River
Y CombinatorBacked by Y Combinator

LegalFree tool

Master Services Agreement and First SOW

Your proposal turned into a master services agreement on Common Paper's standard form, plus a first statement of work naming each deliverable and how it's approved.

Helpful to include

Free to start · Opens in your River workspace, ready to edit and share

How to write a master services agreement

A master services agreement (MSA) is a contract a service provider and a client sign once to set the legal terms for every project they do together. Each project then gets its own statement of work (SOW) listing the services, deliverables, schedule and fees. A good MSA settles how work is approved and paid for, who owns the results, how much either side can lose, and how projects end.

Put most of your effort into two places. The first is the statement of work, which decides when the work is done. The second is a handful of choices about who owns the work and who carries the risk.

Two men in business clothes talk over coffee at a cafe table, one holding a tablet while the other writes in a notebook
Settle what counts as done while everyone is still at the table. Photo: Vitaly Gariev on Unsplash

Start your master services agreement from a standard form

Try to send your draft before the client's procurement team sends its own, because the first draft becomes the text both sides mark up. A free standard form gets you there fast. Common Paper, a contract software company, publishes a professional services agreement1 drafted by a committee of dozens of attorneys from tech vendors, procurement teams and law firms.

You fill in its cover page once, then a statement of work for each project. The standard terms stay as published, and any change goes on the cover page, where both sides can see it.

Whatever form you use, check which document wins when the MSA and an SOW disagree. Common Paper's form lets the SOW win, so a careless SOW can override the legal terms. Have whoever negotiated the MSA read every SOW before it's signed.

Write the first statement of work

Write the SOW so a stranger could tell whether each deliverable arrived and met the bar. The Federal Acquisition Regulation, the rulebook for US federal purchasing, sets a similar test. Performance-based service contracts must include measurable performance standards2 for things like quality, timeliness and quantity, and a method for assessing the work against them.

What to write in the first statement of work

FieldWhat to writeExample
ServicesThe work, key people and milestonesDiscovery, wireframes and visual design over 12 weeks
DeliverablesEach item by name, number and formatDesigns for the 12 screens in Exhibit A, as editable files
AcceptanceDays to reject, then days to fix5 business days to reject, 10 to resubmit
Time of assignmentWhen the client becomes the ownerWhen that deliverable's fees are paid
FeesFixed, hourly or by milestone, plus expenses$84,000 fixed, in three milestone payments
Invoice and payment periodsWhen you bill, and when payment is dueAt each milestone, due 30 days after receipt
Customer obligationsWhat you need from the clientOne named approver, and site access by week 2
ExampleFrom a proposal line to a deliverableAn illustrative example written for this guide

Proposal: "Portal redesign, with unlimited revisions."

SOW: "Deliverable 2: Final designs for the 12 screens in Exhibit A, as editable design files. Includes two rounds of revisions. Further changes require a change order."

Acceptance: "Rejection Period: 5 business days from submission. Resubmission Period: 10 business days from notice of rejection."

  • Countable. Anyone can check whether 12 named screens arrived.
  • Silence is approval. Under Common Paper's terms, a deliverable not rejected in writing within the rejection period counts as approved.
  • Changes are agreed. A change order binds neither side until both agree to it in writing.

There's no late fee in Common Paper's form, and that's deliberate. In the drafting committee's experience, payment disputes were more often a customer's oversight than a deliberate act. A client that disputes an invoice must still say so within the payment period and pay the undisputed part on time. Want a late fee anyway? Add it on the cover page.

Choose when ownership passes

Under US law, copyright in a work belongs at first to its author3, usually the provider whose team made it. A transfer to the client is valid only in a writing the owner signs4. Your MSA and SOW are that writing: their wording decides what the client gets, and when.

Common Paper's form assigns the deliverables to the client and lets the SOW pick the moment. "As created" favors the client, and "upon payment" favors the provider. The drafting notes1 explain why. Withholding ownership is often a provider's only bargaining chip with a client that won't pay, while ownership that waits on payment can leave the client's title in doubt.

Carve out what the provider brought, too. Its existing tools, templates and code stay its own, and the client gets a license to them only as needed to use the deliverables. The form works this way. It also allows third-party materials, such as open-source code, only if the SOW permits them and the client approves in writing (email counts).

Buying the work? The form's SOW has an option that counts unfinished drafts as deliverables, in case the project stops early.

Set the liability cap on purpose

A liability cap limits what either side can owe the other. On Common Paper's cover page, you set the general cap as a multiple of the fees, a fixed dollar amount, or whichever is greater. The multiple, such as 1x or 2x, applies to fees paid or payable in the 12 months before the claim.

Count fees payable, not just paid. Otherwise, as the form's notes point out, a client could pay a fraction of what it agreed to and shrink the cap to match.

A blank cap means no cap

On Common Paper's form, a term left off the cover page means "none." Delete the general cap and, in Common Paper's words, "either party could be responsible for an unlimited amount of monetary damages1."

For riskier claims, such as those involving personal data, Common Paper's notes describe a trend toward a higher cap, or "supercap." Fully uncapped claims, they add, have come to be seen as hard to justify. Write the indemnification clause alongside the cap, since it covers claims from outsiders, such as someone alleging the deliverables copy their work.

The cover page can also set insurance minimums, such as errors and omissions (professional liability) cover. The US Small Business Administration describes professional liability insurance5 as protection for service businesses against losses from "malpractice, errors, and negligence." Check your policy's limits before agreeing to a minimum.

