feat(auth-oauth2): custom parameters for authorization, token, and refresh requests (#629)

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

plugins/auth-oauth2/src/customParams.ts

@@ -0,0 +1,121 @@
+import type { JsonPrimitive } from "@yaakapp/api";
+
+export interface NameValue {
+  name: string;
+  value: string;
+}
+
+/** Custom entries for a single outgoing request */
+export interface CustomRequestParams {
+  headers: NameValue[];
+  body: NameValue[];
+}
+
+export interface CustomParams {
+  /** Query parameters appended to the authorization URL */
+  authorizationQuery: NameValue[];
+  token: CustomRequestParams;
+  /** Already merged over `token`, so the refresh request only reads this */
+  refresh: CustomRequestParams;
+}
+
+export const NO_CUSTOM_PARAMS: CustomParams = {
+  authorizationQuery: [],
+  token: { headers: [], body: [] },
+  refresh: { headers: [], body: [] },
+};
+
+/**
+ * A key_value form input stores its rows as a JSON-encoded array of pairs. The
+ * whole string goes through the template engine before it reaches the plugin,
+ * so a row's value can be a template.
+ */
+export function parsePairs(value: JsonPrimitive | undefined): NameValue[] {
+  if (value == null || value === "") return [];
+
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(String(value));
+  } catch {
+    console.log("[oauth2] Ignoring custom parameters that failed to parse");
+    return [];
+  }
+
+  if (!Array.isArray(parsed)) return [];
+
+  const pairs: NameValue[] = [];
+  for (const row of parsed) {
+    if (row == null || typeof row !== "object") continue;
+    const { name, value, enabled } = row as { name?: unknown; value?: unknown; enabled?: unknown };
+    if (enabled === false) continue;
+    const trimmedName = typeof name === "string" ? name.trim() : "";
+    if (trimmedName === "") continue;
+    pairs.push({ name: trimmedName, value: rowValue(value) });
+  }
+
+  return pairs;
+}
+
+/** The pair editor writes strings, but a hand-edited file may hold any primitive */
+function rowValue(value: unknown): string {
+  if (typeof value === "string") return value;
+  if (typeof value === "number" || typeof value === "boolean") return String(value);
+  return "";
+}
+
+/**
+ * Read every custom parameter list off the auth form.
+ *
+ * Token entries also apply to the refresh request, so the refresh lists are the
+ * token lists with the refresh-specific rows merged over them.
+ */
+export function readCustomParams(values: Record<string, JsonPrimitive | undefined>): CustomParams {
+  const tokenHeaders = parsePairs(values.tokenHeaders);
+  const tokenBody = parsePairs(values.tokenBodyParams);
+
+  return {
+    authorizationQuery: parsePairs(values.authorizationParams),
+    token: { headers: tokenHeaders, body: tokenBody },
+    refresh: {
+      headers: mergeHeaders(tokenHeaders, parsePairs(values.refreshHeaders)),
+      body: mergeFormParams(tokenBody, parsePairs(values.refreshBodyParams)),
+    },
+  };
+}
+
+/**
+ * Custom entries win over generated ones of the same name: every generated
+ * entry the custom list names is dropped, then the custom list is appended.
+ * Dropping by name rather than replacing in place means two custom rows sharing
+ * a name both survive, which repeatable headers and params rely on.
+ */
+function mergeByName<T extends NameValue>(
+  generated: T[],
+  custom: NameValue[],
+  { caseInsensitive }: { caseInsensitive: boolean },
+): (T | NameValue)[] {
+  if (custom.length === 0) return generated;
+
+  const normalize = (name: string) => (caseInsensitive ? name.toLowerCase() : name);
+  const overridden = new Set(custom.map((c) => normalize(c.name)));
+
+  return [...generated.filter((g) => !overridden.has(normalize(g.name))), ...custom];
+}
+
+export function mergeHeaders<T extends NameValue>(generated: T[], custom: NameValue[]) {
+  return mergeByName(generated, custom, { caseInsensitive: true });
+}
+
+export function mergeFormParams<T extends NameValue>(generated: T[], custom: NameValue[]) {
+  return mergeByName(generated, custom, { caseInsensitive: false });
+}
+
+/** Apply custom query parameters to an authorization URL, in place */
+export function applyQueryParams(url: URL, custom: NameValue[]) {
+  for (const name of new Set(custom.map((c) => c.name))) {
+    url.searchParams.delete(name);
+  }
+  for (const { name, value } of custom) {
+    url.searchParams.append(name, value);
+  }
+}

