> ## Documentation Index > Fetch the complete documentation index at: https://docs.topo.io/llms.txt > Use this file to discover all available pages before exploring further. # Concepts > A short glossary of every Topo object you will meet in the API — organizations, contacts, accounts, lists, sequences, tasks, activities, webhooks, exclusions, and events. Topo's API is organized around a small set of objects. This page defines each one and points you at the endpoint group that exposes it, so you can map a concept to a request without reading every reference page. ## Workspace Your workspace, and the boundary of every API call. An API key belongs to exactly one organization and can never read or write another one, so requests carry no organization parameter. Confirm which organization a key is bound to with `GET /v1/me`. A member of your organization. Users own contacts and accounts and are the assignees of tasks, so you need their ids to reassign work through the API. ## People and companies A person in your workspace — name, email, LinkedIn URL, job title, location, and employer. Contacts are the subject of outreach: sequences, tasks, and activities all reference one. You can also attach custom variables to a contact to feed CRM data and personalization tokens into Topo's AI. A company in your workspace, keyed by its domain. Accounts carry firmographic data and are the target of account-based workflows, where you choose the companies to pursue and let Topo find the right people inside them. Like contacts, accounts hold custom variables shared by every contact linked to them. ## Lists A **contact list** is a staging area for prospects before they enter outreach. Each row in it is a **contact entry** — a raw candidate that Topo enriches and resolves to a verified contact. Create the list first, then add entries to it in batches. The company equivalent: an **account list** holds target companies, and each **account entry** is one company you added by name and domain. Same two-step shape — create the list, then add its entries. ## Outreach The outreach playbook: the ordered steps to run, which channel each one uses, the sending schedule, and how many new leads to enroll per day. Templates are read-only over the API — build and edit them in the Topo app. One contact's live run of a template, created when that contact is enrolled. It tracks their position and status, and it is the object you pause, resume, or stop when a deal changes. A manual action a sequence hands to a person — place a call, write a bespoke email, review a new lead. Tasks are assigned to a user and block the sequence step until they are completed or skipped. A blocklist rule that suppresses outreach to one person by email or LinkedIn URL across every sequence. Carries a reason code and can be permanent or time-bound. A blocklist rule that suppresses outreach to an entire company domain across every sequence. Carries a reason code and can be permanent or time-bound. ## Engagement An immutable record of something that happened during outreach — a message sent, opened, clicked, or replied to, a hot lead flagged, a meeting booked. Activities are the queryable engagement log for your workspace, and each one embeds summaries of the contact, sequence template, and resource it touched, so you rarely need a follow-up request. A subscription that pushes activities to your endpoint as they occur, signed with HMAC-SHA256. Use webhooks instead of polling activities when you need events in near real time. An **event** is something your systems observed about a prospect and pushed to Topo. Topo turns it into a **buying signal** — a scored, ICP-filtered indicator that a contact or account is worth contacting now. Signals detected by Topo itself, such as job changes and funding rounds, sit alongside the ones you send. Activities and events point in opposite directions. An **activity** is outbound history Topo recorded and you read; an **event** is inbound intent you record and Topo reads.