File	Description
`01-hello-world.prose`	Simplest possible program - a single session
`02-research-and-summarize.prose`	Research a topic, then summarize findings
`03-code-review.prose`	Multi-perspective code review pipeline
`04-write-and-refine.prose`	Draft content and iteratively improve it
`05-debug-issue.prose`	Step-by-step debugging workflow
`06-explain-codebase.prose`	Progressive exploration of a codebase
`07-refactor.prose`	Systematic refactoring workflow
`08-blog-post.prose`	End-to-end content creation

Agents & Skills (09-12)

File	Description
`09-research-with-agents.prose`	Custom agents with model selection
`10-code-review-agents.prose`	Specialized reviewer agents
`11-skills-and-imports.prose`	External skill imports
`12-secure-agent-permissions.prose`	Agent permissions and access control

Variables & Composition (13-15)

File	Description
`13-variables-and-context.prose`	let/const bindings, context passing
`14-composition-blocks.prose`	Named blocks, do blocks
`15-inline-sequences.prose`	Arrow operator chains

Parallel Execution (16-19)

File	Description
`16-parallel-reviews.prose`	Basic parallel execution
`17-parallel-research.prose`	Named parallel results
`18-mixed-parallel-sequential.prose`	Combined parallel and sequential patterns
`19-advanced-parallel.prose`	Join strategies, failure policies

Loops (20)

File	Description
`20-fixed-loops.prose`	repeat, for-each, parallel for patterns

Pipelines (21)

File	Description
`21-pipeline-operations.prose`	map, filter, reduce, pmap transformations

Error Handling (22-23)

File	Description
`22-error-handling.prose`	try/catch/finally patterns
`23-retry-with-backoff.prose`	Resilient API calls with retry/backoff

Advanced Features (24-27)

File	Description
`24-choice-blocks.prose`	AI-selected branching
`25-conditionals.prose`	if/elif/else patterns
`26-parameterized-blocks.prose`	Reusable blocks with arguments
`27-string-interpolation.prose`	Dynamic prompts with {var} syntax

Orchestration Systems (28-31)

File	Description
`28-gas-town.prose`	Multi-agent orchestration ("Kubernetes for agents") with 7 worker roles, patrols, convoys, and GUPP propulsion
`29-captains-chair.prose`	Full captain's chair pattern: coordinating agent dispatches subagents for all work, with parallel research, critic review cycles, and checkpoint validation
`30-captains-chair-simple.prose`	Minimal captain's chair: core pattern without complexity
`31-captains-chair-with-memory.prose`	Captain's chair with retrospective analysis and session-to-session learning

The Captain's Chair Pattern

The captain's chair is an orchestration paradigm where a coordinating agent (the "captain") dispatches specialized subagents for all execution. The captain never writes code directly—only plans, coordinates, and validates.

Key principles:

Context isolation: Subagents receive targeted context, not everything
Parallel execution: Multiple subagents work concurrently where possible
Continuous criticism: Critic agents review plans and outputs mid-stream
80/20 planning: 80% effort on planning, 20% on execution oversight
Checkpoint validation: User approval at key decision points

# The core pattern
agent captain:
  model: opus
  prompt: "Coordinate but never execute directly"

agent executor:
  model: sonnet
  prompt: "Execute assigned tasks precisely"

agent critic:
  model: sonnet
  prompt: "Review work and find issues"

# Captain plans
let plan = session: captain
  prompt: "Break down this task"

# Parallel execution with criticism
parallel:
  work = session: executor
    context: plan
  review = session: critic
    context: plan

# Captain validates
output result = session: captain
  prompt: "Validate and integrate"
  context: { work, review }

See examples 29-31 for full implementations.

Running Examples

Ask Claude to run any example:

Run the code review example from the OpenProse examples

Or reference the file directly:

Execute examples/03-code-review.prose

Feature Reference

Core Syntax

# Comments
session "prompt"                    # Simple session
let x = session "..."               # Variable binding
const y = session "..."             # Immutable binding

Agents

agent name:
  model: sonnet                     # haiku, sonnet, opus
  prompt: "System prompt"
  skills: ["skill1", "skill2"]
  permissions:
    read: ["*.md"]
    bash: deny

Parallel

parallel:                           # Basic parallel
  a = session "A"
  b = session "B"

parallel ("first"):                 # Race - first wins
parallel ("any", count: 2):         # Wait for N successes
parallel (on-fail: "continue"):     # Don't fail on errors

Loops

repeat 3:                           # Fixed iterations
  session "..."

for item in items:                  # For-each
  session "..."

parallel for item in items:         # Parallel for-each
  session "..."

loop until **condition** (max: 10): # Unbounded with AI condition
  session "..."

Pipelines

items | map:                        # Transform each
  session "..."
items | filter:                     # Keep matching
  session "..."
items | reduce(acc, x):             # Accumulate
  session "..."
items | pmap:                       # Parallel transform
  session "..."

Error Handling

try:
  session "..."
catch as err:
  session "..."
finally:
  session "..."

session "..."
  retry: 3
  backoff: "exponential"            # none, linear, exponential

throw "message"                     # Raise error

Conditionals

if **condition**:
  session "..."
elif **other condition**:
  session "..."
else:
  session "..."

Choice

choice **criteria**:
  option "Label A":
    session "..."
  option "Label B":
    session "..."

Blocks

block name(param):                  # Define with parameters
  session "... {param} ..."

do name("value")                    # Invoke with arguments

String Interpolation

let x = session "Get value"
session "Use {x} in prompt"         # Single-line

session """                         # Multi-line
Multi-line prompt with {x}
"""

Learn More

See docs.md in the skill directory for the complete language specification.