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Actions & MCP

Actions (also called Tools in the backend) are the functions that your Agents can perform to interact with external systems and services. They extend your agents’ capabilities beyond just the language model.Built-in Actions:
NameDescriptionRequires ConfigProvider Choices
Internal SearchSearch through your organization’s indexed documents and knowledge baseYesBuilt-in with swappable components
Web SearchSearch the internet for real-time information and current eventsYesGoogle, Serper, Exa, Firecrawl (optional)
Code InterpreterExecute Python code, analyze data, and generate visualizationsNoBuilt-in
Image GenerationCreate images from text descriptions using AI modelsYesOpenAI
SCIM support for common IdPs is coming soon!
Custom Actions:
  • API Integrations: Connect to external REST APIs
  • Database Operations: Query and update databases
  • Workflow Automation: Trigger business processes
  • File Operations: Read, write, and manipulate files
You can define your own Custom Actions in the Admin Panel using an OpenAPI specification.
Model Context Protocol (MCP) is an open standard that enables AI assistants to securely access external data sources and tools. Onyx can be configured as an MCP client to interact with external systems, databases, and APIs in a controlled manner.Key features of MCP:
  • External Data Access: Connect to databases, APIs, and file systems
  • Authentication: Pass through OAuth to ensure secure access to your MCP server.
Sometimes, you need more control over your action than what is possible with a Custom Action. Since Onyx is open-source, you can extend the built-in actions to your liking!To find templates for built-in actions, see backend/onyx/tools/tool_implementations in the Onyx repository.
Extending the codebase is not recommended for most users. Before you start, please reach out to us on Slack or Discord for support!

Agents

Agents are AI assistants with custom instructions, Actions, and data access that extend the base LLM’s capabilities.
The terms Personas, Assistants, and Agents are used interchangeably throughout Onyx and refer to the same concept.
Built-in Agents:
  • id: 0 Search Agent - Uses the Search Tool to answer questions from your knowledge base
  • id: -1 General Agent - Basic chat with no tools (basic chat with an LLM)
  • id: -2 Paraphrase Agent - Uses Search Tool and quotes exact snippets from sources
  • id: -3 Art Agent - Generates images and visual content
You can create your own Agents in the Admin Panel or by API.Most Chat endpoints require an Agent IDTo find your Agent ID, you can:
  • Use the GET /persona API endpoint to list all agents
  • In the Admin Panel: Click into an agent and check the first number in the URL

Chat

The chat response system uses a packet-based architecture to deliver real-time responses to users. Instead of waiting for a complete response, the system breaks down the chat interaction into discrete packets that can be streamed incrementally.Every packet follows a consistent structure defined by the Packet class:
class Packet(BaseModel):
  ind: int        # Sequential index for ordering
  obj: PacketObj  # The actual content including type of packet
Streaming Flow:
  • A chat request triggers the streaming process
  • Various packet types are generated based on the required operations (reasoning, tool calls, AI response, documents, citations, etc.)
  • Packets are sent with sequential indices to maintain order
  • The frontend processes packets in real-time to update the UI
  • An OverallStop packet signals completion
MessageStart and MessageDeltaThese packets form the core of the streaming response system:
  • MessageStart: Initiates a new message with initial content and final search documents (if any)
  • MessageDelta: Delivers incremental text content as it’s generated
Session and Section ManagementControl packets manage the flow and lifecycle of the streaming process:
  • OverallStop: Signals the end of the entire streaming session
  • SectionEnd: Marks the completion of a packet type (reasoning, message, citations, etc.)
Tool responses are streamed in the same way as the main message response.Search Tools
  • SearchToolStart and SearchToolDelta handle document search operations
Image Generation
  • ImageGenerationToolStart, ImageGenerationToolDelta, and ImageGenerationToolHeartbeat manage AI image creation
Custom Tools
  • CustomToolStart and CustomToolDelta are used for MCP and custom Actions
The start packet signals the start of the tool response. The delta packets stream the results as they become available.
Any reasoning steps are streamed so the frontend can render them as the system is processing. Reasoning packets are generally the first ones sent.
  • ReasoningStart: Begins a reasoning section
  • ReasoningDelta: Streams the AI’s reasoning process
Citation packets associate citation ids with document ids.
  • CitationStart: Initiates citation results
  • CitationDelta: Delivers source citations and references

