// Under the Hood · Updated March 2026

COPILOT
UNPACKED

A comprehensive deep-dive into how Microsoft 365 Copilot works — from architecture to Wave 3's latest frontier innovations.

⚡ Wave 3 · GPT-5.3/5.4 · Cowork · Agent 365 · Work IQ · Claude
↓   SCROLL TO EXPLORE


// 01. Overview

What Is Copilot?

Microsoft 365 Copilot is the AI system embedded across Microsoft 365 — Word, Excel, Teams, Outlook, and beyond. It combines state-of-the-art language models with your organisation's data through Work IQ and Microsoft Graph, within your security and compliance boundaries. Wave 3 (March 2026) transforms it from conversational assistant to autonomous agent capable of multi-step, multi-hour work.

Aug 2025GPT-5 GA in Copilot Chat
Nov 2025Ignite: Office Agents, Agent 365 preview
Dec 2025GPT-5.2, Sales Agent, Claude Sonnet 4.5
Mar 3 2026GPT-5.3 Instant in Copilot
Mar 7 2026GPT-5.4 Thinking lands
Mar 9 2026Wave 3: Cowork Frontier + Work IQ + Edit with Copilot
Mar 30 2026Cowork Frontier · Critique


// 02. Architecture

How a Prompt Flows

Every Copilot interaction passes through a multi-stage orchestration pipeline. Semantic Kernel routes each request through safety filters, Work IQ retrieval, model selection, and response delivery. Wave 3 adds Cowork's task-plan execution layer for long-running work.

01

User Prompt

Natural language input from Word, Excel, Teams, Outlook, or the new Cowork canvas. With Wave 3, prompts can describe multi-step outcomes that run for minutes or hours — not just single-turn questions.

Natural LanguageM365 App SurfaceWave 3: Cowork Canvas
02

Pre-Processing & Safety

Content safety filters run, PII is detected and masked, and Conditional Access + entitlement checks validate the user. Enterprise Data Protection policies apply before any data retrieval begins.

Content SafetyPII DetectionCA + EDP Check
03

Work IQ & Graph Retrieval

Work IQ — Microsoft's intelligence layer — synthesises signals across emails, meetings, chats, files, and contacts. The Semantic Index (vector-based) retrieves the most relevant chunks, permission-scoped to the signed-in user only.

Work IQSemantic IndexPermission-scopedWave 3: Full org context
04

Prompt Grounding & Context Assembly

The raw prompt, retrieved Graph content, active document, conversation history, and system instructions are assembled into a grounded prompt. For Cowork tasks, a structured task plan and checkpoint instructions are also included.

RAG GroundingContext WindowTask Planning (Cowork)
05

Model Selection & Inference

Semantic Kernel selects the optimal model — GPT-5.3 Quick Response, GPT-5.4 Think Deeper, Claude Sonnet 4.5, or others. GPT-5's real-time router auto-selects Instant vs Thinking per prompt. All (Azure OpenAI/ GPT) inference runs inside Microsoft's Azure tenant with zero data leakage to public APIs.

GPT-5.3 / 5.4Claude Sonnet 4.5Azure OpenAIAuto Model Routing
06

Post-Processing & Delivery

Output passes through a second safety filter, formatted for the target app, delivered with citations. For Cowork, the orchestrator executes the next action in the task plan, checks back at configured checkpoints, and continues — audited at every step via Purview.

Output SafetyCitationsCheckpoint ExecutionPurview Audit


// 03. Live Simulation

Prompt Pipeline

Select a scenario and run the pipeline to see how Copilot orchestrates each stage — including a Cowork multi-step scenario.

copilot.pipeline.sim — Microsoft 365 Copilot · Wave 3
📧 Summarise emails
📊 Analyse data
🔬 Researcher brief
🏗️ Cowork multi-step
YOU
Summarise my unread emails from this week and highlight any action items.
✏️
INPUT
Prompt
🛡️
SAFETY
Pre-filter
💡
WORK IQ
Graph
📐
GROUND
Context
🧠
MODEL
Inference
OUTPUT
Deliver
Click "Run Pipeline" to simulate Copilot's response…


// 04. Context Window

What Goes In?

