WP A2E

Workflow engine for WordPress 7.0 — orchestrate abilities into multi-step workflows where each step's output feeds the next.

The GPL alternative to n8n. No external dependencies, no restrictive licenses.

No core modifications. Pure plugin, GPL-2.0.

The Complete Stack

Connectors (vault)  →  Abilities (nodes)  →  A2E (workflows)
      ↕                      ↕                      ↕
  AES-256-CBC          6 types + ACL          9 ops + log
  AI + generic         REST + MCP            register as ability

Layer	Plugin	What it does
Credentials	WP Connector Factory	Encrypted vault (AES-256-CBC), AI + generic connectors
Nodes	WP Ability Factory	6 ability types: AI, API, WP, Function, Hook, Cron. MCP exposure control. App-password ACL.
Orchestration	WP A2E	Sequential workflow execution with data store, execution log, register-as-ability

Requirements

• WordPress 7.0+
• PHP 8.1+
• WP Ability Factory (recommended — provides the abilities A2E orchestrates)
• WP Connector Factory (recommended — provides credential vault)

How it works

A workflow is an ordered list of steps. Each step executes an operation and stores its result in a shared data store. Subsequent steps reference previous results using /step_id path syntax.

$workflow = [
    // Step 1: Call an ability to get posts
    ['id' => 'posts',  'type' => 'ExecuteAbility', 'ability' => 'my/list-posts', 'input' => ['posts_per_page' => 10]],

    // Step 2: Filter results — /posts references step 1's output
    ['id' => 'recent', 'type' => 'FilterData', 'data' => '/posts', 'field' => 'status', 'operator' => 'eq', 'value' => 'publish'],

    // Step 3: Extract just the titles
    ['id' => 'titles', 'type' => 'TransformData', 'data' => '/recent', 'operation' => 'map', 'field' => 'title'],

    // Step 4: Summarize with AI — /titles feeds into the ability input
    ['id' => 'summary', 'type' => 'ExecuteAbility', 'ability' => 'my/summarize', 'input' => ['content' => '/titles']],
];

After execution, the data store contains every step's result:

/posts   → [{ID: 1, title: "Hello", ...}, ...]
/recent  → [{ID: 1, title: "Hello", ...}]
/titles  → ["Hello"]
/summary → "The site has one post titled Hello..."

Operations (9)

ExecuteAbility

Call any registered WordPress ability. This is the bridge between A2E workflows and the Ability Factory ecosystem.

{"id": "fetch", "type": "ExecuteAbility", "ability": "my/list-posts", "input": {"posts_per_page": 5}}

ApiCall

Direct HTTP request without needing a pre-defined ability.

{"id": "api", "type": "ApiCall", "url": "https://api.example.com/data", "method": "GET", "headers": {"Authorization": "Bearer token"}}

FilterData

Filter an array by field value. Operators: eq, neq, gt, gte, lt, lte, contains, startsWith, endsWith, in, exists, empty.

{"id": "active", "type": "FilterData", "data": "/users", "field": "status", "operator": "eq", "value": "active"}

TransformData

Transform arrays. Operations: select, sort, group, aggregate, map, flatten, unique, reverse, slice, count.

{"id": "names", "type": "TransformData", "data": "/users", "operation": "map", "field": "name"}

Conditional

Branch execution based on a condition.

{"id": "check", "type": "Conditional", "left": "/count", "operator": "gt", "right": 0,
  "then": [{"id": "notify", "type": "ExecuteAbility", "ability": "my/send-email", "input": {"body": "/titles"}}],
  "else": [{"id": "log", "type": "StoreData", "key": "message", "value": "No posts found"}]
}

Loop

Iterate over an array, executing sub-steps for each item. Max 1000 iterations.

{"id": "process", "type": "Loop", "data": "/posts", "as": "_item", "index_as": "_index",
  "steps": [{"id": "tag", "type": "ExecuteAbility", "ability": "my/tag-post", "input": {"post_id": "/_item.ID"}}]
}

StoreData

Write a value to the data store.

{"id": "save", "type": "StoreData", "key": "final_result", "value": "/processed"}

Wait

Pause execution (max 30 seconds).

{"id": "pause", "type": "Wait", "seconds": 2}

MergeData

Combine data from multiple sources. Modes: concat, union, intersect, deepMerge, zip.

{"id": "combined", "type": "MergeData", "sources": ["/list_a", "/list_b"], "mode": "concat"}

Path References

Values starting with / are resolved from the data store at execution time:

Syntax	Resolves to
/step_id	Full result of that step
/step_id.field	Nested field access
/step_id.0.title	Array index + field
/step_id.length	Count of array result
plain value	Passed as-is (no resolution)

Execution Log

Every workflow execution is recorded in a custom database table (wp_a2e_executions) for auditing, debugging, and analytics.

