf "%.200s" .Description instead of Truncate. The printf function is always available.

Math functions

Function	Signature	Example	Output
add	add(a, b)	{{ add 1 2 }}	3
sub	sub(a, b)	{{ sub 10 3 }}	7
mul	mul(a, b)	{{ mul 3 4 }}	12
div	div(a, b)	{{ div 10 3 }}	3
mod	mod(a, b)	{{ mod 10 3 }}	1
max	max(a, b)	{{ max 5 3 }}	5
min	min(a, b)	{{ min 5 3 }}	3

Date/time functions

Function	Signature	Example	Output
now	now()	{{ now }}	current time
date	date(fmt, time)	{{ date "2006-01-02" .StartedAt }}	2024-01-15
dateModify	dateModify(mod, time)	{{ dateModify "-24h" now }}	24h ago
ago	ago(time)	{{ ago .StartedAt }}	5m30s
duration	duration(seconds)	{{ duration 90 }}	1h30m0s
unixEpoch	unixEpoch(time)	{{ unixEpoch .StartedAt }}	unix timestamp

Duration calculation (common pattern):

{{- if and (not .StartedAt.IsZero) (not .FinishedAt.IsZero) -}}
Duration: {{ regexReplaceAll "[.][0-9]+s" (toString (.FinishedAt.Sub .StartedAt)) "s" }}
{{- end }}

Collection functions

Function	Signature	Example	Output
list	list(items...)	{{ list "a" "b" }}	[a b]
first	first(n, list)	{{ first 2 (list 1 2 3) }}	[1 2]
last	last(n, list)	{{ last 2 (list 1 2 3) }}	[2 3]
reverse	reverse(list)	{{ reverse (list 1 2 3) }}	[3 2 1]
sortAlpha	sortAlpha(list)	{{ sortAlpha (list "c" "a" "b") }}	[a b c]
uniq	uniq(list)	{{ uniq (list 1 1 2 3) }}	[1 2 3]
has	has(item, list)	{{ has "a" (list "a" "b") }}	true
append	append(list, items...)	{{ append (list 1 2) 3 }}	[1 2 3]
concat	concat(lists...)	{{ concat (list 1) (list 2 3) }}	[1 2 3]

Logic functions

Function	Signature	Example	Output
ternary	ternary(trueVal, falseVal, condition)	{{ ternary "✅" "❌" (eq .State "success") }}	✅ or ❌
default	default(defaultVal, val)	{{ .PipelineName | default .RunName }}	falls back to RunName
empty	empty(val)	{{ if empty .Description }}no desc{{ end }}	checks emptiness
coalesce	coalesce(vals...)	{{ coalesce .Description "N/A" }}	first non-empty
toJson	toJson(val)	{{ . | toJson }}	JSON string

Type conversion

Function	Signature	Example	Output
toString	toString(val)	{{ toString 42 }}	"42"
toInt	toInt(val)	{{ "42" | toInt }}	42
toBool	toBool(val)	{{ toBool "true" }}	true

String building

Function	Signature	Example	Output
printf	printf(fmt, args...)	{{ printf "%.8s" .CommitSHA }}	first 8 chars
println	println(args...)	{{ println "hello" "world" }}	hello world\n
indent	indent(spaces, string)	{{ indent 2 "line1\nline2" }}	indented
nindent	nindent(spaces, string)	{{ nindent 2 "line1" }}	newline + indented

Common patterns

Conditional content with default

{{ .PipelineName | default .RunName }}

State-based emoji (non-sprig notifiers)

{{- if eq .State "success" }}✅
{{- else if eq .State "failure" }}❌
{{- else if eq .State "error" }}⚠️
{{- else if eq .State "canceled" }}🚫
{{- else }}⏳
{{- end }}

Truncated description with fallback

{{ Truncate (.Description | default "No description available") 300 }}

Duration formatting

{{- if and (not .StartedAt.IsZero) (not .FinishedAt.IsZero) }}
Duration: {{ regexReplaceAll "[.][0-9]+s" (toString (.FinishedAt.Sub .StartedAt)) "s" }}
{{- end }}

Results table (sprig only)

{{- if .Results }}
<details><summary>Results ({{ len .Results }})</summary>

| Name | Value |
|---|---|
{{- range .Results }}
| {{ .Name }} | {{ Truncate .Value 120 }} |
{{- end }}

</details>
{{- end }}

Results list (non-sprig notifiers)

{{- if .Results }}
Results:
{{- range .Results }}
- {{ .Name }}: {{ printf "%.120s" .Value }}
{{- end }}
{{- end }}