API · Manage · Equity
Amend the convertible.
Amend the economic terms of an outstanding SAFE or convertible note. The canonical use case is the MFN cascade: when a new SAFE is issued with terms more favourable than an outstanding MFN-clause SAFE, this endpoint generates the amendment side letter that upgrades the original SAFE to the new terms.
?dry_run=true returns the proposed amendment side letter without generating it — call before live execution to surface the diff in a review UI.
On live call, the platform generates a side-letter Document of type=side_letter linked via attaches_to to the original SAFE document, opens a SigningEnvelope for the original investor, and on signature appends to ShareLedgerEntry.mfn_amendments[] with the triggering peer entry id.
Errors with 409 not_eligible_for_mfn if the convertible has no MFN clause, with 409 mfn_window_expired if the window has elapsed, and with 409 already_amended_for_peer if the same triggering entry has already produced an amendment.
Last updated
Path Parameters
idstringRequiredconvertible_idstringRequiredShareLedgerEntry id of the SAFE/note grant being amended.
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.
amendment_reasonstringRequired"mfn_triggered""mutual_modification""error_correction"triggered_by_entry_idstringOptionalRequired when amendment_reason=mfn_triggered.
new_termsobjectOptionalPatch over the existing SAFE terms.
valuation_cap_centsintegerOptionaldiscount_ratenumberOptionalsafe_variantstringOptionalResponse Body
application/json
application/json
application/problem+json
application/problem+json
Request
curl -X POST "https://api.mattermode.com/v1/entities/string/convertibles/string/amend" \ -H "Content-Type: application/json" \ -d '{ "amendment_reason": "mfn_triggered" }'const body = JSON.stringify({ "amendment_reason": "mfn_triggered"})fetch("https://api.mattermode.com/v1/entities/string/convertibles/string/amend", { 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/string/convertibles/string/amend" body := strings.NewReader(`{ "amendment_reason": "mfn_triggered" }`) 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 = { "amendment_reason": "mfn_triggered"}resp = requests.post( "https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/convertibles/led_M8sNxK2f/amend", 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("""{ "amendment_reason": "mfn_triggered"}""");HttpClient client = HttpClient.newBuilder() .connectTimeout(Duration.ofSeconds(10)) .build();HttpRequest.Builder requestBuilder = HttpRequest.newBuilder() .uri(URI.create("https://api.mattermode.com/v1/entities/string/convertibles/string/amend")) .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("""{ "amendment_reason": "mfn_triggered"}""", Encoding.UTF8, "application/json");var client = new HttpClient();var response = await client.PostAsync("https://api.mattermode.com/v1/entities/string/convertibles/string/amend", body);var responseBody = await response.Content.ReadAsStringAsync();curl --request POST 'https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/convertibles/led_M8sNxK2f/amend' \ --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 '{ "amendment_reason": "mfn_triggered"}'const response = await fetch("https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/convertibles/led_M8sNxK2f/amend", { 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({ "amendment_reason": "mfn_triggered" }),});if (!response.ok) { throw new Error(`Matter API ${response.status}: ${await response.text()}`);}const data = await response.json();console.log(data);Response
application/json{
"proposed_terms_diff": {
"clauses": [
{
"clause_kind": "valuation_cap",
"before": null,
"after": null,
"more_favorable": true,
"ratchet_into_safe": true,
"scope_match": true,
"rationale": "string"
}
]
},
"proposed_clause_text": "string"
}{
"amendment_document_id": "string",
"envelope_id": "string",
"proposed_terms_diff": {
"clauses": [
{
"clause_kind": "valuation_cap",
"before": null,
"after": null,
"more_favorable": true,
"ratchet_into_safe": true,
"scope_match": true,
"rationale": "string"
}
]
}
}{
"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/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"
}