Which Unified API Solutions Have a Usage-Based Pricing Model?
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As of October 2026, Unified.to is the only unified API in this comparison with a published usage-based price: it meters API calls. Ampersand also bills by usage, per action, but publishes no rates, and several agent tool platforms meter calls too: Composio and Merge Agent Handler bill tool calls, StackOne bills credits per tool or API call, and Arcade bills tool calls plus authorization events. Nango is a hybrid that charges per connection plus compute hours and data transfer, and the other unified APIs price by connection, customer, connector or contract. For B2B SaaS teams with free tiers, many low-activity customers or AI agents whose activity varies, the difference decides whether an idle customer costs you anything.
What counts as usage-based pricing?
Usage-based pricing is pricing set by the number of API requests (or tool calls) you make, independent of how many customers, connected accounts or integrations you have. Under that definition:
- You can support unlimited customers and connections
- Cost follows API activity
- An idle customer adds no cost
- The rate per unit is published, so you can model cost before you sign
Most vendors, Unified.to included, also sell enterprise contracts. What decides the model is what the published price is anchored to.
What doesn't count as usage-based pricing?
A plan can include an API allowance and still not be usage-based: if the price is anchored to customers, connections, connectors or a contract, it fails the definition. That rules out:
- Per-connection pricing: billing per linked account, whatever its activity
- Per-customer or per-consumer pricing: billing per end customer using integrations
- Per-connector pricing: billing per integration you enable
- Capped tiers: plans that cap API calls and move you to the next tier when you exceed the cap
- Contract pricing: prices set in an order form, where usage isn't the billing unit
Which unified API vendors use usage-based pricing?
Of the 16 vendors below, five meter usage at published rates (Unified.to, Composio, StackOne, Arcade and Merge Agent Handler), Ampersand meters usage without publishing rates, Nango combines a connection fee with compute and transfer meters, and the other nine price by connection, customer, connector or contract (as of October 2026). Only one of the five, Unified.to, sells a maintained unified API with shared data models per category; the other four are agent tool platforms, and StackOne's unified APIs are Legacy and no longer in active development.
| Vendor | Type | What it bills on | Does usage set the price? | Published entry price |
|---|---|---|---|---|
| Unified.to | Unified API | API calls | Yes | Grow from $750 a month for 750,000 calls, then $1.00 per 1,000; unlimited customers and connections (12 Oct 2026) |
| Composio | Agent tool platform | Tool calls | Yes | Hobby free for 100,000 tool calls a month; Pro $29 a month including $29 of credit, then $0.0003 per tool call (12 Oct 2026) |
| StackOne | Agent tool platform | Credits (1 tool or API call = 1 credit) | Yes | OEM Core free; OEM Enterprise priced by annual credit commit, rates unpublished; Gateway Team $600 a month (12 Oct 2026) |
| Arcade | Agent tool platform | Tool calls and authorization events | Yes | Free for 2,000 tool calls and 2,000 auth events a month; Team $25 a month plus $0.01 per tool call and $0.10 per auth event (8 Oct 2026) |
| Merge Agent Handler | Agent tool platform | Tool-call credits (1 call = 1 credit) | Yes | Free for 2,000 credits a month; Pro $1,000 a month for 25,000 credits (8 Oct 2026) |
| Ampersand | Integration platform | Actions (reads, writes, events delivered) | Yes | Not published; custom plans set included actions (12 Oct 2026) |
| Nango | Integration platform | Connections, compute hours, data transfer | Partly | Free for 10 connections; Pay-as-you-go $50 monthly minimum (returned as credits), $0.29 per connection a month, $0.72 per compute hour, $0.50 per GB (8 Oct 2026) |
| Merge | Unified API | Production Linked Accounts | No | First 3 free; Launch $650 a month for up to 10, then $65 per account (8 Oct 2026) |
| Finch | Unified API | Connections | No | Starter $65 per connection a month, up to 15 connections, read-only, for employers under 500 employees (8 Oct 2026) |