The grounded prompt sent to the LLM is a carefully assembled package. Wave 3 expands context with richer Work IQ signals and Cowork task state.

Context Window Composition — approximate token allocation
System Instructions & Safety Rules~7%
Work IQ Signals (Graph: emails, chats, meetings)~42%
Active Document / App Context~28%
Conversation & Cowork Task History~16%
User's Raw Prompt~7%


// 05. Data Grounding

Where Does Data Come From?

Copilot grounds responses in your organisational data — retrieved in real time, scoped to the signed-in user's permissions. Wave 3 added Dynamics 365 and Power Apps as native grounding sources.

✉️ Outlook & Email

  • Unread & flagged emails
  • Sent mail for tone matching
  • Calendar invites & attendees
  • RSVPs & scheduling context

💬 Teams & Chats

  • Channel conversations & threads
  • Meeting transcripts (if enabled)
  • 1:1 chat messages
  • Shared files in chat

📁 SharePoint & OneDrive

  • Documents, decks, spreadsheets
  • Shared with me files
  • Version history context
  • Site pages and wikis

🔌 Plugins, CRM & Apps

  • Salesforce, ServiceNow, Jira, Confluence
  • Dynamics 365 & Power Apps (Wave 3)
  • 1,400+ systems via MCP & Graph
  • Third-party agents in Agent Store
🔒

Permissions-Scoped Access

Copilot only surfaces content the signed-in user already has permission to see. SharePoint permissions, Purview sensitivity labels, DLP policies, and Conditional Access are all respected. If a file is restricted, Copilot won't retrieve it — even for Cowork tasks. All Cowork actions are fully auditable via Microsoft Purview.



// 06. Orchestration

Semantic Kernel Orchestrator

Copilot isn't a single LLM call. The Semantic Kernel orchestration layer decides which models, skills, plugins, and data sources to invoke. In Wave 3, it also coordinates Cowork tasks running across apps over extended periods.

🧠
SEMANTIC KERNEL · WAVE 3 ORCHESTRATOR
📧Outlook
Copilot
💬Teams
Skill
📄Word
Agent
📊Excel
Agent
🎨PPT
Agent
🔬Researcher
📈Analyst
⚙️Workflows
🏗️Cowork
🔍Web
Search
🔌MCP
Plugins
🤖Custom
Agents


// 07. Core Capabilities

What Copilot Can Do

✍️
Draft & Rewrite
Generate emails, documents, and presentations from a brief. Wave 3: edits directly in the native app canvas, grounded in Work IQ context so content always reflects current state.
📋
Summarise
Teams meeting recaps, email thread summaries, document overviews. Copilot Notebooks generate audio overviews — podcast-style briefings for catching up on the go.
🔍
Search & Retrieve
Ask natural language questions across all M365 data. "What did we decide about Project X last week?" draws on emails, chats, docs, and meetings — permission-scoped.
📊
Analyse Data
Excel Agent builds models and charts. Analyst runs Python, detects patterns, generates visualisations. Code is transparent and verifiable in real time — from raw data to insight in minutes.
🎨
Create Presentations
Turn a Word doc or Copilot Page into a full PPT deck. Brand templates, speaker notes, and contextual explanations on any slide element — right-click → Explain.
🏗️
Long-Running Work (Cowork)
Wave 3: Delegate multi-step, multi-hour tasks. Cowork breaks goals into plans, executes across apps, pauses at checkpoints, and delivers auditable outputs powered by Anthropic's Claude.


// 08. Model Choice

The Model Timeline

Microsoft's multi-model architecture means Copilot is never locked to one provider. Here's how the model roster evolved from GPT-5 through to the March 2026 frontier — including Anthropic's Claude.