plugins/auth-oauth2/src/fetchAccessToken.ts

@@ -1,4 +1,6 @@
 import type { Context, HttpRequest, HttpUrlParameter } from "@yaakapp/api";
+import type { CustomRequestParams } from "./customParams";
+import { mergeFormParams, mergeHeaders } from "./customParams";
 import type { AccessTokenRawResponse } from "./store";
 
 export async function fetchAccessToken(
@@ -10,9 +12,10 @@ export async function fetchAccessToken(
     scope: string | null;
     audience: string | null;
     params: HttpUrlParameter[];
+    custom?: CustomRequestParams;
   } & ({ clientAssertion: string } | { clientSecret: string; credentialsInBody: boolean }),
 ): Promise<AccessTokenRawResponse> {
-  const { clientId, grantType, accessTokenUrl, scope, audience, params } = args;
+  const { clientId, grantType, accessTokenUrl, scope, audience, params, custom } = args;
   console.log("[oauth2] Getting access token", accessTokenUrl);
   const httpRequest: Partial<HttpRequest> = {
     method: "POST",
@@ -61,6 +64,12 @@ export async function fetchAccessToken(
     httpRequest.headers?.push({ name: "Authorization", value });
   }
 
+  // Merged last so custom entries override the credential headers and params above
+  if (custom) {
+    httpRequest.headers = mergeHeaders(httpRequest.headers ?? [], custom.headers);
+    httpRequest.body = { form: mergeFormParams(httpRequest.body?.form ?? [], custom.body) };
+  }
+
   httpRequest.authenticationType = "none"; // Don't inherit workspace auth
   const { httpResponse: resp, body: responseBody } = await ctx.httpRequest.send({ httpRequest });
 

plugins/auth-oauth2/src/getOrRefreshAccessToken.ts

@@ -1,4 +1,6 @@
 import type { Context, HttpRequest } from "@yaakapp/api";
+import type { CustomRequestParams } from "./customParams";
+import { mergeFormParams, mergeHeaders } from "./customParams";
 import type { AccessToken, AccessTokenRawResponse, TokenStoreArgs } from "./store";
 import { deleteToken, getToken, storeToken } from "./store";
 import { isTokenExpired } from "./util";
@@ -14,6 +16,7 @@ export async function getOrRefreshAccessToken(
     clientSecret,
     tokenName,
     forceRefresh,
+    custom,
   }: {
     scope: string | null;
     accessTokenUrl: string;
@@ -22,6 +25,7 @@ export async function getOrRefreshAccessToken(
     clientSecret: string;
     tokenName?: "access_token" | "id_token";
     forceRefresh?: boolean;
+    custom?: CustomRequestParams;
   },
 ): Promise<AccessToken | null> {
   const token = await getToken(ctx, tokenArgs);
@@ -69,6 +73,12 @@ export async function getOrRefreshAccessToken(
     httpRequest.headers?.push({ name: "Authorization", value });
   }
 
