Workflow DSL Reference

Complete reference for the CNCF Serverless Workflow DSL 1.0 as implemented in Triggerfish's workflow engine. For usage guide and examples, see Workflows.

Document Structure

Every workflow YAML must have a top-level document field and a do block.

document:
  dsl: "1.0"
  namespace: my-namespace
  name: my-workflow
  version: "1.0.0"            # optional
  description: "What it does"  # optional
classification_ceiling: INTERNAL  # optional
input:                            # optional
  from: "${ . }"
output:                           # optional
  from:
    result: "${ .final_step }"
timeout:                          # optional
  after: PT5M
do:
  - task_name:
      # task definition

Document Metadata

Field	Type	Required	Description
dsl	string	yes	DSL version. Must be "1.0"
namespace	string	yes	Logical grouping (e.g., ops, reports)
name	string	yes	Unique workflow name within the namespace
version	string	no	Semantic version string
description	string	no	Human-readable description

Top-Level Fields

Field	Type	Required	Description
document	object	yes	Document metadata (see above)
do	array	yes	Ordered list of task entries
classification_ceiling	string	no	Maximum allowed session taint during execution
input	transform	no	Transform applied to workflow input
output	transform	no	Transform applied to workflow output
timeout	object	no	Workflow-level timeout (after: <ISO 8601>)
metadata	object	no	Arbitrary key-value metadata

---

Task Entry Format

Each entry in the do block is a single-key object. The key is the task name, the value is the task definition.

do:
  - my_task_name:
      call: http
      with:
        endpoint: "https://example.com"

Task names must be unique within the same do block. The task result is stored in the data context under the task name.

---

Common Task Fields

All task types share these optional fields:

Field	Type	Description
if	string	Expression condition. Task is skipped when falsy.
input	transform	Transform applied before task execution
output	transform	Transform applied after task execution
timeout	object	Task timeout: after: <ISO 8601 duration>
then	string	Flow directive: continue, end, or a task name
metadata	object	Arbitrary key-value metadata. When self-healing is enabled, requires description, expects, produces.

---

Self-Healing Configuration

The metadata.triggerfish.self_healing block enables an autonomous healing agent for the workflow. See Self-Healing for a full guide.

metadata:
  triggerfish:
    self_healing:
      enabled: true
      retry_budget: 3
      approval_required: true
      pause_on_intervention: blocking_only
      pause_timeout_seconds: 300
      pause_timeout_policy: escalate_and_halt
      notify_on: [intervention, escalation, approval_required]

Field	Type	Required	Default	Description
enabled	boolean	yes	—	Enable the healing agent
retry_budget	number	no	3	Max intervention attempts
approval_required	boolean	no	true	Require human approval for fixes
pause_on_intervention	string	no	"blocking_only"	always | never | blocking_only
pause_timeout_seconds	number	no	300	Seconds before timeout policy fires
pause_timeout_policy	string	no	"escalate_and_halt"	escalate_and_halt | escalate_and_skip | escalate_and_fail
notify_on	array	no	[]	intervention | escalation | approval_required

Step Metadata (Required When Self-Healing Enabled)

When self_healing.enabled is true, every task must include these metadata fields. The parser rejects workflows missing any of them.

Field	Type	Description
description	string	What the step does and why
expects	string	Input shape or preconditions needed
produces	string	Output shape generated

- fetch-invoices:
    call: http
    with:
      endpoint: "https://api.example.com/invoices"
    metadata:
      description: "Fetch open invoices from billing API"
      expects: "API available, returns JSON array"
      produces: "Array of {id, amount, status} objects"

---

Task Types

call

Dispatch to an HTTP endpoint or Triggerfish service.

Field	Type	Required	Description
call	string	yes	Call type (see dispatch table below)
with	object	no	Arguments passed to the target tool

- fetch:
    call: http
    with:
      endpoint: "https://api.example.com/data"
      method: GET

run

Execute a shell command, inline script, or sub-workflow. The run field must contain exactly one of shell, script, or workflow.