Connectors

When you see the term Connector in Onyx or elsewhere in this documentation, we’re generally referring to ConnectorCredentialPairs
Connectors in Onyx define the data you would like to index
  • name: Not actually displayed in the UI if ConnectorCredentialPairMetadata:name is set
  • source: Which system to connect to (see DocumentSource accordion below)
  • input_type: How the Connector retrieves data (see InputType accordion below)
  • connector_specific_config: Source-specific settings like folder paths or channels. You will need to see /backend/onyx/connectors for the expected Connector-specific Configurations.
  • refresh_freq: How often to check for new or updated content in seconds
  • prune_freq: How often to remove old content from Onyx in seconds
  • indexing_start: Optional datetime to specify when indexing should begin
Python
class ConnectorBase(BaseModel):
  name: str
  source: DocumentSource
  input_type: InputType
  connector_specific_config: dict[str, Any]
  refresh_freq: int | None = None
  prune_freq: int | None = None
  indexing_start: datetime | None = None
Credentials contain the authentication details needed to access data sources. These include API keys, OAuth tokens, personal access tokens (PATs), or service account credentials that allow Onyx to securely connect to your external systems.Types of Credentials:
  • API Keys: Simple token-based authentication
  • OAuth Tokens: Delegated authorization with refresh capabilities
  • Service Accounts: Machine-to-machine authentication
  • Personal Access Tokens: User-specific access credentials
Behind the scenes, Connectors and Credentials are combined into a ConnectorCredentialPair (CC-pair). A CC-pair is an active connection that can sync data from your external sources into Onyx. CC-pairs are what you see and manage on the Admin Connectors page.CC-pair functionality:
  • Active Connections: Live data synchronization between source and Onyx
  • Status Monitoring: Track sync health and performance
  • Access Control: Manage who can see data from this connection
  • Configuration Management: Update sync settings and credentials
If you’re creating Connectors through the API, you must associate them with a Credential (CC-pair) to make them active!
ConnectorCredentialPairMetadata defines the configuration and access settings for a CC-pair.Configuration options:
  • name: Optional display name for the CC-pair (overrides the Connector name)
  • access_type: Who can access data from this CC-pair (see AccessType accordion below)
  • auto_sync_options: Optional configuration for automatic synchronization settings
  • groups: List of group IDs that have access to this CC-pair
Python
class ConnectorCredentialPairMetadata(BaseModel):
  name: str | None = None
  access_type: AccessType
  auto_sync_options: dict[str, Any] | None = None
  groups: list[int] = Field(default_factory=list)

Documents

DocumentBase is a core structure used throughout Onyx for storing and managing document data. Note that the embeddings are stored in Vespa separately.
  • id: Unique identifier. Generated by Onyx if not provided
  • sections: List of content sections (see TextSection and ImageSection)
  • source: The system this document originated from (see DocumentSource)
  • semantic_identifier: Displayed in the UI as the name of the Document
  • metadata: Arbitrary string or list[string] that will be saved as tags for this Document
  • doc_updated_at: UTC timestamp when the document was last updated
  • chunk_count: Number of chunks the document is split into for processing
  • primary_owners: Metadata about people associated with the Document
  • secondary_owners: Metadata about people associated with the Document
  • title: Used for search (defaults to semantic_identifier if not specified)
  • from_ingestion_api: Whether this document came from the Ingestion API
  • additional_info: Connector-specific information that other parts of the code may need
  • external_access: Permission sync data (Enterprise Edition only)
The Ingestion API extends the DocumentBase definition to include cc_pair_id to automatically associate a document with a CC-pair.
Python
class DocumentBase(BaseModel):
  """Used for Onyx ingestion api, the ID is inferred before use if not provided"""