| Apideck | Unified API | Active consumers | No | Launch $599 a month for 25 consumers in one category (8 Oct 2026) |
| Paragon | Embedded iPaaS | Connected Users | No | Not published (8 Oct 2026) |
| Truto | Unified API | Connectors enabled | No | Expansion from $999 per connector a year, 10-connector minimum (8 Oct 2026) |
| Knit | Unified API | Plan fee plus connected accounts | No | Start Up $499 a month, connected accounts priced by contract (8 Oct 2026) |
| Kombo | Unified API | Annual platform fee plus connected customers | No | Not published (8 Oct 2026) |
| Codat | Unified API | Annual platform fee plus active companies | No | Not published (8 Oct 2026) |
| Rutter | Unified API | Billable connections | No | Not published (8 Oct 2026) |
| A tool call on an agent tool platform isn't the same unit as a unified API call, so the rates aren't directly comparable; on Composio, for example, each tool uses its provider's own input and output schema. Several entry prices above sit below Grow's $750 because they cap the plan in other ways: Apideck Launch covers one category, Merge Launch syncs daily, Finch Starter is read-only and syncs every 24 hours, and Knit Start Up syncs every 24 hours (as of 8 October 2026). Grow includes every category and every integration, with change events on supported integrations. For what each pricing model costs at 100, 1,000 and 10,000 customers, and which is easiest to forecast, see usage-based vs per-connection pricing. |
How do you tell whether a pricing page is really usage-based?
Put five questions to the pricing page; a usage-based price passes all five.
- Does an idle customer cost anything? Under usage-based pricing, a customer who connects and then makes no calls adds nothing to the bill.
- Does a second integration for the same customer change the price? It shouldn't. If it does, the billing unit is the connection.
- Are empty checks or failed calls billed? Change detection on systems without webhooks polls the source. Ask whether a check that finds nothing, or a call that fails, counts as billable: Nango bills compute for every sync run, even one that finds no changes, and Merge Agent Handler counts failed and rule-blocked tool calls toward its credits (8 October 2026).
- Is there a published overage rate? If there's an allowance, the rate above it should be on the page. "Unlimited" can still carry a limit: Apideck's pricing FAQ says paid plans include unlimited API calls, while its help centre says requests return a 402 error once the account reaches its limit (30 September 2026), and Truto's unlimited API calls sit under a fair usage policy with no published threshold (8 October 2026).
- Is the billing unit something you control? API requests are; connected accounts, consumers and contract terms are set by your customer count or your contract.
Unified.to's answers, as of 12 October 2026: idle customers and extra integrations add nothing; checks that find nothing, failed deliveries and retriable read errors aren't billed; successful API calls are billed, with each webhook page delivered counting as one call; and the overage rate is published per plan and falls as you move up, from $1.00 per 1,000 calls on Grow to $0.75 on Pro and $0.50 on Scale.
What does usage-based pricing cost per customer?
At 100 customers making about 11 API requests a day each, the bill on Unified.to is $750 a month on Grow, about $7.50 per customer (our calculation, as of 12 October 2026).
- Volume: 100 customers × 1 connected account × 11 requests a day × 31 days = 34,100 requests a month.
- What the $7.50 is: 34,100 calls is under 5% of Grow's 750,000 included calls, so $7.50 is Grow's monthly minimum spread across 100 customers, not a per-call cost. At the same activity, Grow's included calls cover about 2,200 customers before overage.
- Above the allowance: each extra 1,000 calls costs $1.00 on Grow, $0.75 on Pro or $0.50 on Scale.
- What isn't charged: no per-customer, per-connection or per-integration fees on any plan. Grow and Pro start with a 30-day free trial.
Your own call volume sets the real figure: count resources synced × records per customer × pages per sync × syncs a month, plus webhook pages delivered.
Start your free 30-day trial or book a demo to model your own call volume on Unified.to.
Written by Mallory Greene.
About the author: Mallory Greene is Head of Marketing at Unified.to. She writes about integration infrastructure, unified APIs, and MCP for technical teams. Based in Toronto.