Shell:

Field	Type	Required	Description
run.shell.command	string	yes	Shell command to execute
run.shell.arguments	object	no	Named arguments
run.shell.environment	object	no	Environment variables

Script:

Field	Type	Required	Description
run.script.language	string	yes	Script language
run.script.code	string	yes	Inline script code
run.script.arguments	object	no	Named arguments

Sub-workflow:

Field	Type	Required	Description
run.workflow.name	string	yes	Name of the saved workflow
run.workflow.version	string	no	Version constraint
run.workflow.input	object	no	Input data for sub-workflow

set

Assign values to the data context.

Field	Type	Required	Description
set	object	yes	Key-value pairs to assign. Values can be expressions.

- prepare:
    set:
      full_name: "${ .first_name } ${ .last_name }"
      count: 0

switch

Conditional branching. The switch field is an array of case entries. Each case is a single-key object where the key is the case name.

Case field	Type	Required	Description
when	string	no	Expression condition. Omit for default case.
then	string	yes	Flow directive: continue, end, or task name

Cases are evaluated in order. The first case with a truthy when (or no when) is taken.

- route:
    switch:
      - high:
          when: "${ .priority > 7 }"
          then: alert_team
      - low:
          then: log_only

for

Iterate over a collection.

Field	Type	Required	Description
for.each	string	yes	Variable name for the current item
for.in	string	yes	Expression referencing the collection
for.at	string	no	Variable name for the current index
do	array	yes	Nested task list executed for each iteration

- process_all:
    for:
      each: item
      in: "${ .items }"
      at: idx
    do:
      - handle:
          call: triggerfish:llm
          with:
            task: "Process item ${ .idx }: ${ .item.name }"

raise

Halt the workflow with a structured error.

Field	Type	Required	Description
raise.error.status	number	yes	HTTP-style status code
raise.error.type	string	yes	Error type URI/string
raise.error.title	string	yes	Human-readable title
raise.error.detail	string	no	Detailed error message

- abort:
    raise:
      error:
        status: 422
        type: "validation-error"
        title: "Invalid input"
        detail: "Field 'email' is required"

emit

Record a workflow event. Events are stored in the run result.

Field	Type	Required	Description
emit.event.type	string	yes	Event type identifier
emit.event.source	string	no	Event source URI
emit.event.data	object	no	Event payload

- record:
    emit:
      event:
        type: "step.completed"
        source: "workflow/pipeline"
        data:
          step: "transform"
          duration_ms: 1200

wait

Pause execution for a duration.

Field	Type	Required	Description
wait	string	yes	ISO 8601 duration (e.g., PT5S)

Common durations: PT1S (1 second), PT30S (30 seconds), PT1M (1 minute), PT5M (5 minutes).

---

Call Dispatch Table

Maps the call field value to the Triggerfish tool that is actually invoked.

call value	Tool invoked	Required with: fields
http	web_fetch	endpoint or url; optional method, headers, body
triggerfish:llm	llm_task	prompt or task; optional tools, max_iterations
triggerfish:agent	subagent	prompt or task; optional tools, agent
triggerfish:memory	memory_*	operation (save/search/get/list/delete) + operation fields
triggerfish:web_search	web_search	query; optional max_results
triggerfish:web_fetch	web_fetch	url; optional method, headers, body
triggerfish:mcp	mcp__<server>__<tool>	server, tool; optional arguments
triggerfish:message	send_message	channel, text; optional recipient

Unsupported CNCF call types (grpc, openapi, asyncapi) return an error.

---

Expression Syntax

Expressions are delimited by ${ } and resolve against the workflow data context.

Dot-Path Resolution

Syntax	Description	Example result
${ . }	Entire data context	{...}
${ .key }	Top-level key	"value"
${ .a.b.c }	Nested key	"deep value"
${ .items[0] }	Array index	{...first item...}
${ .items[0].name }	Array index then key	"first"

The leading dot (or $.) anchors the path at the context root. Paths that resolve to undefined produce an empty string when interpolated, or undefined when used as a standalone value.

