Attio API review
Best API-first CRM
POST /v2/objects/companies/records Authorization: Bearer $ATTIO_TOKEN # reads 100 requests per second # writes 25 requests per second # 429 carries Retry-After as a date, not seconds
Attio is the CRM in this directory that was designed around its API rather than having one bolted on afterwards. The Attio CRM API reaches objects, attributes and lists that you define yourself, and the developer platform ships that API alongside an app SDK, an MCP server and a SQL interface as one thing rather than four.
Nothing about the Attio API is metered. Calls cost nothing, the free plan includes API access, and what you actually pay for is seats and credits: $44 per user a month on Plus, $99 on Pro, or nothing at all on Free. Credits are consumed by enrichment and AI features inside the product, not by your own API calls.
The constraint, and the number worth designing around, is throughput. Attio publishes one rate limit for the whole API: 100 requests a second for reads and 25 a second for writes. That write figure is the one that shapes a bulk load.
One consequence of nothing being metered is worth drawing out, because it changes how you should build. When calls are free, the cheap pattern is to read often and cache little, which is the opposite of what you do against a credit-metered provider. The thing you are rationing here is requests per second rather than money, so the design question is concurrency rather than frugality.
The rest of the category is in the CRM and sync APIs listing.
Attio API pricing, plan by plan
Attio API pricing is really seat pricing. Four tiers, each adding credits per seat and capabilities rather than API access, because every tier already has that.
Free
- Full REST API access
- 100 seat credits a month
- 250 workspace credits a month
Plus
- 500 seat credits a month
- 1,500 workspace credits a month
- Billed monthly or annually
Pro
- 1,000 seat credits a month
- 10,000 workspace credits a month
- The tier Attio marks as popular
Enterprise
- 2,500 seat credits a month
- Custom workspace credits
Workspace credits can be topped up at $85 a month for an extra 5,000, or $70 a month on an annual commitment. Annual billing takes roughly 20% off every seat price. The free plan is a real plan rather than a trial, and because API access is on it, you can build and test an integration end to end before anyone is billed.
This trips people up when they compare Attio to the enrichment providers here. An Attio credit is spent by enrichment and AI features inside the product, not by a REST call. Reading ten thousand records costs zero credits and zero dollars; it costs you throughput. If your integration only reads and writes your own data, the credit column on the pricing page is irrelevant to you and seats are the entire bill.
One limit for the whole API, and writes are the tight one
Attio API rate limits are refreshingly simple: 100 requests a second for reads and 25 a second for writes, applied across the whole API rather than per endpoint. Attio notes it may reduce the limit during incident response, and may permanently lower it for specific data-heavy endpoints, in which case the endpoint documents its own figure.
| Operation | Limit | What it means in practice |
|---|---|---|
| Reads | 100/s | A 100,000-record sync reads in under 17 minutes. |
| Writes | 25/s | The same 100,000 records write in about 67 minutes. This is your bottleneck. |
| Exceeded | 429 | Always a 429, always with a Retry-After header. |
| Per endpoint | Usually none | Data-heavy endpoints may be lower, and say so on their own page. |
Retry-After is a date, not a number
This is the detail that breaks a generic client.
- Attio sends Retry-After: Tue, 23 May 2023 14:42:01 GMT, an HTTP-date.
- Most libraries expect an integer number of seconds and will mis-parse it.
- The reset is usually the following clock second, so the correct wait is short.
- The JSON body carries type: rate_limit_error and code: rate_limit_exceeded.
A 429 is safe to retry
Attio states that a rate-limited request was not processed.
- Nothing partially applied, so there is no dedupe problem on retry.
- Sleep until the reset, or push the request onto a background queue.
- Design for 429 even if you never expect the volume, because the limit can drop during an incident.
- Security issues, including a leaked token, go to security@attio.com.
One number for reads and one for writes, across the whole API, is the simplest ceiling any CRM in this directory publishes, and the simplicity is the feature. There is no per-endpoint accounting to learn and no daily pool that a colleague's marketplace app can quietly drain. Size a job with one division and move on.
How to create an Attio API key
Attio supports two authentication styles and the right one depends on whether the integration is yours or something you distribute. For your own workspace, an access token sent as a bearer is the whole job. For an app other workspaces install, OAuth 2.0 is the route, and the developer console at build.attio.com is where apps are created.
Access token
The route for an internal integration or a pipeline.
- Sent as Authorization: Bearer <token>.
