How to Add Team Seats to Claude API Access

The short answer

Anthropic's own API console doesn't have a native "seats" concept — it gives you one organization with API keys you create and manage manually. If you want each team member to have their own scoped access, their own usage visibility, and a single invoice instead of five people sharing one secret key in a Slack message, you need a layer on top of the raw Claude API that handles multi-user key management for you.

That's the practical path most teams end up on: either build a thin internal proxy that issues per-user keys against one shared Anthropic account, or use a service that already does this. Below is how to do both, and what to watch for with each approach.

Why "just share the API key" breaks down

A single Anthropic API key works fine for one developer. It stops working once more than one person touches it:

• No per-person usage attribution. You can't tell whose script burned through the monthly budget.
• No individual revocation. If someone leaves the team, you have to rotate the key for everyone, not just them.
• No spend caps per person. One runaway script can consume the whole team's budget with no warning.
• Awkward billing. Anthropic bills the account, not the seat — there's no built-in per-user invoice line.
• Security sprawl. Shared secrets in .env files, Slack DMs, and shared vaults are a classic audit failure waiting to happen.

If your team is two people prototyping, this might be tolerable for a while. If you're onboarding engineers, giving contractors scoped access, or need to show a finance team where the spend is going, you need actual seat-level separation.

Option 1: Build it yourself

You can build a minimal multi-tenant layer yourself:

1. Keep one master Anthropic API key, stored server-side only.
2. Build a small proxy service that authenticates each team member (JWT, session, whatever you already use).
3. On each request, the proxy forwards to Anthropic using the master key, but logs the request against the authenticated user's ID.
4. Add your own rate limiting and budget tracking per user ID in a database.
5. Expose revocation by disabling the user's proxy account, not the shared key.

This works, but it's real engineering effort: you're now maintaining an auth system, a usage ledger, rate limiting, and a proxy that has to stay compatible with Anthropic's API surface (including streaming and tool use) as it evolves. For a two-person side project this is overkill. For a team shipping a product on Claude, it's a legitimate but ongoing maintenance cost.

Option 2: Use a service built for this

This is exactly the gap SubToAPI fills. It sits between your team and your existing Claude access and turns it into a proper multi-seat HTTPS API:

• Each team member gets their own sub_live_... application API key, scoped to them.
• Seats are managed from one dashboard — add a developer, remove a developer, no key rotation ceremony for the whole team.
• Usage metadata (tokens, requests) is tracked per key, so you can see exactly who's using what.
• Streaming and tool use work the same as calling Claude directly, so you don't rewrite your integration.
• One invoice per month, not one Anthropic bill you have to manually split across departments.

Adding a seat in practice

Once you're on a Team (€19/seat) or Scale (€49/seat) plan, adding a seat looks like this:

1. Go to your dashboard and invite the teammate by email.
2. They accept the invite and get issued their own sub_live_... key.
3. They drop that key into their environment the same way they would an Anthropic key:

export SUBTOAPI_KEY="sub_live_xxx"

1. They call the API exactly as documented:

curl https://api.subtoapi.app/v1/messages \
  -H "Authorization: Bearer $SUBTOAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4",
    "max_tokens": 1024,
    "messages": [
      { "role": "user", "content": "Summarize this ticket thread." }
    ]
  }'

1. You see their usage show up in the dashboard immediately, broken out from everyone else's.

No shared secrets, no manual rotation when someone leaves — you just remove their seat. Pricing is per-seat (Solo €9 for a single user, Team €19/seat, Scale €49/seat for larger orgs with heavier usage), and there's a free trial at /signup if you want to test it with your actual team before committing.

What this doesn't change

Seats control access and attribution, not the underlying model behavior. Each team member still calls the same Messages API shape, gets the same streaming support, and can use tools the same way — see /docs/messages, /docs/streaming, and /docs/tools for the request formats. Adding seats is purely an access-management layer on top of that.

Choosing between DIY and a managed layer

| Factor | Build it yourself | Managed seats | |---|---|---| | Setup time | Days to weeks | Minutes | | Ongoing maintenance | You own it | Handled for you | | Per-user revocation | You build it | Built in | | Usage visibility per seat | You build it | Built in | | Billing | Manual splitting | Per-seat invoice |

If your team is under five people and you have the engineering time to spare, DIY is viable. If you'd rather spend that time on your product, a managed layer like SubToAPI gets you there faster — check /pricing for the full seat breakdown, or start with /docs/quickstart to see how fast the integration goes.

Getting started

1. Decide if you need per-seat attribution now or can delay it.
2. If now: sign up, invite your team, issue keys, done — no proxy to maintain.
3. If building it yourself: budget for auth, logging, and rate limiting as ongoing work, not a one-time task.

Questions

Does Anthropic offer native team seats? No. Anthropic's console gives you organization-level API keys you manage manually. There's no built-in per-user seat, usage split, or revocation system — that's handled by you or a third-party layer.

Will adding seats change how I call the Claude API? No. With SubToAPI, each seat gets its own key but calls the same Messages API shape, with the same streaming and tool use support documented at /docs/messages and /docs/streaming.

What happens when a team member leaves? Remove their seat from the dashboard and their key stops working immediately. No need to rotate a shared key for the entire team.