Plan how projects end

An MSA should outlast each project. Common Paper's agreement runs until 12 months after the last SOW ends, so a client who returns within that year needs only a new SOW.

The standard terms let either side end an SOW for serious trouble, such as a material breach left unfixed 30 days after notice. So does a force majeure event, such as a major earthquake, that halts the work for 30 days in a row. Neither side can walk away from a live project just because it wants to.

Put any right to cancel midway into the SOW, with a notice period and payment for work done. With no SOW active, either side can end the agreement for any reason.

Check it before you send it

Before you send the agreement

  • Each deliverable is named, with rejection and resubmission periods
  • Names, dates, fees and payment timing match the proposal
  • Ownership passes at the moment you chose, and existing tools are only licensed
  • The general cap is filled in, not left blank
  • Any subcontractors are approved in the SOW
  • Governing law and courts are named

When to bring in a lawyer

This guide is general information, not legal advice. Common Paper's terms were written with US law in mind. Have a lawyer check the draft if a party is outside the US, the fee is large, or the work is regulated or involves personal data.

If the client sends its own contract, a contract review lists what you'd commit to and the changes to ask for. When your draft comes back marked up, a redline comparison tracks every change across rounds. The tool at the top of this page fills in Common Paper's agreement and a first SOW from your proposal.

How it works

Start with your proposal, or a few lines on the work, the client and the price, and say which side you're on. River fills in Common Paper's professional services agreement in your workspace. You get the key terms cover page and a first statement of work with each deliverable, its approval windows, the fees and when ownership passes. The standard terms stay word for word.

River drafts for your side but aims for terms the other side can sign without a long negotiation. It proposes a liability cap and explains it, because a blank cap on this form means no limit at all. Any name, date or fee you didn't give is marked for you to confirm rather than guessed, and River's reply explains its key choices.

  1. Share your proposal

    Paste or attach the proposal, or describe the work, the client and the price in a few lines.

  2. River fills the form

    It completes Common Paper's cover page and a first statement of work for your side of the deal.

  3. Review its choices

    Its reply explains ownership timing, approval windows, the cap and governing law, and lists what to confirm.

  4. Edit and send it

    Change anything, add a second statement of work, redraft it for the other side or write the cover email.

What you get

  • Common Paper's professional services agreement in your workspace, with the cover page filled in for your deal
  • A first statement of work naming each deliverable, with a rejection period and a resubmission period
  • Fees, milestones, invoice timing and payment terms from your proposal, and what happens to unused retainer hours
  • Ownership timing chosen for your side, with the provider's existing tools licensed rather than handed over
  • A liability cap and governing law proposed and explained, with the cap never left blank by accident
  • Flags for personal data, subcontractors, regulated work or work abroad, and every gap marked to confirm

Common questions

What is a master services agreement?

A master services agreement is a framework contract between a provider and a client. It holds the terms shared by all their projects, such as payment rules, ownership, confidentiality, liability limits and termination. Each project is then added with its own statement of work, so the legal terms are negotiated once rather than every time.

When should I use an MSA instead of a one-off contract?

Use an MSA when you expect more than one project with the same client, or when the client's procurement team asks for one. The setup pays off from the second project, which needs only a new statement of work. For a single small job done by one freelancer, a freelance contract is simpler.

Does an MSA work for retainers and monthly work?

Yes. The statement of work can describe recurring services, such as a set number of hours or a defined scope each month, with a monthly fee and an invoice date. Say whether unused hours roll over or lapse, and how either side can end the arrangement. When you describe a retainer, River's draft says what happens to unused hours.

The client wants to use its own contract. Should I agree?

Often you'll have to, and that can be fine. Read their paper for the same decisions you'd make in yours: what counts as done, when ownership passes and how liability is capped. Offering a published standard form first helps, because the client's lawyer can confirm the standard terms are unchanged and focus on the cover page and SOW.

Is this legal advice?

No. You get a first draft on a published standard form, with its key choices explained and each gap marked. River doesn't give legal advice or say how a court would read the contract, so treat the draft as a starting point for your own review. For a large or regulated deal, have a lawyer read it before anyone signs.

How do I make a master services agreement with River?

Paste or attach your proposal in the box at the top of this page, or describe the work, the client and the price, and say which side you're on. River fills in Common Paper's agreement and a first statement of work, explains its key choices, and opens the draft in your free River workspace for you to edit.

Is the master services agreement tool free?

Yes, it is free to start. Your agreement opens in a River workspace, where you can edit it, share it with the client or your lawyer, or ask River to change it. Paid plans add more AI use and access to the most advanced models.

Sources

  1. Common Paper. “Professional Services Agreement.” commonpaper.com (opens in a new tab)

  2. Acquisition.gov. “37.601 General.” acquisition.gov (opens in a new tab)

  3. Cornell Law School. “17 U.S. Code § 201 — Ownership of copyright.” law.cornell.edu (opens in a new tab)

  4. Cornell Law School. “17 U.S. Code § 204 — Execution of transfers of copyright ownership.” law.cornell.edu (opens in a new tab)

  5. U.S. Small Business Administration. “Launch your business.” sba.gov (opens in a new tab)

Built by

Chandler Supple

Co-founder & CEO, River

Chandler has spent the last six years working in AI, building tools for millions of users and Fortune 100 companies. In 2025, he co-founded River to build a new kind of operating system for AI agents.

Reviewed by

Brian Joseff, Co-founder, River