Development agency
Best for enterprise middleware, legacy systems, many integrations at once.
A scoped project with a team and a timeline. Four to eight weeks for a focused custom API, per one agency's own page.
- Price
- $15k–$35k+
- Decides
- The agency
API integration
API integration services: what they cost, and what makes one work
You need two tools to talk to each other. Most quotes price the connection. The expensive part is the day an event arrives twice, and the brief that says what should happen when it does.
● ScopedAPI integrationHubSpot → Stripe
Deal won in HubSpot → draft invoice in Stripe
Built by Pond against this brief
- The trigger and the result
- Deal marked won → one draft invoice, for the deal amount, to the primary contact.
- The tests it must pass
- Same event twice → one invoice. Stripe down 1 hr → retried. Rate limit → waits.
- What is out of scope
- Live credentials, historical invoices, ongoing monitoring.
- How it is priced
- A quote for this scope, agreed on a call before the build starts.
Price
Quoted after a scope call
Build checklist5Checked before handover
- 1Done
Scope call
Trigger, field map and failure cases agreed
- 2Done
Build · Node + webhook queue
Runs on test accounts
- 3Done
Test · same event twice
One invoice
- 4Done
Test · Stripe down 1 hr
Retried, nothing lost
- 5Your review
Handover
Code, readme, test run recording
Illustrative build, written from the brief checklist on this page.
Short answer
A focused API integration costs anything from a few hundred dollars to tens of thousands, depending on who builds it. Upwork's hire page puts a single integration at $150 to $500. One development agency, Imaginovation, quotes $15,000 to $35,000 for standard third-party integrations. Zapier starts at $19.99 a month if both apps already have a connector. The spread is less about skill than about how precisely you can say what "working" means.
One job, five price tagsLog scale, US dollars
- Upwork hire page · $150–$500
- Upwork project · $500–$1,500
- Agency · $15k–$35k
- Agency, complex · $50k+
$10$100$1,000$10,000$100,000
Not per project: Zapier from $19.99 a month, Make from $9 a month (read 15 Oct 2026). In-house: $134,040 a year, the 2025 BLS median for software developers. Upwork hire page read 15 Oct 2026; Upwork project page 30 Sept 2026; Imaginovation 15 Oct 2026.
Four ways to get an integration built
None of these is the right answer for everyone. The section on when Pond is the wrong call is further down, and it is the honest part.
Hire an API developer
Best for a developer you will keep working with.
You post a job, read proposals, hire one person and manage the build. Upwork's rate card reads $20 to $40 an hour at the median.
- Price
- $150–$2,000
- Decides
- You
Automation tool
Best for simple triggers between apps that already connect.
You build it yourself in Zapier, Make or n8n. It can be live the same day. Per-task pricing grows with the volume.
- Price
- $9–$20 / mo
- Decides
- You
Have Pond build it
Best for one integration you can describe as a test.
You send the brief. Pond scopes it with you on a call, quotes, builds it and hands it over with the test run. This is Pond.
- Price
- Quoted per scope
- Decides
- You
What does API integration cost?
Six routes, and almost as many units of price. None of these is an industry average. Each is one source's number, on the day it was read.
What one integration costs, by route
Automation tool, a month$9–$20
Upwork, single integration$150–$500
Upwork, custom API with database$2k–$6k
Agency, standard$15k–$35k
Agency, enterprise middleware$50k+
$10$100$1k$10k$100k
Pond builds it
A quote for your scope, agreed on a call
Quotebefore any build starts
| Route | Published price | Source, read |
|---|---|---|
| Freelancer marketplace | $20–$40 an hour, median. $150–$500 for one integration; $500–$2,000 for an app's API | Upwork, 15 Oct 2026 |
| Curated developer network | $60 to $100 or more an hour | Arc.dev, 30 Sept 2026 |
| Development agency | $15,000–$35,000 standard; $50,000–$100,000+ for enterprise middleware | Imaginovation, 15 Oct 2026 |
| Automation tool | Zapier from $19.99 a month. Make from $9 a month | Vendor pages, 15 Oct 2026 |
| In-house engineer | $134,040 a year, the 2025 median for software developers | U.S. Bureau of Labor Statistics |
| Pond builds it | A quote for your scope, agreed on a call before the build | Pond |
Prices are each provider's own published figures. None of them is a quote for your integration.
The systems buyers name most
n8n229
OpenAI177
Zapier171
Make167
Claude140
Shopify137
Supabase136
Stripe100
What do people actually hire for?
We read the 1,706 Upwork postings tagged API Integration on 14 September 2026. It is not beginner work, almost half now involve an AI model, and one in five pays someone to build inside n8n, Zapier or Make.
$300
median fixed price, against $100 marketplace-wide
98%
ask for an intermediate or expert developer
44%
name an AI model such as OpenAI or Claude
Real fixed-price postings, as buyers wrote them
- HubSpot to Slack notifications workflow automation$500
- Salesforce – WooCommerce integration$200
- AI missed-call reminder (n8n/Make, Twilio, OpenAI)$600
Upwork, 108,082 postings published 14 Sept 2026, 1,706 carrying the API Integration tag. A posting can name several systems.
Why is the range so wide?
Four things move the number. A quote that does not separate them is pricing an undefined object.
How many systems it touches
One job that reads a form and writes a row is small. A two-way sync where both sides edit the same record is a different project with the same name.
How the other side lets you in
OAuth 2.0 defines several grant types. Which one the vendor supports, and whether tokens expire, decides a surprising share of the build time.
How much traffic it carries
Every serious API limits requests. An integration that ignores the 429 and its Retry-After works in the demo and fails on the busiest day of the month.
Who watches it afterwards
APIs change fields, retire versions and rotate keys. An integration nobody watches keeps running while it quietly drops records.
