API · Create · Portfolios
Batch create portfolio entities.
Form a batch of new entities and add them all to a portfolio in one call. The single most common venture-studio operation — spinning up a cohort, staging a parallel-incorporation experiment, or migrating a back-of-the-napkin spreadsheet of subsidiaries into Matter.
Each item in the entities array is treated as an independent formation: it carves its own Intent, dispatches its own filings, and emits its own entity.state_changed events. The batch endpoint just guarantees portfolio membership lands together — partial successes are reported per-item rather than rolling back the batch.
Behavior - Per-entity events fire as each entity advances. The batch-level portfolio.batch_created event fires once the batch is fully resolved (every member either registered or rejected). - Entities that fail validation are returned in the response with error populated. They count against the batch but do not block siblings. - When the portfolio carries a shared_registered_agent_id, member entities default to that registered agent as the shared contract rolls out; per-entity overrides win where present. Until per-item registered-agent input ships on entity creation, set the registered agent on each entity after formation.
Returns 202 Accepted. On completion, emits one of: portfolio.entity_added, portfolio.batch_created. Subscribe via `POST /v1/webhook_endpoints` to consume. Idempotent via Idempotency-Key. See idempotency.
See also: Cookbook: build a portfolio dashboard, Portfolios API overview.
Errors: 400, 401, 404, 422, 429. The 404 not_found covers an unknown or out-of-org portfolio; 422 validation_failed covers a malformed envelope or an out-of-range batch size. See errors for the RFC 7807 envelope and per-code recovery guidance.
Last updated
Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
entitiesarray<object>RequiredResponse Body
application/json
application/problem+json
application/problem+json
application/problem+json
application/problem+json
application/problem+json
Request
curl -X POST "https://api.mattermode.com/v1/portfolios/{id}/entities/batch" \ -H "Content-Type: application/json" \ -d '{ "entities": [ {} ] }'const body = JSON.stringify({ "entities": [ {} ]})fetch("https://api.mattermode.com/v1/portfolios/{id}/entities/batch", { method: "POST", headers: { "Content-Type": "application/json" }, body})package mainimport ( "fmt" "net/http" "io/ioutil" "strings")func main() { url := "https://api.mattermode.com/v1/portfolios/{id}/entities/batch" body := strings.NewReader(`{ "entities": [ {} ] }`) req, _ := http.NewRequest("POST", url, body) req.Header.Add("Content-Type", "application/json") res, _ := http.DefaultClient.Do(req) defer res.Body.Close() body, _ := ioutil.ReadAll(res.Body) fmt.Println(res) fmt.Println(string(body))}import requestsheaders = { "Authorization": "Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc", "Matter-Version": "2026-06-10", "Idempotency-Key": "ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b",}payload = { "entities": [ {} ]}resp = requests.post( "https://api.mattermode.com/v1/portfolios/pf_S4dGqL2c/entities/batch", headers=headers, json=payload,)resp.raise_for_status()print(resp.json())import java.net.URI;import java.net.http.HttpClient;import java.net.http.HttpRequest;import java.net.http.HttpResponse;import java.net.http.HttpResponse.BodyHandlers;import java.time.Duration;import java.net.http.HttpRequest.BodyPublishers;var body = BodyPublishers.ofString("""{ "entities": [ {} ]}""");HttpClient client = HttpClient.newBuilder() .connectTimeout(Duration.ofSeconds(10)) .build();HttpRequest.Builder requestBuilder = HttpRequest.newBuilder() .uri(URI.create("https://api.mattermode.com/v1/portfolios/{id}/entities/batch")) .header("Content-Type", "application/json") .POST(body) .build();try { HttpResponse<String> response = client.send(requestBuilder.build(), BodyHandlers.ofString()); System.out.println("Status code: " + response.statusCode()); System.out.println("Response body: " + response.body());} catch (Exception e) { e.printStackTrace();}using System;using System.Net.Http;using System.Text;var body = new StringContent("""{ "entities": [ {} ]}""", Encoding.UTF8, "application/json");var client = new HttpClient();var response = await client.PostAsync("https://api.mattermode.com/v1/portfolios/{id}/entities/batch", body);var responseBody = await response.Content.ReadAsStringAsync();curl --request POST 'https://api.mattermode.com/v1/portfolios/pf_S4dGqL2c/entities/batch' \ --header 'Authorization: Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc' \ --header 'Matter-Version: 2026-06-10' \ --header 'Idempotency-Key: ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b' \ --header 'Content-Type: application/json' \ --data '{ "entities": [ {} ]}'const response = await fetch("https://api.mattermode.com/v1/portfolios/pf_S4dGqL2c/entities/batch", { method: "POST", headers: { "Authorization": "Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc", "Matter-Version": "2026-06-10", "Idempotency-Key": "ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b", "Content-Type": "application/json", }, body: JSON.stringify({ "entities": [ {} ] }),});if (!response.ok) { throw new Error(`Matter API ${response.status}: ${await response.text()}`);}const data = await response.json();console.log(data);Response
application/json{
"results": [
{}
]
}{
"type": "https://mattermode.com/docs/errors/invalid_request",
"title": "Invalid request",
"status": 400,
"code": "invalid_request",
"detail": "Request body could not be parsed as JSON.",
"doc_url": "https://mattermode.com/docs/guides/errors#invalid_request",
"request_id": "req_Qw9xYz8A"
}{
"type": "https://mattermode.com/docs/errors/authentication_required",
"title": "Authentication required",
"status": 401,
"code": "authentication_required",
"detail": "No bearer token was supplied. Pass `Authorization: Bearer sk_live_...` on every request.",
"doc_url": "https://mattermode.com/docs/guides/errors#authentication_required",
"request_id": "req_Qw9xYz8A"
}{
"type": "https://mattermode.com/docs/errors/not_found",
"title": "Not found",
"status": 404,
"code": "not_found",
"detail": "No entity with id `ent_Nq3KcAbc` is visible to this token.",
"doc_url": "https://mattermode.com/docs/guides/errors#not_found",
"request_id": "req_Qw9xYz8A"
}{
"type": "https://mattermode.com/docs/errors/validation_failed",
"title": "Validation failed",
"status": 422,
"code": "validation_failed",
"detail": "One or more fields failed validation. See `errors[]`.",
"doc_url": "https://mattermode.com/docs/guides/errors#validation_failed",
"request_id": "req_Qw9xYz8A",
"errors": [
{
"field": "founders[0].equity",
"code": "out_of_range",
"message": "Equity must sum to 100% across all founders."
}
]
}{
"type": "https://mattermode.com/docs/errors/rate_limit_exceeded",
"title": "Rate limit exceeded",
"status": 429,
"code": "rate_limit_exceeded",
"detail": "Request rate exceeded for this key. Retry after `retry_after` seconds or honor the `Retry-After` header.",
"doc_url": "https://mattermode.com/docs/guides/errors#rate_limit_exceeded",
"request_id": "req_Qw9xYz8A",
"retry_after": 30
}