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Formulas

website/docs/workflows/formulas.md

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Formulas

Formulas are declarative workflow templates.

Formula Format

Formulas can be written in TOML (preferred) or JSON:

TOML Format

toml
formula = "feature-workflow"
description = "Standard feature development workflow"
version = 1
type = "workflow"

[vars.feature_name]
description = "Name of the feature"
required = true

[[steps]]
id = "design"
title = "Design {{feature_name}}"
type = "human"
description = "Create design document"

[[steps]]
id = "implement"
title = "Implement {{feature_name}}"
needs = ["design"]

[[steps]]
id = "review"
title = "Code review"
needs = ["implement"]
type = "human"

[[steps]]
id = "merge"
title = "Merge to main"
needs = ["review"]

JSON Format

json
{
  "formula": "feature-workflow",
  "description": "Standard feature development workflow",
  "version": 1,
  "type": "workflow",
  "vars": {
    "feature_name": {
      "description": "Name of the feature",
      "required": true
    }
  },
  "steps": [
    {
      "id": "design",
      "title": "Design {{feature_name}}",
      "type": "human"
    },
    {
      "id": "implement",
      "title": "Implement {{feature_name}}",
      "needs": ["design"]
    }
  ]
}

Formula Types

TypeDescription
workflowStandard step sequence
expansionTemplate for expansion operator
aspectCross-cutting concerns

Variables

Define variables with defaults and constraints:

toml
[vars.version]
description = "Release version"
required = true
pattern = "^\\d+\\.\\d+\\.\\d+$"

[vars.environment]
description = "Target environment"
default = "staging"
enum = ["staging", "production"]

Use variables in steps:

toml
[[steps]]
title = "Deploy {{version}} to {{environment}}"

Step Types

TypeDescription
taskNormal work step (default)
humanRequires human action
gateAsync coordination point

Dependencies

Sequential

toml
[[steps]]
id = "step1"
title = "First step"

[[steps]]
id = "step2"
title = "Second step"
needs = ["step1"]

Parallel then Join

toml
[[steps]]
id = "test-unit"
title = "Unit tests"

[[steps]]
id = "test-integration"
title = "Integration tests"

[[steps]]
id = "deploy"
title = "Deploy"
needs = ["test-unit", "test-integration"]  # Waits for both

Gates

Add gates for async coordination:

toml
[[steps]]
id = "approval"
title = "Manager approval"
type = "human"

[steps.gate]
type = "human"
approvers = ["manager"]

[[steps]]
id = "deploy"
title = "Deploy to production"
needs = ["approval"]

Aspects (Cross-cutting)

Apply transformations to matching steps:

toml
formula = "security-scan"
type = "aspect"

[[advice]]
target = "*.deploy"  # Match all deploy steps

[advice.before]
id = "security-scan-{step.id}"
title = "Security scan before {step.title}"

Formula Locations

Formulas are searched in order:

  1. .beads/formulas/ (project-level)
  2. ~/.beads/formulas/ (user-level)
  3. Built-in formulas

Using Formulas

bash
# List available formulas
bd mol list

# Pour formula into molecule
bd pour <formula-name> --var key=value

# Preview what would be created
bd pour <formula-name> --dry-run

Creating Custom Formulas

  1. Create file: .beads/formulas/my-workflow.formula.toml
  2. Define structure (see examples above)
  3. Use with: bd pour my-workflow

Example: Release Formula

toml
formula = "release"
description = "Standard release workflow"
version = 1

[vars.version]
required = true
pattern = "^\\d+\\.\\d+\\.\\d+$"

[[steps]]
id = "bump-version"
title = "Bump version to {{version}}"

[[steps]]
id = "changelog"
title = "Update CHANGELOG"
needs = ["bump-version"]

[[steps]]
id = "test"
title = "Run full test suite"
needs = ["changelog"]

[[steps]]
id = "build"
title = "Build release artifacts"
needs = ["test"]

[[steps]]
id = "tag"
title = "Create git tag v{{version}}"
needs = ["build"]

[[steps]]
id = "publish"
title = "Publish release"
needs = ["tag"]
type = "human"