  id: str | None = None
  sections: list[TextSection | ImageSection]
  source: DocumentSource | None = None
  semantic_identifier: str
  metadata: dict[str, str | list[str]]

  doc_updated_at: datetime | None = None
  chunk_count: int | None = None

  primary_owners: list[BasicExpertInfo] | None = None
  secondary_owners: list[BasicExpertInfo] | None = None
  title: str | None = None
  from_ingestion_api: bool = False
  additional_info: Any = None

  external_access: ExternalAccess | None = None
DocumentSource is an enum that defines the valid sources for a document. Uploading files to the Ingestion API and creating Connectors programmatically require specifying a DocumentSource.
Python
class DocumentSource(str, Enum):
  INGESTION_API = "ingestion_api"     # Special case, document passed in via Onyx APIs without specifying a source type
  SLACK = "slack"
  WEB = "web"
  GOOGLE_DRIVE = "google_drive"
  GMAIL = "gmail"
  REQUESTTRACKER = "requesttracker"
  GITHUB = "github"
  GITBOOK = "gitbook"
  GITLAB = "gitlab"
  GURU = "guru"
  BOOKSTACK = "bookstack"
  CONFLUENCE = "confluence"
  JIRA = "jira"
  SLAB = "slab"
  PRODUCTBOARD = "productboard"
  FILE = "file"
  NOTION = "notion"
  ZULIP = "zulip"
  LINEAR = "linear"
  HUBSPOT = "hubspot"
  DOCUMENT360 = "document360"
  GONG = "gong"
  GOOGLE_SITES = "google_sites"
  ZENDESK = "zendesk"
  LOOPIO = "loopio"
  DROPBOX = "dropbox"
  SHAREPOINT = "sharepoint"
  TEAMS = "teams"
  SALESFORCE = "salesforce"
  DISCOURSE = "discourse"
  AXERO = "axero"
  CLICKUP = "clickup"
  MEDIAWIKI = "mediawiki"
  WIKIPEDIA = "wikipedia"
  ASANA = "asana"
  S3 = "s3"
  R2 = "r2"
  GOOGLE_CLOUD_STORAGE = "google_cloud_storage"
  OCI_STORAGE = "oci_storage"
  XENFORO = "xenforo"
  NOT_APPLICABLE = "not_applicable"
  DISCORD = "discord"
  FRESHDESK = "freshdesk"
  FIREFLIES = "fireflies"
  EGNYTE = "egnyte"
  AIRTABLE = "airtable"
  HIGHSPOT = "highspot"

  IMAP = "imap"

  # Special case just for integration tests
  MOCK_CONNECTOR = "mock_connector"
TextSection is a portion of a Document in Onyx.
  • text: The actual text content of the section
  • link: Optional URL that this text section relates to or was sourced from
Python
class TextSection(Section):
  text: str
  link: str | None = None
ImageSection is an image extracted from a Document in Onyx.
  • image_file_id: UUID of the image file stored in Onyx’s file store
  • text: Optional text description or caption for the image
  • link: Optional URL that this image section relates to or was sourced from
Python
class ImageSection(Section):
  image_file_id: str
  text: str | None = None
  link: str | None = None
AccessType defines who can access data from a Connector in Onyx.
  • PUBLIC: All Onyx users may access data from this Connector
  • PRIVATE: Only the user who created the Connector and specified Groups may access data from this Connector
  • SYNC: Only Connectors with permission-sync support can be set to SYNC. The Connector will sync access permissions with the source system.
Python
class AccessType(str, Enum):
  PUBLIC = "public"
  PRIVATE = "private"
  SYNC = "sync"
InputType defines how a Connector retrieves data from its source system.
  • LOAD_STATE: Single load of data from the source
  • POLL: Continuous polling for new data from the source (starts with a full load)
  • EVENT: Not implemented for most Connectors
  • SLIM_RETRIEVAL: For permission-syncing Connectors
Python
class InputType(str, Enum):
  LOAD_STATE = "load_state"
  POLL = "poll"
  EVENT = "event"
  SLIM_RETRIEVAL = "slim_retrieval"

Next Steps

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