API · Create · Entities
Update the entity.
Updates the mutable fields on an entity — metadata, mailing address, aliases. Changes to immutable fields (legal name, principal address) require a Certificate-of-Amendment filing via POST /entities/{id}/filings with type: certificate_of_amendment.
Last updated
Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
aliasesarray<string>Optionalmailing_addressobjectOptionalStructured address.
line1stringRequiredline2stringOptionalcitystringRequiredcountystringOptionalCounty, parish, or borough. Optional for most addresses but required
in the registered-agent block of certain state filings (DE Certificate
of Incorporation per 8 Del. C. §131; analogous fields in NY and MD,
parishes in LA). When omitted, the recommendation engine derives the
county from line1 + region against the @repo/jurisdictions data
— populated automatically for Matter-provided registered agents.
regionstringRequiredState, province, or region code (e.g. DE, CA, NY).
postal_codestringRequiredcountrystringRequiredISO 3166-1 alpha-2.
metadataobjectOptionalFlat string-to-string map. Up to 50 keys. Keys: max 40 chars, charset
[A-Za-z0-9_\\-.]. Values: max 500 chars. Keys prefixed matter_ are reserved
for platform use. Metadata is retrievable but not filterable via query params.
Response Body
application/json
application/problem+json
application/problem+json
application/problem+json
application/problem+json
Request
curl -X POST "https://api.mattermode.com/v1/entities/{id}" \ -H "Content-Type: application/json" \ -d '{ "aliases": [ "string" ], "mailing_address": { "line1": "548 Market St", "city": "San Francisco", "region": "CA", "postal_code": "94104", "country": "US" }, "metadata": {} }'const body = JSON.stringify({ "aliases": [ "string" ], "mailing_address": { "line1": "548 Market St", "city": "San Francisco", "region": "CA", "postal_code": "94104", "country": "US" }, "metadata": {}})fetch("https://api.mattermode.com/v1/entities/{id}", { method: "POST", headers: { "Content-Type": "application/json" }, body})package mainimport ( "fmt" "net/http" "io/ioutil" "strings")func main() { url := "https://api.mattermode.com/v1/entities/{id}" body := strings.NewReader(`{ "aliases": [ "string" ], "mailing_address": { "line1": "548 Market St", "city": "San Francisco", "region": "CA", "postal_code": "94104", "country": "US" }, "metadata": {} }`) 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 = { "aliases": [ "string" ], "mailing_address": { "line1": "548 Market St", "city": "San Francisco", "region": "CA", "postal_code": "94104", "country": "US" }, "metadata": {}}resp = requests.post( "https://api.mattermode.com/v1/entities/ent_Nq3KcAbc", 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("""{ "aliases": [ "string" ], "mailing_address": { "line1": "548 Market St", "city": "San Francisco", "region": "CA", "postal_code": "94104", "country": "US" }, "metadata": {}}""");HttpClient client = HttpClient.newBuilder() .connectTimeout(Duration.ofSeconds(10)) .build();HttpRequest.Builder requestBuilder = HttpRequest.newBuilder() .uri(URI.create("https://api.mattermode.com/v1/entities/{id}")) .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("""{ "aliases": [ "string" ], "mailing_address": { "line1": "548 Market St", "city": "San Francisco", "region": "CA", "postal_code": "94104", "country": "US" }, "metadata": {}}""", Encoding.UTF8, "application/json");var client = new HttpClient();var response = await client.PostAsync("https://api.mattermode.com/v1/entities/{id}", body);var responseBody = await response.Content.ReadAsStringAsync();curl --request POST 'https://api.mattermode.com/v1/entities/ent_Nq3KcAbc' \ --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 '{ "aliases": [ "string" ], "mailing_address": { "line1": "548 Market St", "city": "San Francisco", "region": "CA", "postal_code": "94104", "country": "US" }, "metadata": {}}'const response = await fetch("https://api.mattermode.com/v1/entities/ent_Nq3KcAbc", { 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({ "aliases": [ "string" ], "mailing_address": { "line1": "548 Market St", "city": "San Francisco", "region": "CA", "postal_code": "94104", "country": "US" }, "metadata": {} }),});if (!response.ok) { throw new Error(`Matter API ${response.status}: ${await response.text()}`);}const data = await response.json();console.log(data);Response
application/json{
"id": "ent_Nq3KcAbc",
"object": "entity",
"status": "draft",
"type": "c_corp",
"jurisdiction": "US-DE",
"legal_name": "Waypoint Systems, Inc.",
"aliases": [
"string"
],
"formed_at": 0,
"dissolved_at": 0,
"acquired_at": 0,
"merged_at": 0,
"sold_at": 0,
"corporate_transaction_id": "ctx_9hNm2Bxy",
"principal_address": {
"line1": "548 Market St",
"city": "San Francisco",
"region": "CA",
"postal_code": "94104",
"country": "US"
},
"mailing_address": {
"line1": "548 Market St",
"city": "San Francisco",
"region": "CA",
"postal_code": "94104",
"country": "US"
},
"registered_agent_id": "ra_FbWcEoP9",
"tax_profile_id": "tax_ZqVbXrLn",
"stakeholder_ids": [
"string"
],
"cap_table_id": "string",
"equity_plan_ids": [
"string"
],
"qualifications": [
{
"id": "string",
"object": "qualification",
"entity_id": "ent_Nq3KcAbc",
"status": "qualifying",
"created": 0,
"updated": 0,
"livemode": false
}
],
"compliance": {},
"intent_id": "int_3sR8wPbX",
"incorporator_receipt_id": "rcp_8sQp4LbR",
"portfolio_id": "pf_studio_fund_i",
"metadata": {},
"created": 1745539200,
"updated": 1745539200,
"livemode": false
}{
"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/invalid_state_transition",
"title": "Invalid state transition",
"status": 409,
"code": "invalid_state_transition",
"detail": "Entity ent_Nq3KcAbc is in state `dissolved`; `dissolve` is not a valid transition.",
"doc_url": "https://mattermode.com/docs/guides/errors#invalid_state_transition",
"request_id": "req_Qw9xYz8A",
"current_state": "dissolved",
"attempted_transition": "dissolve",
"allowed_transitions": []
}{
"type": "https://mattermode.com/docs/errors/dissolution_prerequisites_missing",
"title": "Dissolution prerequisites missing",
"status": 409,
"code": "dissolution_prerequisites_missing",
"detail": "Voluntary dissolution requires `board_resolution_id` and `stockholder_consent_id`, or `auto_generate_resolutions: true`.",
"doc_url": "https://mattermode.com/docs/guides/errors#dissolution_prerequisites_missing",
"request_id": "req_Qw9xYz8A"
}{
"type": "https://mattermode.com/docs/errors/valuation_stale",
"title": "409A valuation stale",
"status": 409,
"code": "valuation_stale",
"detail": "Active 409A val_AbCd1234 is older than 12 months or superseded by a material event. Issuing ISOs at the prior strike risks IRC §409A violation. Refresh via POST /entities/{id}/valuations/{id}/refresh_request.",
"doc_url": "https://mattermode.com/docs/guides/errors#valuation_stale",
"request_id": "req_Qw9xYz8A"
}{
"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
}