+  // Merged last so custom entries override the credential headers and params above
+  if (custom) {
+    httpRequest.headers = mergeHeaders(httpRequest.headers ?? [], custom.headers);
+    httpRequest.body = { form: mergeFormParams(httpRequest.body?.form ?? [], custom.body) };
+  }
+
   httpRequest.authenticationType = "none"; // Don't inherit workspace auth
   const { httpResponse: resp, body: responseBody } = await ctx.httpRequest.send({ httpRequest });
 

plugins/auth-oauth2/src/grants/authorizationCode.ts

@@ -1,6 +1,8 @@
 import { createHash, randomBytes } from "node:crypto";
 import type { Context } from "@yaakapp/api";
 import { getRedirectUrlViaExternalBrowser } from "../callbackServer";
+import type { CustomParams } from "../customParams";
+import { applyQueryParams, NO_CUSTOM_PARAMS } from "../customParams";
 import { fetchAccessToken } from "../fetchAccessToken";
 import { getOrRefreshAccessToken } from "../getOrRefreshAccessToken";
 import type { AccessToken, TokenStoreArgs } from "../store";
@@ -36,6 +38,7 @@ export async function getAuthorizationCode(
     pkce,
     tokenName,
     externalBrowser,
+    customParams = NO_CUSTOM_PARAMS,
   }: {
     authorizationUrl: string;
     accessTokenUrl: string;
@@ -52,6 +55,7 @@ export async function getAuthorizationCode(
     } | null;
     tokenName: "access_token" | "id_token";
     externalBrowser?: ExternalBrowserOptions;
+    customParams?: CustomParams;
   },
 ): Promise<AccessToken> {
   const tokenArgs: TokenStoreArgs = {
@@ -68,6 +72,7 @@ export async function getAuthorizationCode(
     clientSecret,
     credentialsInBody,
     tokenName,
+    custom: customParams.refresh,
   });
   if (token != null) {
     return token;
@@ -92,6 +97,10 @@ export async function getAuthorizationCode(
     authorizationUrl.searchParams.set("code_challenge_method", pkce.challengeMethod);
   }
 
+  // Applied before redirect_uri, which belongs to the callback flow rather than
+  // to the user: overriding it would send the code somewhere nothing listens
+  applyQueryParams(authorizationUrl, customParams.authorizationQuery);
+
   let code: string;
   let actualRedirectUri: string | null = redirectUri;
 
@@ -130,6 +139,7 @@ export async function getAuthorizationCode(
       ...(pkce ? [{ name: "code_verifier", value: pkce.codeVerifier }] : []),
       ...(actualRedirectUri ? [{ name: "redirect_uri", value: actualRedirectUri }] : []),
     ],
+    custom: customParams.token,
   });
 
   return storeToken(ctx, tokenArgs, response, tokenName);

plugins/auth-oauth2/src/grants/clientCredentials.ts

@@ -1,6 +1,8 @@
 import { createPrivateKey, randomUUID } from "node:crypto";
 import type { Context } from "@yaakapp/api";
 import jwt, { type Algorithm } from "jsonwebtoken";
+import type { CustomParams } from "../customParams";
+import { NO_CUSTOM_PARAMS } from "../customParams";
 import { fetchAccessToken } from "../fetchAccessToken";
 import type { TokenStoreArgs } from "../store";
 import { getToken, storeToken } from "../store";
@@ -109,6 +111,7 @@ export async function getClientCredentials(
     clientAssertionSecretBase64,
     clientCredentialsMethod,
     clientAssertionAlgorithm,
+    customParams = NO_CUSTOM_PARAMS,
   }: {
     accessTokenUrl: string;
     clientId: string;
@@ -120,6 +123,7 @@ export async function getClientCredentials(
     clientAssertionSecretBase64: boolean;
     clientCredentialsMethod: string;
     clientAssertionAlgorithm: string;
+    customParams?: CustomParams;
   },
 ) {
   const tokenArgs: TokenStoreArgs = {
@@ -143,6 +147,7 @@ export async function getClientCredentials(
     clientId,
     scope,
     params: [],
+    custom: customParams.token,
   };
 
