> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sixtyfour.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Workflow Blocks
> Reference for all workflow block types supported by the Workflows API.
## Use case
Discover which block types you can use when building workflows. Use `GET /workflows/blocks` to retrieve the full list and specs schemas programmatically. This page provides a quick reference for common use cases.
See the full request/response schema and parameters in the API Reference.
## Pricing
See [Credits & Pricing Guide](/guides/credits-and-pricing) for credit costs.
## Errors
For error responses (400, 403, 404, etc.), see [Handling Errors](/api-reference/errors).
## Get available blocks
Retrieve the list of all workflow block types supported by the API, along with their specs schemas.
```http theme={null}
GET https://api.sixtyfour.ai/workflows/blocks
```
Returns an array of block descriptors. Each entry includes the block's name (used as `block_type` when building a workflow) and a `specs_schema` object describing its configurable fields.
## Available blocks
The UI name is the name of the block as it appears in the Workflow Builder.
| Block Type | UI Name | Use Case |
| ----------------------------- | ------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `append_to_notebook` | Notebook | Append or upsert workflow rows into a notebook (supports duplicate detection and column mapping) |
| `backlinks_referring_domains` | Backlinks | Get referring domains data from DataForSEO Backlinks API for a target domain or URL, with pagination |
| `breached_db_search` | Breached Database Search | Look up whether email addresses appear in known data breaches (HIBP/Snusbase) |
| `company_enrichment` | Enrich Company | Enrich company records; optionally find people, define lead struct, or use a research plan |
| `company_to_leads` | Extract Leads | Expand company rows into individual lead records (select company/lead fields) |
| `deduplicate` | Deduplicate | Remove duplicate rows from input based on specified column(s); choose first, last, or remove all |
| `deduplicate_wrt_notebook` | Deduplicate with Notebook | Deduplicate against a notebook tab (single or multi-column matching); optionally keep only rows that exist in notebook |
| `filter` | Filter | Filter rows by pandas query string or field-based conditions (include, exclude, contains, not\_contains) |
| `find_email` | Email address | Find professional or personal email addresses for leads; optionally verify emails |
| `find_phone` | Phone | Find phone numbers for leads |
| `find_subdomains` | Find Subdomains | Find subdomains for a domain using DNSDB API (with optional time filters) |
| `github_find_people` | GitHub Find People | Find people from GitHub repos: contributors, stargazers, or watchers; requires integration and repository column |
| `github_search` | GitHub Search | Search GitHub for repositories, users, or code; requires integration, search type, and query |
| `google_maps_search` | Google Maps | Search Google Maps for places by query, location, Place ID, or CID; returns phone numbers and business details; supports pagination |
| `group_by` | Group By | Group rows by column(s) and aggregate others (first, last, count, sum, list, concat, min, max); optionally nest data |
| `hubspot_import` | HubSpot Import | Import contacts or companies from HubSpot; requires integration and object type |
| `kaggle_leaderboard` | Kaggle | Get leaderboard participants from Kaggle competitions; requires competition column |
| `lead_enrichment` | Enrich People | Enrich lead records with return fields and optional research plan |
| `leads_to_company` | Leads to Company | Group leads into company rows with nested leads list; inverse of `company_to_leads` |
| `llm_openai` | Generate Text | Generate text via prompt template over input rows; use `{column_name}` for column substitution |
| `outgoing_webhook` | Outgoing Webhooks | POST workflow results to an external URL on completion. See [Outgoing Webhooks](/api-reference/webhooks/outgoing); signed with HMAC-SHA256 if the org has a signing secret — see [Signing Secrets & Verification](/api-reference/webhooks/signing-secrets). |
| `qa_agent` | N/A | Run an agent that answers questions using tools; configurable max tool calls |
| `read_notebook` | Read Notebook | Read data from a notebook tab; requires `notebook_id`, `tab_id`, and `dataframe` type (LEAD or COMPANY) |
| `remove_columns` | Remove Columns | Remove specified columns from the data |
| `research_agent` | Web Research Agent | Run research with optional struct and research plan |
| `reverse_email` | Reverse Email | Look up person or company info from an email address |
| `reverse_phone` | Reverse Phone | Look up person or company info from a phone number |
| `scrape_web` | Scrape Website | Scrape web content from URLs in a column; output as markdown or HTML; supports geo, JS rendering, proxies |
| `search` | Search | Load search results persisted to storage as CSV, or accept direct results; requires dataframe type |
| `send_slack_message` | Slack | Send Slack messages to channels or DMs; use `{column}` for substitution, `{@column}` to tag by email |
| `tiktok_get_following` | TikTok | Get TikTok following list from profile URLs or handles in a column |
| `transform_data` | LLM Output | Generate structured or unstructured text using configurable LLM models |
| `verify_email` | Verify Email | Verify email deliverability using Emailable API (default column: email) |
| `verify_phone` | Verify Phone | Verify phone numbers using Trestle phone\_intel; returns validity, line type, carrier, activity score, prepaid flag, and country signals (default column: phone; optional `country_hint`) |
| `webhook` | Incoming Webhooks | Accept external input via webhook; requires input\_schema and `dataframe_type` (workflow entry point). See [Incoming Webhooks](/api-reference/webhooks/incoming). |
| `x_search` | X | Search X/Twitter for profiles by query (e.g., "AI researchers", "crypto founders in NYC") |
| `yc_batches` | N/A | Fetch Y Combinator batch metadata |
| `yc_companies` | Y Combinator | Search or filter Y Combinator companies by batch, industry, tags, or status |