Custom, pre-built or hybrid?
Four questions, in this order. The first one you answer yes to decides it.
Your answerQuestion 4 of 4
1Use the automation toolNo
2Tool plus one custom stepNo
3Hire an agencyNo
4Send the brief to PondYes
An integration is one of the easiest things to specify
Most software is hard to specify because "good" is a matter of taste. An integration is not. It moves the right data, at the right time, and survives the failure cases, or it does not. The vendors document the failure cases themselves, so you can write them into the brief as tests.
Stripe tells developers not to depend on receiving events in a specific order, and to track event IDs to catch duplicates.
Test run · Build #44 of 4 passed
- Pass
Same event delivered twice → one record
evt_1Q9 ×2 → invoice count 1
Stripe: track event IDs to catch duplicates
- Pass
Same request retried → one object
Idempotency-Key: k_77 ×2 → 1 invoice
Stripe: idempotency keys
- Pass
Push past the rate limit → nothing lost
429 · Retry-After: 30 → waited, 0 lost
OpenAI: treat a retry delay as a minimum
- Pass
Create the record → appears within 5 minutes
webhook received 2.1s → invoice draft
Shopify: webhooks over polling
How to write an integration brief anyone can quote against
Five parts. Write them before you ask anyone for a price, and every quote you receive becomes comparable.
Most integration disputes are field-mapping disputes that nobody wrote down. Whichever route you choose, this is the part to write yourself.
1The trigger and the result, in one sentence
Not "connect HubSpot to our billing tool". A usable version: when a deal is marked won in HubSpot, a draft invoice exists in Stripe within five minutes, for the deal amount, to the deal's primary contact.
2The field map
dealname → invoice title · amount → invoice total · contact email → bill to if empty: hold and alert
3The failure cases
The same event twice. Events out of order. The destination down for an hour. A rate limit hit. One sentence of expected behaviour for each.
4The evidence
A recording or log of the test run on test accounts, the code or exported workflow, and a short readme on changing a credential.
5What is out of scope
Historical data migration, ongoing monitoring, and anything touching production credentials, unless you say otherwise.
- + Failure-case tests attached
Quick picks
| Route | Development agency | Hire an API developer | Automation tool | Pond builds it |
|---|---|---|---|---|
| Best for | enterprise middleware, legacy systems | a developer you keep working with | simple triggers between connected apps | one integration you can describe as a test |
| What comes back | a delivered system and an account manager | one person's version | whatever you build | a working integration and its test run |
| You pay for | the project, weeks to months | hours or a fixed price | a monthly plan | a quote for your scope, agreed on a call |
| Who decides it works | the agency's project lead | you, after the hire | you | you, at handover |
Prices are the providers' own published rates. None of them is a quote for your integration.
When Pond is the wrong call
Some integration work is better bought somewhere else, and saying so is more useful than pretending otherwise.
When both apps already connect
If Zapier, Make or n8n has a connector for both sides and the logic is simple, build it yourself the same day. You do not need to pay anyone for it.
When you need a developer on staff
An integration you will change every month is an ongoing relationship. Hire the person.
When you cannot write down what done looks like
If the requirements will be discovered by building, there is nothing yet to quote. Pay for the discovery first.
When it is really a system migration
Moving a company from one ERP to another is a program of work with a steering group. That is agency work.
If the job is only a CRM sync, what a CRM integration job includes, what it costs, and how to judge it covers it in more detail. If you would rather pay someone to build it in an automation tool, see what a Zapier expert, n8n consultant or Make developer costs. If the integration puts an AI model in the middle, read what generative AI integration costs, and how to connect an AI agent to your CRM and help desk before it gets write access.
Frequently asked questions
How much does API integration cost?
It depends on the route. Upwork's hire page puts a single integration at $150 to $500 and an app's API at $500 to $2,000. Imaginovation, a development agency, quotes $15,000 to $35,000 for standard third-party integrations and $50,000 or more for complex enterprise work. An automation tool costs a monthly plan if both apps have connectors. Write your brief first, and the quotes become comparable.
How long does an API integration take?
A simple connection between two apps with existing connectors can be live the same day in an automation tool. Imaginovation puts a focused custom API at four to eight weeks. The number of systems involved and the quality of each vendor's documentation move the timeline more than the code does.
How do I hire an API integration developer?
Write the brief first: the trigger and result in one sentence, the field map, the failure cases, the evidence you need, and what is out of scope. Then choose a route. On a marketplace you hire one developer and manage the build. With Pond you email the brief, agree the scope and the price on a call, and Pond builds it and hands it over with the test run.
Should I use Zapier or build a custom integration?
Use Zapier, Make or n8n when both apps have connectors, the logic is simple and the volume is modest. Build when a connector does not exist, when the logic has many conditions, when both systems edit the same record, or when per-task pricing costs more than a build. When only one step is missing, a hybrid works: the tool runs the flow and one small custom step does the rest.
What are examples of API integrations?
A deal won in a CRM creating a draft invoice in a billing tool. A paid order in Shopify creating a sales order in an ERP such as NetSuite. A form submission landing in a CRM and alerting a Slack channel. A payment provider's webhook updating a subscription record. A support ticket syncing to the product team's issue tracker.
What does a payment gateway integration involve?
More than the checkout. A reliable one handles webhooks that arrive late, twice or out of order, retries requests without charging twice, and records every event it acts on. Stripe documents each of these behaviours, which means each can be written into a brief as a test.
What is the difference between API integration and system integration?
An API integration connects two systems through their APIs so data moves between them, usually one flow with a defined trigger and result. System integration is the wider job of making many systems work as one, often including legacy software without modern APIs, and it usually involves middleware, data migration and a project team. A single API integration is a scoped build Pond can quote; a system integration program is agency work.