Operators

Type	Operators	Example
Comparison	==, !=, >, <, >=, <=	${ .count > 0 }
Arithmetic	+, -, *, /, %	${ .price * .quantity }

Comparison expressions return true or false. Arithmetic expressions return a number (undefined if either operand is not numeric or division by zero).

Literals

Type	Examples
String	"hello", 'hello'
Number	42, 3.14, -1
Boolean	true, false
Null	null

Interpolation Modes

Single expression (raw value): When the entire string is one ${ } expression, the raw typed value is returned (number, boolean, object, array).

count: "${ .items.length }"  # returns a number, not a string

Mixed / multiple expressions (string): When ${ } expressions are mixed with text or there are multiple expressions, the result is always a string.

message: "Found ${ .count } items in ${ .category }"  # returns a string

Truthiness

For if: conditions and switch when: expressions, values are evaluated using JavaScript-style truthiness:

Value	Truthy?
true	yes
Non-zero number	yes
Non-empty string	yes
Non-empty array	yes
Object	yes
false, 0, "", null, undefined, empty array	no

---

Input/Output Transforms

Transforms reshape data flowing into and out of tasks.

input

Applied before task execution. Replaces the task's view of the data context.

- step:
    call: http
    input:
      from: "${ .config }"       # task sees only the config object
    with:
      endpoint: "${ .api_url }"  # resolved against the config object

from as string: Expression that replaces the entire input context.

from as object: Maps new keys to expressions:

input:
  from:
    url: "${ .config.api_url }"
    token: "${ .secrets.api_token }"

output

Applied after task execution. Reshapes the result before storing it in the context under the task name.

- fetch:
    call: http
    output:
      from:
        items: "${ .fetch.data.results }"
        count: "${ .fetch.data.total }"

---

Flow Directives

The then field on any task controls execution flow after the task completes.

Value	Behavior
continue	Proceed to the next task in sequence (default)
end	Stop the workflow. Status: completed.
<task name>	Jump to the named task. The task must exist in the same do block.

Switch cases also use flow directives in their then field.

---

Classification Ceiling

Optional field restricting the maximum session taint during execution.

classification_ceiling: INTERNAL

Value	Meaning
PUBLIC	Workflow halts if any classified data is accessed
INTERNAL	Allows PUBLIC and INTERNAL data
CONFIDENTIAL	Allows up to CONFIDENTIAL data
RESTRICTED	Allows all classification levels
(omitted)	No ceiling enforced

The ceiling is checked before every task. If the session taint has escalated past the ceiling (e.g., because a prior task accessed classified data), the workflow halts with status failed and error Workflow classification ceiling breached.

---

Storage

Workflow Definitions

Stored with key prefix workflows:{name}. Each stored record contains:

Field	Type	Description
name	string	Workflow name
yaml	string	Raw YAML definition
classification	string	Classification level at time of save
savedAt	string	ISO 8601 timestamp
description	string	Optional description

Run History

Stored with key prefix workflow-runs:{runId}. Each run record contains:

Field	Type	Description
runId	string	UUID for this execution
workflowName	string	Name of the workflow that was executed
status	string	completed, failed, or cancelled
output	object	Final data context (internal keys filtered)
events	array	Events emitted during execution
error	string	Error message (if status is failed)
startedAt	string	ISO 8601 timestamp
completedAt	string	ISO 8601 timestamp
taskCount	number	Number of tasks in the workflow
classification	string	Session taint at completion

---

Limits

Limit	Value	Description
Sub-workflow max depth	5	Maximum nesting of run.workflow calls
Run history default limit	10	Default limit for workflow_history

---

Execution Statuses

Status	Description
pending	Workflow has been created but not started
running	Workflow is currently executing
completed	All tasks finished successfully (or then: end)
failed	A task failed, a raise was hit, or ceiling breached
cancelled	Execution was cancelled externally