AUG 2025
GPT-5 & GPT-5 Reasoning
GPT-5 launched in Copilot on day of release. A real-time router chose between a fast chat model and a deep reasoning model automatically based on prompt complexity. Also available in Copilot Studio for agent orchestration.
Copilot ChatStudio AgentsAuto-routing
🟣
OCT–NOV 2025
GPT-5.1 + Claude Sonnet 4.5 (Beta)
GPT-5.1 became default for declarative agents with auto model selection. Anthropic's Claude Sonnet 4.5 arrived in beta in Copilot Studio for Computer Use agents — enabling autonomous browser and GUI control.
Declarative AgentsClaude Sonnet 4.5Computer Use (Beta)
💡
DEC 2025
GPT-5.2 Instant & Thinking
GPT-5.2 became the default model in Copilot Chat. Introduced dual-mode architecture: Instant for fast everyday tasks, Thinking for complex strategic analysis. Dramatically improved coding, math, multilingual capabilities, and extended context handling.
Quick ResponseThink DeeperDefault Model
🚀
MAR 3, 2026
GPT-5.3 Instant — "Quick Response"
More accurate everyday responses with stronger, more expressive writing and fewer unnecessary disclaimers. Better web synthesis — Copilot now combines online sources with its own reasoning for directly usable outputs. Appears as "GPT-5.3 Quick response" in the model selector; "GPT-5.3 Chat" in Copilot Studio.
Quick ResponseGA · Mar 3, 2026Better Web Synthesis
🧠
MAR 7, 2026
GPT-5.4 Thinking — "Think Deeper"
Strengthens Copilot's ability to reason, plan, and work through complex multi-step tasks with less back-and-forth. When paired with Work IQ, becomes noticeably more context-aware across your organisation. Handles technical prompts and longer workflows with higher-quality outputs. "GPT-5.4 Think deeper" in Copilot Chat; "GPT-5.4 Reasoning" in Copilot Studio.
Think DeeperStudio ReasoningWork IQ Integration
🤝
MAR 30, 2026
Claude + GPT "Critique" in Researcher
A new capability where GPT drafts a response to a research query and Claude reviews it for accuracy, completeness, and citation quality before delivery. Multi-model advantage in action — two frontier AI systems collaborating on a single output. Copilot Cowork also uses Anthropic's Claude for multi-step reasoning via its agentic harness.
GPT Drafts · Claude CritiquesResearcher AgentCowork Reasoning
// Model selector — Copilot Chat (March 2026)
⚙️ Auto
⚡ GPT-5.3 Quick
🧠 GPT-5.4 Think Deeper
💡 GPT-5.2 Think Deeper
🟣 Claude Sonnet 4.5
⚙️ Auto — Copilot routes your prompt to the best model automatically: GPT-5.3 for quick tasks, GPT-5.4 for complex reasoning


// 09. Work IQ

The Intelligence Layer

Work IQ is the intelligence layer that gives Copilot and agents full knowledge of how you work, with whom you work, and the content you collaborate on. It's what separates Copilot from a generic model-plus-connector solution.

Work IQ amplifies your individual intelligence by tapping into your organisation's collective knowledge. It continuously synthesises signals across all M365 services, building a rich real-time context model that powers Copilot's responses, personalises outputs, and lets Cowork act with the same understanding you bring to your job.

Without Work IQ, an AI model only sees what you paste into a prompt. With Work IQ, Copilot knows the full history of a project — who said what in which meeting, what decisions were made in emails, which documents are most relevant, and what the current state of your work actually is.

🗂️ Knowledge Graph

Maps relationships between people, projects, documents, and decisions across your entire M365 estate in real time.

⏱️ Temporal Context

Understands the sequence and recency of work — what's current, what's stale, and what's upcoming.

👥 People Signals

Knows who you collaborate with most, who owns what, and who the key stakeholders are for any project.

🔄 Real-Time Updates

Refreshes continuously — so Copilot and Cowork always reflect the current state of your files, meetings, and chats.

Signal Sources — Work IQ Ingestion
Outlook / Email
88%
Teams / Chats
82%
SharePoint / Docs
76%
Calendar
64%
Dynamics 365
48%
Power Apps
38%


// 10. Agent 365

The Agent Control Plane

Agent 365 is the enterprise control plane for AI agents — the single place IT and security leaders use to observe, govern, secure, and manage every agent across the organisation. In just two months of preview, tens of millions of agents appeared in the registry.