- Scoped to the workspace that issued it.
- The Attio API key most people mean when they search for one.
OAuth 2.0
For an app installed in workspaces you do not own.
- Apps are built and configured in the developer console at build.attio.com.
- A leaked client secret or access token should be reported to security@attio.com.
- The app SDK is a separate surface from the REST API and has its own docs.
Pick by who the integration is for rather than by which is quicker. An access token is right for your own scripts against your own workspace; OAuth is right the moment somebody else's workspace is involved, and retrofitting it later means reissuing every credential you handed out.
Where the Attio API documentation lives
Attio publishes more developer surface than any other CRM here, and splits it by what you are building rather than by object. The Attio API documentation and the Attio API reference are the same site, at developers.attio.com, which also serves as docs.attio.com, so whatever you call it, the Attio API docs you are searching for land on one place.
| Surface | Where | What it answers |
|---|---|---|
| Overview | developers.attio.com/docs/overview | Where to start, and which surface fits your build. |
| REST API | developers.attio.com/rest-api/overview | Objects, lists, records and attributes over HTTP. |
| Rate limiting | docs.attio.com/rest-api/guides/rate-limiting | The 100 and 25 per second figures, and how to handle a 429. |
| App SDK | developers.attio.com/sdk/overview | Building an app that runs inside Attio rather than calling it. |
| MCP | developers.attio.com/mcp/overview | The Attio MCP server, for agents. |
| SQL | developers.attio.com/sql/overview | Query your workspace with SQL rather than REST. |
| llms.txt | docs.attio.com/llms.txt | The full page index as Markdown, for an agent or for finding a page fast. |
The SQL interface is the one worth knowing about and the one nobody expects from a CRM. For reporting and for one-off questions about your own data it beats paginating a REST endpoint, and it does not count against the write limit at all. Append .md to any docs URL for the Markdown version, which is also how an agent should read this site.
Attio also ships an MCP server, and it is on the MCP page with the others in this directory.
Attio's own walkthrough of the API
Attio publishes this on its own channel, so it is Attio's account of Attio, not ours. It is here because a rate card cannot show you the thing moving, and a minute or two of the product is faster than any paragraph on this page at telling you whether the shape of it fits yours.
YouTube · Attio Build with Attio | How to vibe code a Luma Integration with the Attio App SDK 1:34 · Published December 2025A speed run rather than a tutorial: somebody builds a working Luma integration against the Attio App SDK with Cursor and one prompt. Watch it for what the developer platform exposes, not for how long an integration takes, because a demo is built against a case the builder picked.
Published 11 December 2025 on Attio, the channel Attio's own pages link to, and read on 13 October 2026. Nothing in it is a source for a price or a limit on this page: every figure in the tables above comes from an Attio page.
Strengths and limits
Attio is the API-first CRM in this directory, and the trade for that is breadth of ecosystem.
What it does well
- Full REST API on the free plan, so you can build and test before anyone is billed.
- You define the objects and attributes, so the schema matches your motion rather than a vendor's idea of a deal.
- Four developer surfaces that ship together: REST, app SDK, MCP and SQL.
- One published rate limit for the whole API, which makes capacity planning a single calculation.
- A 429 is documented as unprocessed, so retries are safe and need no idempotency dance.
Where it falls short
- 25 writes a second is the real ceiling, and a large backfill is measured in hours.
- Retry-After is an HTTP-date rather than seconds, which most clients mis-parse.
- Priced per user, so a team of ten on Pro is $990 a month before anyone calls the API.
- A smaller integration ecosystem than HubSpot or Salesforce, so more of the connecting is yours to build.
- Rate limits can be lowered during an incident, so the published figure is a ceiling rather than a guarantee.
The pattern is that Attio is strong where the data model is the problem and weak where throughput or breadth is. Nothing on the left-hand column helps a team whose complaint is the bill, and nothing on the right matters much to a team whose pipeline genuinely does not fit contacts and deals.
Where Attio data comes from, and what you may do with it
The question that arrives late and expensively is not how good the data is, it is who is allowed to hold it. These are the fields each one returns, the coverage it claims and the compliance it publishes.
| Provider | Fields returned | Coverage | Compliance | Redistribution |
|---|---|---|---|---|
| Attio API | CRM records, Work email, Firmographics | Global | GDPR DPA SOC 2 Type II | Not stated |
None of these states a redistribution position on its pricing or docs pages. Internally that never matters. Put the rows in something your customers can see and it becomes the question your legal team asks first.
