Workflow Templates

Overview

Shannon’s template system enables deterministic, zero-token workflows for common patterns. Templates define structured workflows in YAML that execute without AI decomposition, providing significant cost savings for repeatable tasks.

Zero Token Cost

Templates bypass LLM calls for workflow routing

Deterministic Execution

Predictable, repeatable workflow behavior

Budget Control

Per-node token limits with automatic degradation

DAG Support

Parallel execution with dependency management

When to Use Templates

Use templates when:

Workflows are repeatable with known structure
You want to eliminate decomposition token costs
Predictable execution order is required
Budget control per workflow stage is needed

Use AI decomposition when:

Task structure is unknown or variable
Complex reasoning about workflow design is needed
One-off or highly dynamic tasks

Template Structure

Templates are YAML files with this structure:

name: "workflow_name"
version: "1.0.0"
description: "What this workflow does"

defaults:
  model_tier: "medium"        # small | medium | large
  budget_agent_max: 6000      # Total token budget
  require_approval: false     # Human approval gate

nodes:
  - id: "step_1"
    type: "simple"            # Node type
    strategy: "react"         # Execution strategy
    tools_allowlist:          # Permitted tools
      - "web_search"
    budget_max: 1500          # Per-node token limit
    depends_on: []            # Dependencies

  - id: "step_2"
    type: "cognitive"
    strategy: "chain_of_thought"
    budget_max: 2000
    depends_on: ["step_1"]

edges:
  - from: "step_1"
    to: "step_2"

Core Fields

Field	Type	Required	Description
`name`	string	Yes	Unique workflow identifier
`version`	string	Yes	Semantic version (e.g., “1.0.0”)
`description`	string	No	Human-readable description
`defaults`	object	No	Global settings for all nodes
`nodes`	array	Yes	Workflow execution units
`edges`	array	No	Explicit dependency connections

Default Settings

defaults:
  model_tier: "medium"        # Model size for all nodes
  budget_agent_max: 6000      # Total workflow token budget
  require_approval: false     # Require human approval before execution

Node Types

Shannon supports four node types for different execution patterns:

Simple Nodes

Single-task execution with direct tool invocation.

- id: "fetch_data"
  type: "simple"
  strategy: "react"
  tools_allowlist:
    - "web_search"
  budget_max: 1000
  depends_on: []

Use for: Data fetching, simple transformations, tool-based operations.

Cognitive Nodes

Complex reasoning with multi-step analysis.

- id: "analyze"
  type: "cognitive"
  strategy: "chain_of_thought"
  budget_max: 2500
  depends_on: ["fetch_data"]
  degrade_to: "react"         # Fallback if budget exceeded
  retries: 1

Use for: Analysis, reasoning, synthesis tasks.

DAG Nodes

Parallel execution with internal task dependencies.

- id: "parallel_analysis"
  type: "dag"
  budget_max: 5000
  depends_on: ["understand"]
  metadata:
    tasks:
      - id: "collect"
        tools_allowlist: ["web_search"]
        depends_on: []
      - id: "quantitative"
        tools_allowlist: ["calculator"]
        depends_on: ["collect"]
      - id: "qualitative"
        tools_allowlist: []
        depends_on: ["collect"]
      - id: "cross_validate"
        depends_on: ["quantitative", "qualitative"]

Use for: Parallel processing, fan-out/fan-in patterns.

Supervisor Nodes

Hierarchical task decomposition and coordination.

- id: "orchestrate"
  type: "supervisor"
  strategy: "reflection"
  budget_max: 3000
  depends_on: ["parallel_analysis"]

Use for: Result aggregation, quality control, synthesis.