👁️ Observe

Centralised visibility of all agents — Microsoft first-party, third-party, and custom — in a single inventory. Monitor agent activity, usage patterns, and agent-to-agent interactions via the Agent 365 registry.

⚖️ Govern

Set policies for which agents can run, which data sources they can access, and what actions they can take autonomously. Approval workflows for sensitive agent actions before execution.

🛡️ Secure

Powered by Defender, Purview, and Entra Agent ID. Agents get Entra identities, can be phishing targets, and are protected with the same security infrastructure as human users. "AI agents are as subject to phishing attacks as people are."

⚙️ Manage

Full lifecycle management: deploy, update, disable, or retire agents at scale. Integrated with Intune, Defender, and Purview for compliance and audit support across all agent actions.

Agent 365 — Spec Sheet

📅
General AvailabilityMay 1, 2026 · Announced at Wave 3 on March 9, 2026
🪪
Entra Agent IDEvery managed agent gets a Microsoft Entra identity — the same IAM controls used for humans apply to AI agents
🔒
Defender + Purview IntegrationReal-time protection, audit logging, DLP enforcement, and sensitivity label compliance for all agent actions
🔢
ScaleTens of millions of agents registered in just two months of preview. IDC predicts 1.3B enterprise agents by 2028
🌐
Multi-Agent OrchestrationAgents can orchestrate other agents. Agent 365 tracks the full chain of agent-to-agent interactions for auditability

💰 PRICING

Agent 365: $15 / user / month standalone · Or included in M365 E7 Frontier Suite at $99/user/month


// 11. Reasoning Agents

Researcher & Analyst

Two purpose-built reasoning agents — GA for all M365 Copilot licence holders since June 2025. Researcher now orchestrates other agents, and both are deeply integrated with Work IQ. March 2026: Researcher adds GPT + Claude "Critique" for accuracy validation.

🔬
Researcher
OpenAI Deep Research Model · GA Jun 2025

Multi-step research at work. Combines OpenAI's deep research model with M365 Copilot's orchestration and Graph search. Integrates third-party data from Salesforce, ServiceNow, Confluence, Jira, and more. Can call other agents for specialised sub-tasks. March 2026: GPT drafts, Claude critiques research outputs.

  • Comprehensive competitive analyses and board-level briefs
  • Vendor negotiation prep with internal + web data
  • Multi-agent orchestration — Researcher calls other agents
  • Custom source controls (toggle work, web, third-party)
  • New: GPT + Claude "Critique" for accuracy validation
"Build a go-to-market strategy grounded in our internal work data and competitive web intelligence"
📊
Analyst
OpenAI o3-mini · GA Jun 2025

Thinks like a skilled data scientist. Uses chain-of-thought reasoning to progress iteratively through analytical problems. Runs Python in real time — code is visible, verifiable, and auditable. Outputs feed directly into Researcher for integrated qualitative + quantitative insights.

  • Raw data → insights and visualisations in minutes
  • Pattern detection, outliers, and statistical analysis
  • Python execution with transparent, viewable code
  • Complex multi-step queries and forecasting models
  • Seamlessly feeds insights into Researcher
"Find the top 3 revenue trends in this dataset and explain the regional outliers with charts"


// 12. Copilot Notebooks

Living Project Workspaces

Notebooks are persistent, AI-powered workspaces. Instead of context scattering across emails, chats, and documents, Notebooks aggregate all project content — with AI reasoning applied continuously. Available on desktop, web, and the Copilot mobile app.

SOURCES
📄 Project Brief v3.docx
📧 Stakeholder emails (14)
💬 Teams thread — Architecture
🔗 Competitor website link
🎙️ Kickoff meeting recording
+ Add source…
PAGES
📓 AI Summary
🎧 Audio Overview
📑 Copilot Page export
Azure Migration — Project Notebook
🧠 AI Summary

Based on all 5 sources, the project is in Phase 2 (Identity migration). Key risk: 3 legacy apps not yet remediated. Stakeholder sentiment is positive with concern around the March 28 cutover. Notebook will update this summary as new content is added.