Two practical notes that apply to every provider on this page. A compliance badge describes the vendor, not your use of it, so a GDPR DPA does not give you a lawful basis for the outreach you send. And every one of these vendors runs its own opt-out, which means a person who asks you to delete their record has to be removed from your copy as well as from theirs.
If Attio is not the answer
Four providers in the CRM and sync APIs listing that solve the same problem differently. Each one is a trade, and the trade is named.
HubSpot
Free tierThe opinionated alternative with a free tier that also includes full API access, plus marketing and ticketing in the same account.
Pipedrive
US$14/seat/moUS$14 a seat with API access on every plan and a pipeline that works out of the box. The cheapest way to stop paying for flexibility.
Salesforce
US$125/seat/moThe other CRM here with genuinely first-class custom objects, plus the Metadata API to deploy schema changes properly.
Clay
$167/moNot a CRM. Named because teams drawn to Attio are often really after a flexible table for research work, and that is a different product.
The full set, organized by the reason people leave, is on the Attio alternatives page.
Attio against the obvious rival
Same rate cards, read side by side, with the arithmetic done on a worked volume rather than left to you: HubSpot vs Attio, Attio vs Salesforce, Attio vs Pipedrive and Attio vs Clay.
The same again, against the rest of the field: Apollo vs Attio, Attio vs folk, Attio vs Twenty and Attio vs Close.
Every pairing in the directory is on the compare hub.
HubSpot vs Attio
CompareA free CRM API against a CRM whose data model you define in code.
Attio vs Salesforce
CompareDefine the schema in code for free, or buy the deepest API in the category by the seat.
Attio vs Pipedrive
CompareA schema you define in code against a pipeline that works out of the box.
Before you build against it
Four things to settle first, each one read off Attio's own pages. The ticks are remembered in this browser, so you can come back to a half-finished integration.
Who should actually buy this
Buy Attio when the CRM is something your team builds on rather than something it logs into. If your GTM motion has objects that are not contacts, companies and deals, and if an engineer is going to keep them in sync with something else, this is the CRM in this directory designed for that job.
The free plan makes the evaluation honest. Full API access, your own schema, no card: build the integration you are worried about and find out whether the write limit is a problem before you have bought a single seat.
Do not buy it to save money on a large team. At $44 to $99 per user a month, Attio is not cheap next to HubSpot's free tier, and the reason to choose it is the data model and the developer platform rather than the price. If nobody on your team is going to write code against it, you are paying for the half of the product you will not use.
Where it genuinely wins is the migration you have not had yet. A CRM whose objects are declared in code is one you can reshape when the business changes, and the cost of that flexibility is paid once rather than every time somebody adds a custom field to work around the model. If your last CRM project was a six-month exercise in bending a contact into something it was not, that is the thing worth paying $44 a seat for.
One last thing to check before committing a team to it. Attio is a CRM and a developer platform and nothing else, so sending, sequencing and the data itself are all separate contracts. Price the whole stack rather than the seat, because an Attio-centered setup is usually three vendors and the comparison that matters is against the total, not against another CRM's line item.
Attio is one of the providers in the agent-driven account research stack on this site, where the cost is worked out end to end at $0.09 a record.
A CRM you can shape is a CRM you have to shape.
Attio will model your motion exactly, which means someone has to decide what the model is. Frontal designs the objects, the sync and the routing with your team, builds it inside your workspace, and leaves you owning it.
Worked with 300+ companies. A senior operator runs your account.
Nothing worth quoting yet
The harvest this site runs searches Reddit for Attio threads where the API itself is the subject, and it has not come back with a quote that survives the transcription rules yet. When one does, it lands here. Nothing on this page leans on an unquoted paraphrase.
Attio API, answered
Is the Attio API free?
Free plan with full API access, 100 seat credits a month. Paid use starts at $44/user/mo.
How much does the Attio API cost?
Attio starts at $44/user/mo. Billing is per seat, subscription and free tier. Read from Attio's own pricing page on 8 October 2026.
What are the Attio API rate limits?
100 requests/s for reads, 25/s for writes, across the whole API.
How do I get an Attio API key?
Bearer token or OAuth 2.0. The current steps are in Attio's own documentation, which is authoritative on anything that has changed since 8 October 2026.
Does Attio have an MCP server?
Yes. Part of the Attio developer platform. It is listed with the others on the MCP page.