API · Manage · Rounds
Create a round.
Open a priced-round envelope. The largest single legal event between formation and exit. NVCA-aligned: captures the term-sheet variables that drive the COI amendment, IRA / RRA / VA, SPA, side letters, board reconstitution, option-pool refresh, MFN crawl, blue-sky, and Form D.
Stages. term_sheet → drafting → signed → closed, with terminal cancelled. Use POST /rounds/{id}/advance to progress. Closing the round (POST /rounds/{id}/close) cascades the SAFE / note conversion math, the new share-class issuance to investors, and the post-close compliance filings.
Pre- vs post-money pool refresh is critical and undecidable from term sheet alone — set pre_money_pool_shuffle explicitly. true = the pool refresh comes out of pre-money (existing stockholders bear dilution; investor ownership target preserved); false = post-money (new investor bears dilution alongside existing stockholders). Default true matches NVCA model.
Last updated
Query Parameters
dry_runbooleanOptionalIf true, simulate the mutation and return the would-be resource, any cascaded
resources, and a fee estimate — without side effects. Available on every mutation.
Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
namestringRequiredInternal label (Series Seed, Series A, Series B-1, etc.).
kindstringRequiredOne of
"seed_priced""series_a""series_b""series_c""series_d""series_e_plus""bridge_priced""recap"pre_moneyobjectOptionalCurrency amount in the smallest unit (cents for USD).
amountintegerRequiredInteger in smallest unit. 100 = USD 1.00.
currencystringRequiredISO 4217 alpha-3, lower-cased.
investmentobjectOptionalCurrency amount in the smallest unit (cents for USD).
amountintegerRequiredInteger in smallest unit. 100 = USD 1.00.
currencystringRequiredISO 4217 alpha-3, lower-cased.
option_pool_refresh_basis_pointsintegerOptionalTarget post-close option-pool size in basis points of fully-diluted capitalization.
pre_money_pool_shufflebooleanOptionalWhether the option-pool refresh comes out of pre-money (existing stockholders bear dilution; investor ownership target preserved) or post-money. Defaults true (NVCA standard).
board_reconstitutionobjectOptionalinvestor_seatsintegerOptionalcommon_seatsintegerOptionalindependent_seatsintegerOptionalmfn_holdersarray<string>OptionalOutstanding instruments (typically SAFEs) with most-favored-nation rights that require retroactive repricing if this round's terms improve on theirs. Listed by ledger-entry ID.
closing_conditionsarray<object>OptionalkindstringOptionalOne of
"legal_opinion""ksl_payoff""key_employee_agreements""board_approval""stockholder_approval""regulatory_approval""qualified_financing_threshold""side_letter_execution""other"descriptionstringOptionaldue_datestring<date>OptionalsatisfiedbooleanOptionalmetadataobjectOptionalFlat 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}/rounds" \ -H "Content-Type: application/json" \ -d '{ "name": "Series A", "kind": "seed_priced", "pre_money": { "amount": 50000, "currency": "usd" }, "investment": { "amount": 50000, "currency": "usd" }, "option_pool_refresh_basis_points": 0, "pre_money_pool_shuffle": true, "share_class": { "name": "Series A Preferred", "liquidation_preference_multiple": 1, "participating": false, "participating_cap_multiple": 0, "dividend_rate": 0, "dividend_kind": "non_cumulative", "voting": "as_converted", "anti_dilution": "broad_based_wa", "pro_rata_rights": true, "drag_threshold_basis_points": 5001, "protective_provisions": [ "amend_coi" ] }, "board_reconstitution": { "investor_seats": 1, "common_seats": 2, "independent_seats": 0 }, "mfn_holders": [ "string" ], "closing_conditions": [ {} ], "metadata": {} }'const body = JSON.stringify({ "name": "Series A", "kind": "seed_priced", "pre_money": { "amount": 50000, "currency": "usd" }, "investment": { "amount": 50000, "currency": "usd" }, "option_pool_refresh_basis_points": 0, "pre_money_pool_shuffle": true, "share_class": { "name": "Series A