🎧 Audio Overview

Generates a podcast-style audio briefing — two AI hosts walking through key points. Customisable narration style and length. Available in OneDrive, Outlook, Teams, Word, and the Copilot mobile app.

📱 Mobile (iOS + Android)
🎧 Audio overviews
📄 Docs + emails + chats
🔗 Web links as sources
🔄 Persistent context
📑 Copilot Pages export
🎙️ Meeting recordings
🔬 Researcher integration


// 13. Office App Agents

Word, Excel, PowerPoint & Outlook

Wave 3 embeds Copilot natively in Word, Excel, PowerPoint, and Outlook — turning document creation from a blank-page task into an iterative, conversational collaboration, grounded in Work IQ context at all times.

W
Word Agent
Wave 3 GA · Mar 2026

Agent Mode turns document creation into an interactive dialogue inside the canvas. Copilot drafts, suggests refinements, asks clarifying questions, and applies native Word styles — grounded in Work IQ.

  • Conversational creation from a brief
  • In-context Q&A and iterative refinement
  • Grounded on SharePoint, emails, meetings
  • Native styles, no formatting needed
X
Excel Agent
Wave 3 GA · Mar 2026

Plans, executes, and validates multi-step tasks directly in the grid. Inserts real Excel formulas and structures. Every change is transparent, auditable, and reversible. "It speaks Excel."

  • Multi-step planning and execution in grid
  • Real Excel formulas and native structures
  • Validates its own outputs before presenting
  • Natural language to formula — no syntax needed
P
PowerPoint Agent
Wave 3 GA · Mar 2026

Full decks from a Copilot Page, Word doc, or brief. Brand templates, speaker notes, and contextual explanations on any element. Right-click any object → "Explain" for full context.

  • Deck creation from Word docs or Copilot Pages
  • Brand template application
  • Right-click "Explain" on any slide object
  • Speaker notes grounded in Work IQ
O
Outlook Copilot
Wave 3 GA · Mar 2026

Draft and refine emails, manage calendars and RSVPs. Copilot finds available meeting times, sends invites, and keeps calendars up to date — all via natural language in the chat sidebar.

  • Email draft and rewrite in context
  • Natural language meeting scheduling
  • Calendar management and RSVP handling
  • Conflict detection and time suggestions


// 14. Copilot Cowork

Beyond Prompts: Long-Running Work

Cowork is the headline feature of Wave 3. It transforms Copilot from a chat assistant into an autonomous agent that executes multi-step, multi-hour tasks across your entire M365 environment — with transparent checkpoints, enterprise governance, and Anthropic's Claude powering its reasoning.

How Cowork Executes

1
Describe an Outcome

State a goal, not a single task. E.g., "Prepare the Q1 board presentation using SharePoint reports, Teams transcripts, and the Excel financial model."

2
Cowork Creates a Plan

Breaks the goal into discrete steps, identifies M365 resources to access, and presents the plan for your review before starting execution.

3
Background Execution

Cowork works across Outlook, Teams, SharePoint, Word, Excel, and PowerPoint simultaneously — reading emails, analysing transcripts, pulling data, generating deliverables.

4
Checkpoints Keep You in Control

At predefined intervals, Cowork pauses, shows progress, requests confirmation on sensitive actions, and allows you to redirect or halt work at any time.

5
Auditable Delivery

All Cowork actions are logged in Microsoft Purview. Outputs are native M365 artifacts — version-controlled and governed by your existing DLP, sensitivity label, and compliance policies.

🏗️ Copilot Cowork (Microsoft)

Runs in the cloud within your M365 tenant. Covered by Enterprise Data Protection. Powered by Work IQ for full org context. Uses Anthropic's Claude model for multi-step reasoning and the same agentic harness as Claude Cowork — but enterprise-grade, cloud-based, fully auditable. Available in Frontier from March 30, 2026.