Execution Strategies

Strategies define how nodes process tasks:

Strategy	Token Range	Description
`react`	~500-1500	Tool-based reasoning with action cycles
`chain_of_thought`	~1500-3000	Sequential step-by-step reasoning
`tree_of_thoughts`	~3000-8000	Explores multiple reasoning branches
`reflection`	~1000-2000	Self-evaluation and refinement
`debate`	~2000-4000	Multi-perspective analysis

Automatic Degradation

When budget constraints are reached, strategies degrade automatically:

tree_of_thoughts → chain_of_thought → react

Configure explicit degradation:

- id: "explore"
  type: "cognitive"
  strategy: "tree_of_thoughts"
  budget_max: 2500
  degrade_to: "chain_of_thought"  # Fallback strategy
  retries: 1                       # Retry count on degradation

Creating Templates

Create Template File

Create a YAML file in config/workflows/examples/ or your custom directory:

# config/workflows/examples/my_workflow.yaml
name: "my_workflow"
version: "1.0.0"
description: "Custom analysis workflow"

defaults:
  model_tier: "medium"
  budget_agent_max: 5000
  require_approval: false

nodes:
  - id: "intake"
    type: "simple"
    strategy: "react"
    tools_allowlist:
      - "web_search"
    budget_max: 1500
    depends_on: []

  - id: "analyze"
    type: "cognitive"
    strategy: "chain_of_thought"
    budget_max: 2000
    depends_on: ["intake"]

  - id: "synthesize"
    type: "cognitive"
    strategy: "reflection"
    budget_max: 1500
    depends_on: ["analyze"]

edges:
  - from: "intake"
    to: "analyze"
  - from: "analyze"
    to: "synthesize"

Templates are loaded at startup via InitTemplateRegistry:

// In orchestrator initialization
registry := templates.InitTemplateRegistry(
    "./config/workflows/builtin",
    "./config/workflows/examples",  // Your templates
)

// Validate all templates
if err := registry.Finalize(); err != nil {
    log.Fatal(err)
}

Restart Services

docker compose -f deploy/compose/docker-compose.yml up -d --force-recreate orchestrator

List Available Templates

Via gRPC:

grpcurl -plaintext -d '{}' localhost:50052 \
  shannon.orchestrator.OrchestratorService/ListTemplates

Using Templates

Via HTTP Gateway

curl -X POST http://localhost:8080/api/v1/tasks \
  -H "Content-Type: application/json" \
  -d '{
    "query": "Analyze the current AI market trends",
    "context": {
      "template": "my_workflow",
      "template_version": "1.0.0"
    }
  }'

Via gRPC

grpcurl -plaintext -d '{
  "query": "Analyze the current AI market trends",
  "context": {
    "template": "my_workflow",
    "template_version": "1.0.0",
    "disable_ai": true
  }
}' localhost:50052 shannon.orchestrator.OrchestratorService/SubmitTask

Set disable_ai: true to enforce template-only execution without AI fallback.

Via Python SDK

from shannon import ShannonClient

client = ShannonClient(base_url="http://localhost:8080")
handle = client.submit_task(
    "Analyze the current AI market trends",
    context={
        "template": "my_workflow",
        "template_version": "1.0.0",
    },
)
result = client.wait(handle.task_id)
print(result.result)

Template Examples

Simple Analysis Workflow

Two-stage pipeline for quick summarization:

name: "simple_analysis"
version: "1.0.0"
description: "Quick summarization workflow for short briefs"

defaults:
  model_tier: "medium"
  budget_agent_max: 3000
  require_approval: false

nodes:
  - id: "intake"
    type: "simple"
    strategy: "react"
    budget_max: 1000
    depends_on: []

  - id: "summarize"
    type: "cognitive"
    strategy: "chain_of_thought"
    budget_max: 1200
    depends_on: ["intake"]

edges:
  - from: "intake"
    to: "summarize"

Research Summary Workflow

Four-stage research pipeline with progressive reasoning:

name: "research_summary"
version: "1.0.0"
description: "Multi-stage research workflow"

defaults:
  model_tier: "medium"
  budget_agent_max: 6000
  require_approval: false

nodes:
  - id: "discover"
    type: "simple"
    strategy: "react"
    tools_allowlist:
      - "web_search"
    budget_max: 1500
    depends_on: []