Log Fields

Field	Type	Description
id	bigint	Auto-increment primary key
workflow_id	varchar	Workflow slug/ID
name	varchar	Workflow display name
trigger_source	varchar	How it was triggered: rest, ability, cli, manual
user_id	bigint	WordPress user who initiated the execution
status	varchar	completed or failed
steps_total	int	Total steps in the workflow
steps_run	int	Steps actually executed (may differ on error)
duration_ms	int	Wall-clock execution time in milliseconds
data_store	longtext	Full data-store snapshot at completion (JSON)
errors	longtext	Error details if any (JSON)
created_at	datetime	When execution started
updated_at	datetime	When execution finished

REST Endpoints for Execution Log

GET /wp-a2e/v1/executions           List executions + aggregate stats
GET /wp-a2e/v1/executions/{id}      Single execution detail

The list endpoint returns both the execution rows and an aggregate stats object:

{
  "executions": [ ... ],
  "stats": {
    "total": 142,
    "completed": 138,
    "failed": 4,
    "avg_ms": 1230,
    "today": 17
  }
}

Purge

Old execution records can be purged programmatically:

WP_A2E_Execution_Log::purge_older_than( 30 ); // days

Register Workflow as Ability

Any saved workflow can be published as a WordPress ability, making it callable by other plugins, REST clients, and MCP-connected agents.

In the workflow editor:

1. Check Register as Ability
2. Set an Ability Name (e.g. a2e/my-pipeline)
3. Choose a Return Step — the step whose output becomes the ability's return value

All workflow-registered abilities have meta.mcp.public = true by default, so they are automatically discoverable by MCP agents.

When executed as an ability, the workflow receives the ability input as its initial data store and returns the selected step's result.

REST API

GET    /wp-a2e/v1/health                         Service status
GET    /wp-a2e/v1/workflows                      List all workflows
POST   /wp-a2e/v1/workflows                      Create/update workflow
GET    /wp-a2e/v1/workflows/{id}                  Get workflow definition
DELETE /wp-a2e/v1/workflows/{id}                  Delete workflow
POST   /wp-a2e/v1/workflows/{id}/execute          Execute saved workflow
POST   /wp-a2e/v1/execute                         Execute inline workflow (JSON body)
GET    /wp-a2e/v1/executions                      List executions + stats
GET    /wp-a2e/v1/executions/{id}                 Single execution detail

Execute a saved workflow

curl -X POST http://localhost/wp7/index.php?rest_route=/wp-a2e/v1/workflows/my-flow/execute \
  -H "Content-Type: application/json" \
  -d '{"input": {"key": "value"}}'

Execute inline

curl -X POST http://localhost/wp7/index.php?rest_route=/wp-a2e/v1/execute \
  -H "Content-Type: application/json" \
  -d '{"steps": [{"id": "s1", "type": "StoreData", "key": "hello", "value": "world"}]}'

MCP Integration

A2E registers two built-in abilities in the WordPress Abilities API:

Ability	Description
a2e/execute-workflow	Execute a saved workflow by ID
a2e/list-workflows	List all available workflows

Additionally, any workflow with Register as Ability enabled becomes its own MCP-discoverable ability (see above).

Any MCP-connected AI agent can discover and execute workflows:

Agent → MCP Adapter → a2e/execute-workflow → A2E Engine → Abilities → Results

Architecture

wp-a2e/
├── wp-a2e.php                      Bootstrap, singleton
├── includes/
│   ├── class-data-store.php        In-memory key-value store per execution
│   ├── class-path-resolver.php     /step_id.field resolution engine
│   ├── class-executor.php          Sequential step executor with error handling
│   ├── class-workflow-storage.php  CRUD for workflow definitions (wp_options)
│   ├── class-execution-log.php     Custom DB table for execution history + purge
│   ├── class-rest-api.php          REST endpoints for CRUD, execution, and log
│   ├── class-abilities.php         Registers a2e/* abilities + workflow-as-ability
│   ├── class-admin-page.php        Visual workflow builder
│   └── operations/
│       ├── class-execute-ability.php
│       ├── class-api-call.php
│       ├── class-filter-data.php
│       ├── class-transform-data.php
│       ├── class-conditional.php
│       ├── class-loop.php
│       ├── class-store-data.php
│       ├── class-wait.php
│       └── class-merge-data.php
├── js/admin.js
└── css/admin.css

Error Handling

• Steps that return WP_Error stop the workflow by default
• Add "continue_on_error": true to a step to continue on failure
• Error details stored in the data store under the step's ID
• Execution result includes errors array with step ID, type, code, and message
• All errors are persisted in the execution log for post-mortem debugging

License

GPL-2.0-or-later