Reference
Reference
Complete reference for connectors, blocks, the CLI, CEL, and the flow file format.
This section is the complete reference for everything you can put in a flow file: every connector, source, and block type, plus the CLI, the CEL expression language, and the flow file schema.
The tables below catalogue every type by category. Connectors are configured under connectors: and referenced by name; sources bind a flow's entry point to a connector; blocks are the steps of a flow's process chain.
Triggers and sources
| Type | Description | Reference |
|---|---|---|
http | HTTP server connector; routes requests into flows and returns the flow result. | HTTP |
cron | Trigger flows on a schedule. | Cron |
events | Broadcast pub/sub topics; every subscriber flow receives each event. | Events |
queue | Competing-consumer queues; one worker flow receives each message. | Queue |
Service connectors
| Type | Description | Reference |
|---|---|---|
http-client | Outbound HTTP with base URL, timeouts, and auth (used by the rest block). | HTTP |
database | SQL databases (used by the sql block). | Database |
logger | Structured logging (used by the log block). | Logger |
slack | Slack workspace connection for messaging and events. | Slack |
notion | Notion workspace connection for pages, data sources, and webhooks. | Notion |
llm-openai | OpenAI LLM provider for the AI blocks. | LLM Providers |
llm-anthropic | Anthropic LLM provider for the AI blocks. | LLM Providers |
llm-gemini | Google Gemini LLM provider for the AI blocks. | LLM Providers |
Control-flow blocks
Composites configured with top-level YAML keys, not settings:. All on one page: Control Flow.
| Type | Description |
|---|---|
if | Conditional branching on a CEL boolean expression. |
switch | Multi-case routing; runs the first matching case or the default. |
fork | Scatter the message across parallel branches, then join and pass through. |
foreach | Sequentially iterate an array, running the body per element. |
enrich | Run a body flow on an isolated copy, then merge back only the named body/variables. |
validate | Assert CEL rules; reject and stop the flow when any fail. |
handle-errors | Run a process chain; on error, expose vars.error and run the error chain. |
cache-scope | Memoize the body flow's result in the runtime store, keyed by a CEL expression. |
Data blocks
Reshape the message payload and variables: Data.
| Type | Description |
|---|---|
set-payload | Replace the message body with the result of a CEL expression. |
set-variable | Store the result of a CEL expression in a named variable. |
delete-variable | Remove a named variable from the message. |
multi-transform | Apply an ordered list of additive CEL edits in one block. |
Storage blocks
The runtime key-value store: Storage.
| Type | Description |
|---|---|
object-read | Read an object from the runtime store into the body or a variable. |
object-write | Write an object to the runtime store under a key. |
object-delete | Delete an object from the runtime store by key. |
invalidate-cache | Evict a cache-scope entry by its key so the next run recomputes. |
Integration blocks
Cross-flow and cross-system glue: Integration.
| Type | Description |
|---|---|
flow-ref | Invoke another flow by name, synchronously or fire-and-forget. |
jwt-validate | Verify a bearer JWT against an OIDC provider; reject with 401 on failure. |
template-resource | Render a declared template resource against the current message. |
AI blocks
LLM-driven blocks and the MCP server: AI Blocks.
| Type | Description |
|---|---|
ai-agent | Let an LLM call flow branches as tools in a loop to accomplish a task. |
ai-router | Route the message to a named branch the LLM chooses after inspecting it. |
ai-mapping | Reshape the body to a target shape described by a prompt and optional schema. |
ai-retry | On failure, let the LLM revise the message and retry the chain. |
clear-agent-memory | Erase an ai-agent conversation thread's stored memory. |
mcp-router | Turn a flow into a stateless MCP server behind an HTTP source. |
Connector-provided blocks
Blocks that operate through a configured connector, documented alongside it.
| Type | Description | Reference |
|---|---|---|
log | Emit a structured log line through a logger connector. | Logger |
rest | Call an HTTP API through an http-client connector. | HTTP |
sql | Run a SQL statement through a database connector. | Database |
publish-event | Publish a message to a broadcast topic. | Events |
queue-dispatch | Dispatch a message onto a competing-consumer queue. | Queue |
Slack
Slack source and blocks: Slack.
| Type | Description |
|---|---|
slack-event | Source: receive Slack events (mentions, messages, and more). |
slack-send-message | Send a message to a channel or thread. |
slack-update-message | Update a previously sent message. |
slack-add-reaction | Add an emoji reaction to a message. |
slack-lookup-user | Look up a Slack user. |
slack-verify-request | Verify a Slack request signature. |
Notion
Notion source and blocks: Notion.
| Type | Description |
|---|---|
notion-event | Source: receive Notion webhook events. |
notion-query-datasource | Query a Notion data source. |
notion-retrieve-page | Retrieve a page's properties. |
notion-retrieve-blocks | Retrieve a page's block content. |
notion-page-to-markdown | Render a page as Markdown. |
notion-verify-request | Verify a Notion webhook signature. |
Language and tooling
| Reference | Description |
|---|---|
| CLI | The octo command: run, invoke, eval, schema, and version. |
| CEL Expressions | The expression language: language basics, macros, and Octo extensions. |
| Flow File | The complete YAML schema for integration definition files. |