  - id: "reason"
    type: "cognitive"
    strategy: "chain_of_thought"
    budget_max: 1500
    depends_on: ["discover"]

  - id: "explore"
    type: "cognitive"
    strategy: "tree_of_thoughts"
    budget_max: 2500
    degrade_to: "chain_of_thought"
    retries: 1
    depends_on: ["reason"]

  - id: "finalize"
    type: "cognitive"
    strategy: "reflection"
    budget_max: 1000
    depends_on: ["explore"]

edges:
  - from: "discover"
    to: "reason"
  - from: "reason"
    to: "explore"
  - from: "explore"
    to: "finalize"

Parallel DAG Workflow

Complex workflow with parallel execution branches:

name: "parallel_analysis"
version: "1.0.0"
description: "Parallel analysis with convergence"

defaults:
  model_tier: "medium"
  budget_agent_max: 8000
  require_approval: false

nodes:
  - id: "understand"
    type: "simple"
    strategy: "react"
    budget_max: 1000
    depends_on: []

  - id: "parallel_analysis"
    type: "dag"
    budget_max: 5000
    depends_on: ["understand"]
    metadata:
      tasks:
        - id: "collect"
          tools_allowlist: ["web_search"]
          depends_on: []
        - id: "quantitative"
          tools_allowlist: ["calculator"]
          depends_on: ["collect"]
        - id: "qualitative"
          tools_allowlist: []
          depends_on: ["collect"]
        - id: "cross_validate"
          depends_on: ["quantitative", "qualitative"]

  - id: "report"
    type: "cognitive"
    strategy: "reflection"
    budget_max: 2000
    degrade_to: "chain_of_thought"
    depends_on: ["parallel_analysis"]

edges:
  - from: "understand"
    to: "parallel_analysis"
  - from: "parallel_analysis"
    to: "report"

Template Inheritance

Templates can inherit from parent templates using extends:

# base_research.yaml
name: "base_research"
version: "1.0.0"

defaults:
  model_tier: "medium"
  budget_agent_max: 5000
  require_approval: false

# advanced_research.yaml
name: "advanced_research"
version: "1.0.0"
extends: ["base_research"]    # Inherits all defaults

defaults:
  budget_agent_max: 10000     # Override specific values

nodes:
  # ... additional nodes

Multiple parents are applied in order, with the derived template’s values taking precedence.

Validation

Templates are validated at load time for:

YAML syntax correctness
Required field presence
DAG acyclicity (no circular dependencies)
Budget hierarchy (node budgets ≤ agent budget)
Tool registry existence
Variable reference resolution

registry := templates.InitTemplateRegistry("./templates")

// Validates all templates
if err := registry.Finalize(); err != nil {
    log.Fatalf("Template validation failed: %v", err)
}

Best Practices

Keep Nodes Small and Focused

Each node should do one thing well:

# Good: Focused nodes
- id: "search"
  type: "simple"
  strategy: "react"
  tools_allowlist: ["web_search"]

- id: "analyze"
  type: "cognitive"
  strategy: "chain_of_thought"

Explicitly Allowlist Tools

Restrict tools per node for security and predictability:

# Good: Explicit allowlist
tools_allowlist:
  - "web_search"
  - "calculator"

# Bad: Allowing all tools
# tools_allowlist: ["*"]

Use Budget Degradation

Configure fallback strategies for cost control:

- id: "explore"
  strategy: "tree_of_thoughts"
  budget_max: 2500
  degrade_to: "chain_of_thought"
  retries: 1

Use Inheritance for Common Patterns

Extract shared defaults into base templates:

extends: ["base_research"]
defaults:
  budget_agent_max: 8000  # Only override what changes

