For GTM engineers building on ChatGPT + Codex

Customer Memory and Harness for Building GTM Agents

You've connected ChatGPT to your CRM, Gong, and Gmail via MCP, and built automations in Codex. You can keep building — persistent memory, shared context, governance. But each one is bespoke infrastructure you own and maintain, not a multiplayer platform.

Day is that platform, already running: every call, email, and Slack thread pre-processed into a graph built for agent retrieval, plus deployable skills, per-user permissions, and shared team context. Connect it via MCP. Keep building GTM.

What This Means for Your Sales Team

You can build all of this on ChatGPT + MCP yourself. Day is the platform that already has — running in production, shared across your team.

Capability

DIY

ChatGPT + MCP + CRM

Day

Memory + Harness

MultiplayerGovernedProduction-ready

Context retrieval

Re-discovers from scratch every time — slow, token-heavy

Pre-processed graph — instant, token-efficient

Automation

Possible in Codex, but you build and maintain every workflow — no shared deployment, no audit trail

Event-driven and scheduled skills out of the box — deploy across the team with built-in governance

Team context

Single-player by default — shared context requires building custom infrastructure

Multiplayer by design — shared memory across the org

Governance

You can build shared conventions, but can't enforce them — no centralized visibility, drift across reps is inevitable

Workspace-level skill deployment with permissions, audit trails, and centralized management

Composability

Can integrate with any surface, but each integration is custom-built and maintained

Ready-made MCP server, SDK, and Slack integration — access the memory layer from wherever your team already works

Data accuracy

Inherits CRM data quality problems — stale fields degrade agent output

Memory captures ground truth from every interaction automatically

Revenue impact

Real gains, but capped by the engineering effort to build and maintain the infrastructure

Purpose-built platform delivers compound returns without custom engineering

DayAI

Work complete. Processed call and cross-referenced account memory

Built by the Team That Built HubSpot CRM

Day was founded by the original builders of HubSpot CRM. We spent a decade learning what works — and what breaks — when you try to make humans maintain a system of record. We built Day on the conviction that the next generation of GTM infrastructure shouldn't require humans to do data entry at all. The system should remember everything and act on it — so your team can focus on what actually moves deals forward.

Backed by Sequoia Capital. Used by GTM teams replacing and augmenting HubSpot, Salesforce, Pipedrive, Gong, and Affinity.

You're Already Building This. We've Already Built It.

Every GTM team we talk to is trying to solve this problem. The question isn't whether you need persistent customer memory and an agent harness — it's whether you want to build it yourself or start with a foundation that's already running in production.

Book a demo to see how Day's Customer Memory Graph and Agent Harness work together — and how they fit into the architecture you're already building.

Book a demo

What This Means for Your Sales Team

You can build all of this on ChatGPT + MCP yourself. Day is the platform that already has — running in production, shared across your team.

Capability

DIY

ChatGPT + MCP + CRM

Day

Memory + Harness

MultiplayerGovernedProduction-ready

Context retrieval

Re-discovers from scratch every time — slow, token-heavy

Pre-processed graph — instant, token-efficient

Automation

Possible in Codex, but you build and maintain every workflow — no shared deployment, no audit trail

Event-driven and scheduled skills out of the box — deploy across the team with built-in governance

Team context

Single-player by default — shared context requires building custom infrastructure

Multiplayer by design — shared memory across the org

Governance

You can build shared conventions, but can't enforce them — no centralized visibility, drift across reps is inevitable

Workspace-level skill deployment with permissions, audit trails, and centralized management

Composability

Can integrate with any surface, but each integration is custom-built and maintained

Ready-made MCP server, SDK, and Slack integration — access the memory layer from wherever your team already works

Data accuracy

Inherits CRM data quality problems — stale fields degrade agent output

Memory captures ground truth from every interaction automatically

Revenue impact

Real gains, but capped by the engineering effort to build and maintain the infrastructure

Purpose-built platform delivers compound returns without custom engineering

DayAI

Work complete. Processed call and cross-referenced account memory

Built by the Team That Built HubSpot CRM

Backed by Sequoia Capital. Used by GTM teams replacing and augmenting HubSpot, Salesforce, Pipedrive, Gong, and Affinity.

You're Already Building This. We've Already Built It.

Book a demo to see how Day's Customer Memory Graph and Agent Harness work together — and how they fit into the architecture you're already building.

Book a demo

Trusted by founders at B2B companies

“My Day AI assistant reminded me about a prospect since it had been 9 days since our demo. I followed up and now the deal is advancing. I wouldn't have followed up today if I hadn't received the nudge, because it had been buried in my deal pipeline.”

Simon Kronenberg

Co-founder & CRO, Digit

“I love Day AI. I can count at least 10+ times where it's sent me reminders in Slack to chase a lead I would've forgotten about and would not have closed without them.”

Nathan May

Founder, The Feed Media

“Day AI captures the connective tissue that usually disappears. That's what lets us build agents with substance, tasks with real understanding, outbound that knows the full journey.”

Christopher Booth

Founder & CEO, Charm