🖥️ Claude Cowork (Anthropic)

Runs locally on a user's device. Anthropic's standalone agentic product. Microsoft's Cowork is built on the same agentic platform but runs in the cloud with M365 governance and Work IQ integration. "We actually don't work locally, and that's a feature, not a bug." — Jared Spataro, Microsoft

⚠️ Governance Before Enabling

Cowork accesses data across multiple M365 services in a single workflow. Ensure permissions models are airtight, configure Purview audit logging for Cowork events, and define which actions require human approval before enabling in production.

🤝

Built with Anthropic

Copilot Cowork is built in close collaboration with Anthropic, bringing the technology platform that powers Claude Cowork into Microsoft 365 Copilot. It uses Claude as the AI powering multi-step reasoning — but runs enterprise-grade in your M365 tenant with Work IQ and Enterprise Data Protection. The broader Copilot multi-model strategy also includes Claude Sonnet 4.5 for Computer Use agents and the new GPT + Claude Critique capability in Researcher. "We have the ability to reach across the industry and look at innovations coming from OpenAI, from Anthropic, and bring them into this system." — Jared Spataro, Microsoft CMO AI@Work



// 15. Agent Roster

The Full Agent Store

Microsoft's Agent Store has grown into a full ecosystem. First-party, third-party, and custom agents are all discoverable, pinnable, and governed via Agent 365 — with new agents added continuously through the Frontier programme.

🔬
Researcher
GA · Jun 2025

Deep research across work + web. Board briefs, competitive analyses, client prep. Orchestrates other agents. New: GPT drafts, Claude critiques (Mar 2026).

📊
Analyst
GA · Jun 2025

Runs Python, detects patterns, generates charts. Built on o3-mini. Raw spreadsheet → executive insight in minutes. Code is transparent and verifiable.

🏗️
Copilot Cowork
Frontier · Mar 2026

Long-running, multi-step task execution. Breaks goals into plans, runs across M365, checks in at configurable checkpoints. Powered by Claude + Work IQ.

💼
Sales Development Agent
Frontier · Dec 2025

Autonomously builds pipeline, nurtures leads, personalises outreach. Connects to Salesforce and Dynamics 365. Sellers focus on closing; agent handles prospecting.

⚙️
Workflows Agent
Frontier · Oct 2025

Automates repetitive tasks across M365 apps using simple prompts — meeting summaries, task digests, scheduled triggers. Enterprise-grade security built in.

🧑‍💻
Skills Agent
GA · 2025

Powered by People Skills data layer. Builds dynamic skill-based teams and helps employees discover colleagues with specific expertise across the organisation.

📋
Surveys Agent
GA · Oct 2025

Personal survey expert. Gathers training feedback, measures employee sentiment, runs customer research. Describe what you want to learn — no survey builder expertise needed.

🤖
Custom Agents (Studio)
GA

Build agents connected to 1,400+ systems via MCP, Power Platform, and Graph. Multi-agent orchestration. Computer Use via Claude Sonnet 4.5. Governed by Agent 365.



// 16. M365 E7 — Frontier Suite

Intelligence + Trust, Unified

Announced March 9, 2026, Microsoft 365 E7 bundles E5 + Copilot + Agent 365 + the full security stack into a single Frontier Suite — at a price below buying them individually. More than 90% of the Fortune 500 now use Microsoft 365 Copilot.

E7

Microsoft 365 E7 — The Frontier Suite

Announced March 9, 2026 · E5 + Copilot + Agent 365 + Entra + Defender + Intune + Purview in one solution

💼
M365 E5
Full E5 productivity, compliance, and voice — the complete Microsoft 365 enterprise baseline.
M365 Copilot
Full Copilot licence including Wave 3 agents, Cowork, Researcher, Analyst, Notebooks, and Work IQ.
🤖
Agent 365
Enterprise agent control plane — observe, govern, secure, and manage all agents across the org.
🪪
Entra Suite
Full identity and access management including Entra Agent ID for AI agent identities.
🛡️
Defender
Advanced threat protection including for agent identities and autonomous agentic actions.
📱
Intune
Device and endpoint management, extended to agent-operated and Cowork environments.
⚖️
Purview
Compliance, audit logging, and data governance — including for Cowork actions and agent outputs.
PER USER / MONTH · Below à la carte cost
$99 / user