Version Your Templates

Use semantic versioning and specify version in requests:

name: "my_workflow"
version: "1.0.0"  # Increment on breaking changes

{
  "context": {
    "template": "my_workflow",
    "template_version": "1.0.0"
  }
}

Troubleshooting

Template Not Found

Symptom: template 'my_workflow' not foundSolutions:

Check template file exists in registered directory
Verify YAML syntax: yamllint config/workflows/examples/my_workflow.yaml
Restart orchestrator to reload templates
Check orchestrator logs for load errors

Validation Errors

Symptom: Template validation failed: circular dependencySolutions:

Review depends_on fields for cycles
Ensure DAG nodes have acyclic task dependencies
Check edges don’t create loops

Budget Exceeded

Symptom: Node execution stops early or degrades unexpectedlySolutions:

Increase budget_max for affected nodes
Configure degrade_to for graceful fallback
Review total budget vs. sum of node budgets

Tools Not Available

Symptom: tool 'my_tool' not registeredSolutions:

Verify tool is registered in tool registry
Check tool name spelling in tools_allowlist
Ensure LLM service has tool loaded

Synthesis Templates

Synthesis templates control how Shannon formats final output after all agents complete their work. These Go templates live in config/templates/synthesis/ and are rendered by the Orchestrator before returning results.

Available Templates

Template	Purpose
`normal_default.tmpl`	Default for non-research tasks
`research_comprehensive.tmpl`	Detailed research reports
`research_concise.tmpl`	Brief research summaries
`research_with_facts.tmpl`	Research with fact-based citations
`domain_analysis_digest.tmpl`	Domain analysis format
`swarm_default.tmpl`	Swarm multi-agent output
`test_bullet_summary.tmpl`	Bullet-point test format

Base Contract

All synthesis templates inherit behavioral rules from _base.tmpl:

Citation Handling

When CitationAgent is enabled: no inline [n] citations in synthesis — Citation Agent adds them separately
When CitationAgent is disabled: use inline [n] matching the AvailableCitations list

Temporal References

The CurrentDate field is injected into every template, enabling “as of” statements for time-sensitive content.

Structured Artifacts

Templates must preserve structured artifacts (tables, code blocks, JSON) — never flatten them to prose.

Source Sections

Templates should not include a “Sources” section. The system appends source citations automatically.

Template Data

Every synthesis template receives a SynthesisTemplateData struct with the following fields:

type SynthesisTemplateData struct {
    Query                string   // Original user query
    QueryLanguage        string   // Detected language (e.g., "en", "ja")
    ResearchAreas        []string // Topics explored by agents
    AvailableCitations   string   // Formatted citation list
    CitationCount        int      // Total citations available
    MinCitations         int      // Minimum citations to include
    LanguageInstruction  string   // Output language directive
    AgentResults         string   // Combined agent output
    TargetWords          int      // Target word count
    IsResearch           bool     // Whether task is research-type
    SynthesisStyle       string   // Selected synthesis style
    CitationAgentEnabled bool     // Whether Citation Agent is active
    CurrentDate          string   // Current date for temporal context
    NewsCount            int      // Number of news items found
}

Selecting a Synthesis Template

The Orchestrator selects synthesis templates based on the task type and configuration:

Via Task Context
Via Workflow Template

curl -X POST http://localhost:8080/api/v1/tasks \
  -H "Content-Type: application/json" \
  -d '{
    "query": "Research quantum computing trends",
    "context": {
      "synthesis_style": "research_comprehensive"
    }
  }'

name: "my_research"
version: "1.0.0"
defaults:
  model_tier: "medium"
  synthesis_style: "research_with_facts"

If no synthesis_style is specified, Shannon automatically selects research_comprehensive for research tasks and normal_default for all others.

Example Workflows

Shannon ships with 8 example workflow templates in config/workflows/examples/. These serve as ready-to-use starting points and reference implementations.

