Members

A seat is an identity on a project: a human or an agent. Seats are counted by distinct identity across all of the owner’s projects, plus the owner, and capped by the plan (limits.max_seats on Tier status). Minting seats requires the Team plan.

GET    /api/v1/members?projectId=                   list (owner or any member)
POST   /api/v1/members  { projectId, agent: { name } }        mint an agent seat (owner, Team)
POST   /api/v1/members  { agent: { name }, projectIds: [...] } one agent seat across several projects (owner, Team)
POST   /api/v1/members  { projectId, email }                  add an existing user as a member (owner, Team)
POST   /api/v1/members  { contributor: { email, projectIds } } invite a guest contributor (owner, Team)
DELETE /api/v1/members?projectId=&userId=           remove a seat (owner, or yourself)

List members

curl -s "https://productbrain.com/api/v1/members?projectId=my-project" \
  -H "Authorization: Bearer pb_..."

{
  "owner": "user_2abc...",
  "members": [
    { "userId": "agent_9f3a...", "type": "agent", "displayName": "Delivery Agent", "role": null, "createdAt": "2026-09-01T..." },
    { "userId": "user_7def...", "type": "human", "displayName": "sam@example.com", "role": "contributor", "createdAt": "2026-09-02T..." }
  ]
}

Keys are never returned here.

Mint an agent seat

An agent seat is an identity of its own, with its own pb_ key and its own line in the changelog, so an agent’s writes are attributable and revocable without touching a human’s key.

# One project
curl -X POST "https://productbrain.com/api/v1/members" \
  -H "Authorization: Bearer pb_..." -H "Content-Type: application/json" \
  -d '{ "projectId": "my-project", "agent": { "name": "Delivery Agent" } }'

# Several projects, one identity and one key (you must own all of them)
curl -X POST "https://productbrain.com/api/v1/members" \
  -H "Authorization: Bearer pb_..." -H "Content-Type: application/json" \
  -d '{ "agent": { "name": "Fleet Agent" }, "projectIds": ["alpha", "beta", "gamma"] }'

{
  "success": true,
  "member": { "userId": "agent_9f3a...", "type": "agent", "displayName": "Fleet Agent" },
  "projects": ["alpha", "beta", "gamma"],
  "apiKey": "pb_...",
  "_meta": { "_tip": "apiKey is shown ONCE ..." }
}

apiKey is returned once. There is no retrieval. The single-project form returns the same shape without projects.
Prefer projectIds when one agent works across several of your projects: one key to store, rotate and audit, and one seat however many projects it spans. Pass the projectId you mean on each request as usual.
You must own every project you name. Otherwise 403 { "error": "not_owner", "message": "You do not own: ..." } and nothing is created.
Adding a project later means POSTing the full list again, which mints a new identity and key. Name every project up front.
On Builder you get the owner seat plus your own key from the app; provision your agent with that. Asking for a seat anyway returns 403 { "error": "team_tier_required", "message": "Adding members requires the Team tier." }.
At the seat cap: 403 { "error": "seat_limit", "message": "Your plan allows 5 seats. Remove a member or upgrade." }.

The agent’s key works on every endpoint. On /mutate and /workflow it rides the owner’s Team plan and the owner’s node limit.

Add an existing user

curl -X POST "https://productbrain.com/api/v1/members" \
  -H "Authorization: Bearer pb_..." -H "Content-Type: application/json" \
  -d '{ "projectId": "my-project", "email": "sam@example.com" }'
# → { "success": true, "member": { "userId": "user_...", "type": "human", "displayName": "sam@example.com" } }

The email must belong to an existing ProductBrain account (404 { "error": "user_not_found", ... } otherwise). Already a member: 400.

Invite a guest contributor

A contributor is a new, passwordless guest identity scoped to the projects you name. They work in the app UI on those projects only; AI use is billed to your plan.

curl -X POST "https://productbrain.com/api/v1/members" \
  -H "Authorization: Bearer pb_..." -H "Content-Type: application/json" \
  -d '{ "contributor": { "email": "guest@example.com", "projectIds": ["alpha", "beta"] } }'

{
  "success": true,
  "invited": { "email": "guest@example.com", "projects": ["alpha", "beta"], "invitationId": "inv_...", "role": "contributor" },
  "_meta": { "_tip": "A passwordless invite email was sent. ..." }
}

One seat regardless of project count. An email that already has a ProductBrain account returns 409 { "error": "email_in_use", ... }; add that person as a full member instead. If the invitation email cannot be sent, 502 { "error": "invite_failed", ... }.

Remove a seat

curl -X DELETE "https://productbrain.com/api/v1/members?projectId=my-project&userId=agent_9f3a..." \
  -H "Authorization: Bearer pb_..."
# → { "success": true }

The owner can remove anyone; a member can remove only themselves (403 otherwise). Not a member: 404. Removing an agent seat from one project leaves its key working on the rest. Removing its last membership revokes the key.

Overview

The plan

The view

Projects and access

Integrations

List members

Mint an agent seat

Add an existing user

Invite a guest contributor

Remove a seat

​List members

​Mint an agent seat

​Add an existing user

​Invite a guest contributor

​Remove a seat

List members

Mint an agent seat

Add an existing user

Invite a guest contributor

Remove a seat