POST

Workspace Management

Accept workspace invitation

/api/v2/workspace-invitations/acceptance

AUTHENTICATIONBearer token · workspaces:writeService owneridentity-service · identity-workspaceContract sourceOpenAPISTATUSProduction listed

Purpose and usage

What this endpoint does

Convert a valid workspace invitation into an active membership for the authenticated recipient.

When to use it

Call this after the signed-in user receives a one-time invitation token and chooses to join the named workspace.

OUTCOME · Join

What changes

Consumes the invitation and creates the invited role membership. It does not automatically select the workspace, create a wallet, or grant authority beyond that role.

WHY IT MATTERS

Requires both token possession and the intended authenticated account.
Creates a clear handoff from invitation state to role-bound membership.

ISOLATION + AUTHORITY

Acceptance is recipient-bound and workspace-bound. It cannot select another role, join another workspace, or confer wallet/MPC authority outside later policy ceremonies.

BEFORE YOU CALL

A bearer token with workspaces:write for an account whose verified email matches the invitation recipient.
The unexpired one-time token, a request signature, and an Idempotency-Key.

WHAT TO DO NEXT

Read the workspace and membership to confirm effective role.
Select it with PUT /api/v2/me/active-workspace when appropriate.

AGENT GUIDANCE

Show the workspace and invited role to the user before acceptance when that information is available from the invitation experience.
Do not accept a token under a different signed-in account or treat possession alone as sufficient identity proof.
After success, explicitly select the workspace only if the user wants to enter that context now.

Contract reference

Use the deployed OpenAPI for exact parameters, schemas and security requirements. The tables below provide integration guidance.

Open this operation in OpenAPI

Request and response

Make the request

Examples illustrate integration intent; the referenced OpenAPI operation and component schemas define the executable shape.

PARAMETERS

Headers, path, query, and body

NAMELOCATIONPRESENCETYPE / RULES / PURPOSE

AuthorizationheaderRequired

Bearer tokenCredential containing the workspaces:write scope.EXAMPLEBearer hc_live_…

Idempotency-KeyheaderRequired

ASCII string · 1–128Caller-generated key reused for every retry of the same logical mutation.EXAMPLElaunch-treasury-v1-001

Content-TypeheaderRequired

application/jsonSigned mutations accept canonical JSON only.EXAMPLEapplication/json

Content-DigestheaderRequired

RFC 9530 SHA-256 digestDigest of the exact transmitted body bytes.EXAMPLEsha-256=:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=:

Signature-InputheaderRequired

RFC 9421 signature parametersCovers @method, @path, content-digest, content-type, and idempotency-key; includes keyid, nonce, created, and expires.EXAMPLEsig1=("@method" "@path" "content-digest" "content-type" "idempotency-key");created=1786582800;expires=1786583100;nonce="01J…";keyid="machine-prod"

SignatureheaderRequired

Ed25519 HTTP Message SignatureSignature made by an active public key registered to the authenticated client.EXAMPLEsig1=:base64-signature:

tokenbodyRequired

one-time opaque invitation tokenToken delivered to the invited email address.

REQUEST

JSON body example

{
  "token": "hcwi_…"
}

STABLE ERROR CODES

Branch on the code, then follow the recovery action

These codes are published by the authoritative gateway contract for this endpoint. Treat message as safe diagnostic text; integrations should branch on code and HTTP status.

STATUSCODEMEANING

400invalid_jsonThe JSON body is malformed or fails the published identity schema.

400invalid_security_requestThe identity, workspace, permission, or key request is invalid.

400missing_idempotency_keyA nonempty Idempotency-Key is required for this mutation.

401invalid_credentialsThe bearer or proof-of-possession credential is invalid.

403step_up_requiredThe caller lacks role authority or fresh purpose-bound approval.

404workspace_resource_not_foundThe requested workspace, membership, or invitation was not found.

409security_conflictThe requested permission or identity transition conflicts with current state.

503identity_security_unavailableThe authoritative Identity security service is temporarily unavailable.

RESPONSES

Status and payload examples

200Invitation consumed and active membership returned.Mutation completed · JSON RESPONSE+

{
  "workspace_id": "b00dc220da8f480d86cdc11341372746",
  "tenant_uuid": "b00dc220da8f480d86cdc11341372746",
  "name": "Treasury Operations",
  "purpose": "TREASURY",
  "isolation_policy": "MPC",
  "status": "ACTIVE",
  "version": 1,
  "created_by": "d2f46f7e234c40a4a54e54208368d8d5",
  "created_at": "2026-08-12T21:00:00Z",
  "updated_at": "2026-08-12T21:00:00Z",
  "membership_id": "7bb755ad325c48e5a4f4cc7f5711fa62",
  "role": "ADMIN",
  "membership_version": 1,
  "idempotent_replay": false,
  "preference_version": null
}

INTEGRATION DECISION

CALLER ACTION: Accept the returned representation or receipt, then read the workspace and membership to confirm effective role.
RETRY SAFETY: Do not repeat a successful mutation merely to confirm it. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions.
STATE RECONCILIATION: Persist returned identifiers, versions, commitments, and receipts. Refresh the workspace, active roster, invitation, membership and preference versions, role, tenant binding, and idempotent mutation receipt.

