The brain your
agents are missing.

ContextBase is context infrastructure for coding agents: features, business rules, data model, tests, design, served over MCP. Bring Claude, Cursor, or Copilot. We supply what they build from.

Connect your first agent See how it works

Works with Claude Code, Cursor, Copilot, Windsurf
Bring your own agent
Free for one project

contextbase · what you wrote

I-1Accounts

Open to agents

1F-1
Sign up with email
tests T-1, T-2
PendingIn progressImplemented
2F-2
Sign in with Google
tests T-3
PendingIn progressImplemented
3F-3
Password reset
tests T-7, T-8
PendingIn progressImplemented
4F-4
Two-factor auth
tests T-9, T-10
PendingIn progressImplemented
5F-5
Delete account
tests T-11
PendingIn progressImplemented

5 features · 11 test cases · entities User, Session, ResetToken · published

MCP

your agent · claude code, cursor, copilot

you ›Implement iteration I-1
→Claimed F-1 Sign up with email
✓F-1 built · T-1, T-2 passed · recorded
→Claimed F-2 Sign in with Google
✓F-2 built · T-3 passed · recorded
→Claimed F-3 Password reset
✓F-3 built · T-7, T-8 passed · recorded
→Claimed F-4 Two-factor auth
✓F-4 built · T-9, T-10 passed · recorded
→Claimed F-5 Delete account
✓F-5 built · T-11 passed · recorded
●I-1 complete · 5 of 5 · 11 tests green

Five features you wrote. One instruction. The agent works the list.

Why agents ship the wrong thing.

// agent wrote

if (customer.tier === 'enterprise')

Customer has no tier field

They guess your data model

A pasted doc is not a schema.

// the usual e2e test

click('Reset password')

expect(toast).toBeVisible() ✓

link expires in 15 min?
link works only once?

Tests check buttons, not rules

The click works. The business rule is never asserted.

NotionSlack threadJiraYour head

copy, paste into chat, repeat

you › “Here’s the spec again…”

The spec lives somewhere else

So you paste it into every session.

You write the knowledge. Any agent builds from it.

01You
Write the spec
Rules and test cases.
F-3 · Published
02You
Queue it
Add it to an iteration.
I-1 · step 3
03Agent
Pull it
Gets spec, schema, tests.
next_iteration_item
04Agent
Build and test
Code plus Playwright tests.
T-7, T-8 passed
05Agent
Record it
What it built, against which spec.
Implemented
06ContextBase
Watch it
Spec edits flag the record.
Outdated

One call. Everything the agent needs.

No pasting. No re-explaining.

SpecF-3 Password reset
EntitiesUser, Session
Flowreset-password
TestsT-7, T-8
Themetheme-v3

next_iteration_itemone MCP call

{
  feature:  "F-3 Password reset",
  spec:     [ 2 rules ],
  entities: [ User, Session ],
  flow:     "reset-password",
  tests:    [ T-7, T-8 ],
  theme:    "theme-v3"
}

Most tests prove the button works. Not that the rule holds.

ContextBase test cases are written as business rules. Agents turn them into code that asserts the rule.

typical e2e test

test('reset password', async () => {
  await page.click('Reset password')
  await expect(page.getByText('Email sent')).toBeVisible()
})

Passes.Checks that a toast appeared.

contextbase test case → generated test

T-7Expired link is rejected

Given: a reset link created 16 minutes ago
When: the user opens it
Then: they see “This link has expired” and no session is created

const link = await createResetLink({ ageMinutes: 16 })
await page.goto(link)
await expect(page.getByText('This link has expired')).toBeVisible()
expect(await sessions.count()).toBe(0)

Passes.Checks the business rule.

Design the look once. Agents build on-brand.

Pick colors, type, and radius. Preview live. Publish. Your agent pulls the tokens instead of guessing what “on brand” means.

contextbase · theme

Primary

#3ECF8E

Font

Inter500 / 400

Radius

4px6px8px12px

Spacing base

8px

Live preview

Reset your password

We’ll email you a link. It expires in 15 minutes.

Send link

NewBetaBack to sign in

Published as theme-v3agents read the tokens

Click anything on your live page. Change it. Your agent ships it.

Words, spacing, colors. Saved as edits your agent applies to the real code.

contextbase · page editor · yoursite.com/

yoursiteProductPricingStart

h1 · hero

Reset passwords without the support tickets.

One link. Fifteen minutes. Works once.

Start freeSee docs

Text

Reset passwords without the support tickets.

Style

Size 48 → 56

Weight 500

Saved changes

Hero headline texth1
Hero headline size56px
CTA label → “Start free”button

Save 3 changes

your agent

you › Apply the page edits

✓ Pulled 3 saved edits for /
✓ Hero.tsx · headline text and size
✓ Hero.tsx · CTA label
✓ Opened PR #42

Edits are read over MCP. The agent changes the real code, not a copy.

Order the work. Agents pull it one step at a time.

1
You order. Put features in a list.
2
Agents pull. Each agent takes the next one. Never the same one twice.
3
Board updates. Done when the agent records it.

contextbase · iterations

I-1Accounts

Open to agents

1F-1Sign up with email
Done
2F-2Sign in
Done
3F-3Password reset
In progress
4F-4Two-factor auth
Pending
5F-5Delete account
Pending

Every team has a knowledge base for humans. Nobody has one for agents.

ContextBase is the knowledge base agents read from.

Humans get

Agents get

A wiki with the rules

A pasted prompt

A data model diagram

A guess

Acceptance criteria

“Looks fine”

Everything above

With ContextBase

Who uses it.

Solo founder

Re-explains the app every session.

Agent reads it from ContextBase.

Platform team

Two agents build the same thing.

Each agent pulls a different step.

Agency

“That’s not what we agreed.”

The record shows the spec they approved.

QA lead

Test coverage lives in a spreadsheet.

Every test case shows its Playwright result.

Free for one project. One paid plan when you need more.

Free

Free forever

Scope one real project and feed it to your agent.

1 project
100 features per project
3 members per project
1 MCP token per project
Unlimited open iterations

Create free project

Premium

Coming soon

$50per year

Two months free compared to monthly. Cancel any time.

50 projects
2000 features per project
15 members per project
10 MCP tokens per project
20 open iterations