Preferred", "liquidation_preference_multiple": 1, "participating": false, "participating_cap_multiple": 0, "dividend_rate": 0, "dividend_kind": "non_cumulative", "voting": "as_converted", "anti_dilution": "broad_based_wa", "pro_rata_rights": true, "drag_threshold_basis_points": 5001, "protective_provisions": [ "amend_coi" ] }, "board_reconstitution": { "investor_seats": 1, "common_seats": 2, "independent_seats": 0 }, "mfn_holders": [ "string" ], "closing_conditions": [ {} ], "metadata": {}})fetch("https://api.mattermode.com/v1/entities/{id}/rounds", { 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}/rounds" body := strings.NewReader(`{ "name": "Series A", "kind": "seed_priced", "pre_money": { "amount": 50000, "currency": "usd" }, "investment": { "amount": 50000, "currency": "usd" }, "option_pool_refresh_basis_points": 0, "pre_money_pool_shuffle": true, "share_class": { "name": "Series A Preferred", "liquidation_preference_multiple": 1, "participating": false, "participating_cap_multiple": 0, "dividend_rate": 0, "dividend_kind": "non_cumulative", "voting": "as_converted", "anti_dilution": "broad_based_wa", "pro_rata_rights": true, "drag_threshold_basis_points": 5001, "protective_provisions": [ "amend_coi" ] }, "board_reconstitution": { "investor_seats": 1, "common_seats": 2, "independent_seats": 0 }, "mfn_holders": [ "string" ], "closing_conditions": [ {} ], "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 = { "name": "Series A", "kind": "seed_priced", "pre_money": { "amount": 50000, "currency": "usd" }, "investment": { "amount": 50000, "currency": "usd" }, "option_pool_refresh_basis_points": 0, "pre_money_pool_shuffle": true, "share_class": { "name": "Series A Preferred", "liquidation_preference_multiple": 1, "participating": false, "participating_cap_multiple": 0, "dividend_rate": 0, "dividend_kind": "non_cumulative", "voting": "as_converted", "anti_dilution": "broad_based_wa", "pro_rata_rights": true, "drag_threshold_basis_points": 5001, "protective_provisions": [ "amend_coi" ] }, "board_reconstitution": { "investor_seats": 1, "common_seats": 2, "independent_seats": 0 }, "mfn_holders": [ "string" ], "closing_conditions": [ {} ], "metadata": {}}resp = requests.post( "https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/rounds", 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("""{ "name": "Series A", "kind": "seed_priced", "pre_money": { "amount": 50000, "currency": "usd" }, "investment": { "amount": 50000, "currency": "usd" }, "option_pool_refresh_basis_points": 0, "pre_money_pool_shuffle": true, "share_class": { "name": "Series A Preferred", "liquidation_preference_multiple": 1, "participating": false, "participating_cap_multiple": 0, "dividend_rate": 0, "dividend_kind": "non_cumulative", "voting": "as_converted", "anti_dilution": "broad_based_wa", "pro_rata_rights": true, "drag_threshold_basis_points": 5001, "protective_provisions": [ "amend_coi" ] }, "board_reconstitution": { "investor_seats": 1, "common_seats": 2, "independent_seats": 0 }, "mfn_holders": [ "string" ], "closing_conditions": [ {} ], "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}/rounds")) .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("""{ "name": "Series A", "kind": "seed_priced", "pre_money": { "amount": 50000, "currency": "usd" }, "investment": { "amount": 50000, "currency": "usd" }, "option_pool_refresh_basis_points": 0, "pre_money_pool_shuffle": true, "share_class": { "name": "Series A Preferred", "liquidation_preference_multiple": 1, "participating": false, "participating_cap_multiple": 0, "dividend_rate": 0, "dividend_kind": "non_cumulative", "voting": "as_converted", "anti_dilution": "broad_based_wa", "pro_rata_rights": true, "drag_threshold_basis_points": 5001, "protective_provisions": [ "amend_coi" ] }, "board_reconstitution": { "investor_seats": 1, "common_seats": 2, "independent_seats": 0 }, "mfn_holders": [ "string" ], "closing_conditions": [ {} ], "metadata": {}}""", Encoding.UTF8, "application/json");var client = new HttpClient();var response = await client.PostAsync("https://api.mattermode.com/v1/entities/{id}/rounds", body);var responseBody = await response.Content.ReadAsStringAsync();curl --request POST 'https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/rounds' \ --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 '{ "name": "Series A", "kind": "seed_priced", "pre_money": { "amount": 50000, "currency": "usd" }, "investment": { "amount": 50000, "currency": "usd" }, "option_pool_refresh_basis_points": 0, "pre_money_pool_shuffle": true, "share_class": { "name": "Series A Preferred", "liquidation_preference_multiple": 1, "participating": false, "participating_cap_multiple": 0, "dividend_rate": 0, "dividend_kind": "non_cumulative", "voting": "as_converted", "anti_dilution": "broad_based_wa", "pro_rata_rights": true, "drag_threshold_basis_points": 5001, "protective_provisions": [ "amend_coi" ] }, "board_reconstitution": { "investor_seats": 1, "common_seats": 2, "independent_seats": 0 }, "mfn_holders": [ "string" ], "closing_conditions": [ {} ], "metadata": {}}'const response = await fetch("https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/rounds", { 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({ "name": "Series A", "kind": "seed_priced", "pre_money": { "amount": 50000, "currency": "usd" }, "investment": { "amount": 50000, "currency": "usd" }, "option_pool_refresh_basis_points": 0, "pre_money_pool_shuffle": true, "share_class": { "name": "Series A Preferred", "liquidation_preference_multiple": 1, "participating": false, "participating_cap_multiple": 0, "dividend_rate": 0, "dividend_kind": "non_cumulative", "voting": "as_converted", "anti_dilution": "broad_based_wa", "pro_rata_rights": true, "drag_threshold_basis_points": 5001, "protective_provisions": [ "amend_coi" ] }, "board_reconstitution": { "investor_seats": 1, "common_seats": 2, "independent_seats": 0 }, "mfn_holders": [ "string" ], "closing_conditions": [ {} ], "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{
"resource": {
"id": "string",
"object": "round",
"entity_id": "ent_Nq3KcAbc",
"name": "Waypoint Systems, Inc.",
"kind": "seed_priced",
"stage": "term_sheet",
"created": 1745539200,
"updated": 1745539200,
"livemode": false
},
"intent": {
"id": "string",
"object": "intent",
"goal": "form_startup_ready_corporation",
"parameters": {},
"status": "draft",
"created": 1745539200,
"updated": 1745539200,
"livemode": false
},
"execution_plan": {
"steps": [
{
"operation": "string",
"status": "pending"
}
]
},
"authorization": {
"id": "string",
"object": "authorization",
"token_id": "tok_4Kj2m8pQ",
"action": "string",
"payload_hash": "string",
"status": "pending",
"expires_at": 1745539200,
"created": 1745539200,
"updated": 1745539200,
"livemode": false
},
"pending_filings": [
{
"id": "string",
"object": "filing",
"entity_id": "ent_Nq3KcAbc",
"type": "certificate_of_amendment",
"jurisdiction": "US-DE",
"status": "preparing",
"created": 1745539200,
"updated": 1745539200,
"livemode": false
}
],
"cascaded_documents": [
{
"id": "string",
"object": "document",
"entity_id": "ent_Nq3KcAbc",
"type": "certificate_of_incorporation",
"status": "draft",
"sha256": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
"version": 1,
"created": 1745539200,
"updated": 1745539200,
"livemode": false
}
],
"cascaded_resolutions": [
{
"id": "string",
"object": "resolution",
"entity_id": "ent_Nq3KcAbc",
"kind": "board_meeting",
"subject": "Approval of 2026 Equity Plan and initial pool of 2,000,000 shares",
"created": 1745539200,
"updated": 1745539200,
"livemode": false
}
],
"events_emitted": [
"string"
],
"applied_defaults": [
"string"
],
"next_steps": [
{
"endpoint": "POST /v1/entities/ent_Nq3KcAbc/tax_elections",
"reason": "Founder restricted-stock issuances require 83(b) within 30 days."
}
]
}{
"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/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
}