400The JSON body or required signed headers are malformed.Request must change · JSON RESPONSE+

{
  "code": "invalid_json",
  "message": "The JSON body or required signed headers are malformed."
}

INTEGRATION DECISIONinvalid_json

CALLER ACTION: Rebuild the request from the live OpenAPI operation and correct the rejected method, media type, header, parameter, or body field.
RETRY SAFETY: Do not retry the same invalid request. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions.
STATE RECONCILIATION: Compare the submitted values with the documented constraints before another call. Refresh the workspace, active roster, invitation, membership and preference versions, role, tenant binding, and idempotent mutation receipt.
ESCALATE WHEN: Escalate when membership, invitation, role, optimistic version, tenant isolation, or last-administrator safety remains inconsistent.

401The bearer credential or HTTP Message Signature is missing, expired, replayed, or invalid.Authentication required · JSON RESPONSE+

{
  "code": "invalid_credentials",
  "message": "The bearer credential or HTTP Message Signature is missing, expired, replayed, or invalid."
}

INTEGRATION DECISIONinvalid_credentials

CALLER ACTION: Discard the rejected credential, complete the documented authentication or reassertion flow, and rebuild any request signature with fresh timestamps and nonces.
RETRY SAFETY: Retry only with a newly valid credential and fresh replay-protection values. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions.
STATE RECONCILIATION: Assume the outcome is unknown only when the connection failed after transmission; otherwise authentication failed before domain work. Refresh the workspace, active roster, invitation, membership and preference versions, role, tenant binding, and idempotent mutation receipt.
ESCALATE WHEN: Escalate when membership, invitation, role, optimistic version, tenant isolation, or last-administrator safety remains inconsistent.

403The principal lacks the required scope, workspace role, or tenant authority.Authority or policy denied · JSON RESPONSE+

{
  "code": "workspace_forbidden",
  "message": "The principal lacks the required scope, workspace role, or tenant authority."
}

INTEGRATION DECISIONworkspace_forbidden

CALLER ACTION: Verify the exact scope, tenant or workspace membership, owner boundary, step-up purpose, feature policy, and resource eligibility. Never broaden authority automatically.
RETRY SAFETY: Do not retry until the missing authority or policy condition has been deliberately resolved with least privilege.
STATE RECONCILIATION: Confirm the caller and resource resolve to the same authority boundary for tenant-bound workspaces, memberships, invitations, roles, preferences, revisions, and lifecycle receipts.
ESCALATE WHEN: Escalate when membership, invitation, role, optimistic version, tenant isolation, or last-administrator safety remains inconsistent.

404The workspace, invitation, or membership was not found in the caller's authority boundary.Resource not visible · JSON RESPONSE+

{
  "code": "workspace_not_found",
  "message": "The workspace, invitation, or membership was not found in the caller's authority boundary."
}

INTEGRATION DECISIONworkspace_not_found

CALLER ACTION: Verify the canonical identifier and authenticated owner boundary. A 404 may intentionally conceal a resource outside the caller's authority.
RETRY SAFETY: Do not retry the unchanged identifier repeatedly. Refresh the relevant collection or lookup before choosing another identifier.
STATE RECONCILIATION: Refresh the workspace, active roster, invitation, membership and preference versions, role, tenant binding, and idempotent mutation receipt.
ESCALATE WHEN: Escalate when membership, invitation, role, optimistic version, tenant isolation, or last-administrator safety remains inconsistent.

409The idempotency body, invitation state, or optimistic membership version conflicts with current state.State reconciliation required · JSON RESPONSE+

{
  "code": "workspace_conflict",
  "message": "The idempotency body, invitation state, or optimistic membership version conflicts with current state."
}

INTEGRATION DECISIONworkspace_conflict

CALLER ACTION: Stop the mutation sequence and fetch the latest authoritative resource, lifecycle state, version, ETag, reservation, or existing idempotency result.
RETRY SAFETY: Retry only after reconciling the conflict. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions.
STATE RECONCILIATION: Refresh the workspace, active roster, invitation, membership and preference versions, role, tenant binding, and idempotent mutation receipt.
ESCALATE WHEN: Escalate when membership, invitation, role, optimistic version, tenant isolation, or last-administrator safety remains inconsistent.

503The authoritative Identity workspace service is unavailable.Dependency unavailable or outcome uncertain · JSON RESPONSE+

{
  "code": "identity_security_unavailable",
  "message": "The authoritative Identity workspace service is unavailable."
}

INTEGRATION DECISIONidentity_security_unavailable

CALLER ACTION: Preserve the exact request and treat the outcome as uncertain until authoritative state proves whether it committed.
RETRY SAFETY: Reconcile before retrying. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions. Use bounded backoff with jitter.
STATE RECONCILIATION: Refresh the workspace, active roster, invitation, membership and preference versions, role, tenant binding, and idempotent mutation receipt.
ESCALATE WHEN: Escalate when membership, invitation, role, optimistic version, tenant isolation, or last-administrator safety remains inconsistent.

OPERATIONAL NOTES

Security and lifecycle guarantees

The authenticated account email must match the invitation recipient.
A byte-equivalent retry with the same Idempotency-Key returns the accepted membership; another token or body bound to that key returns 409.

UPGRADING FROM V1

Legacy calls replaced by this operation

If you maintain an older integration, use this map to find the V2 replacement. Do not translate the old request field-for-field: rebuild it from the V2 parameters and schemas above because identity, authorization, replay protection, and response semantics may have changed.

GET/api/v1/workspaces/accept/XXXXXXXWORKSPACE: Accept Workspace Invitation

Reference version and availability details

This route is implemented in canonical gateway source and appears in the production OpenAPI snapshot observed 2026-10-02T23:27:55.510Z. Authentication, tenant, feature, venue, and market policy still apply.

Verify the exact production OpenAPI operation Return to the V2 directory