Workflow Catalog

Template	Description	Nodes	Pattern
`simple_analysis.yaml`	Quick summarization	2	Sequential (intake + summarize)
`research_summary.yaml`	Multi-stage research	4	Sequential with degradation
`research_summary_enterprise.yaml`	Enterprise research	4+	Sequential with large models
`market_analysis.yaml`	Market research	3+	Sequential with tools
`market_analysis_playbook.yaml`	Market playbook variant	3+	Playbook-driven
`complex_dag.yaml`	Multi-parallel DAG	5+	DAG with fan-out/fan-in
`parallel_dag_example.yaml`	Parallel execution demo	4+	DAG with parallel branches
`parallel_items_example.yaml`	Batch item processing	3+	Parallel items

YAML Structure Reference

All example workflows follow this structure:

name: workflow_id
description: "Description"

defaults:
  model_tier: small|medium|large    # Model size for all nodes
  budget_agent_max: 3000            # Total token budget
  require_approval: false           # Human-in-the-loop gate

nodes:
  - id: node_id
    type: simple|cognitive|dag      # Execution type
    strategy: react|chain_of_thought|tree_of_thoughts
    depends_on: [other_node_ids]    # DAG dependencies
    budget_max: 1000                # Per-node token limit

edges:
  - from: node1
    to: node2

Pattern Degradation

Example workflows demonstrate Shannon’s automatic degradation behavior when resources are constrained:

DAG        → sequential        (if insufficient agents available)
tree_of_thoughts → chain_of_thought  (if budget constrained)
multi-node → single-node       (fallback for minimal environments)

Degradation is automatic and logged. Check Orchestrator logs for strategy_degraded events to monitor when fallbacks activate.

Learning Router

When enabled, the Learning Router automatically selects workflow templates based on query similarity to past successful executions. This eliminates the need for callers to specify a template explicitly.

# Enable learning router via environment
ORCHESTRATOR_LEARNING_ROUTER_ENABLED=true

# The router will match incoming queries to historical patterns
# and select the best-performing template automatically

The Learning Router improves over time. For new deployments, explicitly specify templates until enough execution history accumulates (typically 50+ successful tasks).

Next Steps

Custom Tools

Add tools for your templates

Extending Shannon

Other extension methods

Configuration

Environment and YAML config

Architecture

Understanding Shannon’s design

​Overview

Zero Token Cost

Deterministic Execution

Budget Control

DAG Support

​When to Use Templates

​Template Structure

​Core Fields

​Default Settings

​Node Types

​Simple Nodes

​Cognitive Nodes

​DAG Nodes

​Supervisor Nodes

​Execution Strategies

​Automatic Degradation

​Creating Templates

​Using Templates

​Via HTTP Gateway

​Via gRPC

​Via Python SDK

​Template Examples

​Simple Analysis Workflow

​Research Summary Workflow

​Parallel DAG Workflow

​Template Inheritance

​Validation

​Best Practices

​Troubleshooting

​Synthesis Templates

​Available Templates

​Base Contract

​Template Data

​Selecting a Synthesis Template

​Example Workflows

​Workflow Catalog

​YAML Structure Reference

​Pattern Degradation

​Learning Router

​Next Steps

Custom Tools

Extending Shannon

Configuration

Architecture

Overview

When to Use Templates

Template Structure

Core Fields

Default Settings

Node Types

Simple Nodes

Cognitive Nodes

DAG Nodes

Supervisor Nodes

Execution Strategies

Automatic Degradation

Creating Templates

Using Templates

Via HTTP Gateway

Via gRPC

Via Python SDK

Template Examples

Simple Analysis Workflow

Research Summary Workflow

Parallel DAG Workflow

Template Inheritance

Validation

Best Practices

Troubleshooting

Synthesis Templates

Available Templates

Base Contract

Template Data

Selecting a Synthesis Template

Example Workflows

Workflow Catalog

YAML Structure Reference

Pattern Degradation

Learning Router

Next Steps