   const fetchParams: Parameters<typeof fetchAccessToken>[1] =

plugins/auth-oauth2/src/grants/implicit.ts

@@ -1,5 +1,7 @@
 import type { Context } from "@yaakapp/api";
 import { getRedirectUrlViaExternalBrowser } from "../callbackServer";
+import type { CustomParams } from "../customParams";
+import { applyQueryParams, NO_CUSTOM_PARAMS } from "../customParams";
 import type { AccessToken, AccessTokenRawResponse } from "../store";
 import { getDataDirKey, getToken, storeToken } from "../store";
 import { isTokenExpired } from "../util";
@@ -18,6 +20,7 @@ export async function getImplicit(
     audience,
     tokenName,
     externalBrowser,
+    customParams = NO_CUSTOM_PARAMS,
   }: {
     authorizationUrl: string;
     responseType: string;
@@ -28,6 +31,7 @@ export async function getImplicit(
     audience: string | null;
     tokenName: "access_token" | "id_token";
     externalBrowser?: ExternalBrowserOptions;
+    customParams?: CustomParams;
   },
 ): Promise<AccessToken> {
   const tokenArgs = {
@@ -59,6 +63,10 @@ export async function getImplicit(
     );
   }
 
+  // Applied before redirect_uri, which belongs to the callback flow rather than
+  // to the user: overriding it would send the token somewhere nothing listens
+  applyQueryParams(authorizationUrl, customParams.authorizationQuery);
+
   let newToken: AccessToken;
 
   // Use external browser flow if enabled

plugins/auth-oauth2/src/grants/password.ts

@@ -1,4 +1,6 @@
 import type { Context } from "@yaakapp/api";
+import type { CustomParams } from "../customParams";
+import { NO_CUSTOM_PARAMS } from "../customParams";
 import { fetchAccessToken } from "../fetchAccessToken";
 import { getOrRefreshAccessToken } from "../getOrRefreshAccessToken";
 import type { AccessToken, TokenStoreArgs } from "../store";
@@ -16,6 +18,7 @@ export async function getPassword(
     credentialsInBody,
     audience,
     scope,
+    customParams = NO_CUSTOM_PARAMS,
   }: {
     accessTokenUrl: string;
     clientId: string;
@@ -25,6 +28,7 @@ export async function getPassword(
     scope: string | null;
     audience: string | null;
     credentialsInBody: boolean;
+    customParams?: CustomParams;
   },
 ): Promise<AccessToken> {
   const tokenArgs: TokenStoreArgs = {
@@ -40,6 +44,7 @@ export async function getPassword(
     clientId,
     clientSecret,
     credentialsInBody,
+    custom: customParams.refresh,
   });
   if (token != null) {
     return token;
@@ -57,6 +62,7 @@ export async function getPassword(
       { name: "username", value: username },
       { name: "password", value: password },
     ],
+    custom: customParams.token,
   });
 
   return storeToken(ctx, tokenArgs, response);

plugins/auth-oauth2/src/index.ts

@@ -11,6 +11,7 @@ import {
   DEFAULT_LOCALHOST_PORT,
   stopActiveServer,
 } from "./callbackServer";
+import { readCustomParams } from "./customParams";
 import {
   type CallbackType,
   DEFAULT_PKCE_METHOD,
@@ -468,6 +469,48 @@ export const plugin: PluginDefinition = {
                 values.clientCredentialsMethod === "client_assertion",
             }),
           },
+          {
+            type: "key_value",
+            name: "authorizationParams",
+            label: "Authorization Params",
+            description: "Query params appended to the authorization URL.",
+            optional: true,
+            dynamic: hiddenIfNot(["authorization_code", "implicit"]),
+          },
+          {
+            type: "key_value",
+            name: "tokenHeaders",
+            label: "Token Headers",
+            description:
+              "Headers sent with the token request, and when refreshing unless overridden.",
+            optional: true,
+            dynamic: hiddenIfNot(["authorization_code", "password", "client_credentials"]),
+          },
+          {
+            type: "key_value",
+            name: "tokenBodyParams",
+            label: "Token Body Params",
+            description:
+              "Form params sent with the token request, and when refreshing unless overridden.",
+            optional: true,
+            dynamic: hiddenIfNot(["authorization_code", "password", "client_credentials"]),
+          },
+          {
+            type: "key_value",
+            name: "refreshHeaders",
+            label: "Refresh Headers",
+            description: "Headers sent only when refreshing the token.",
+            optional: true,
+            dynamic: hiddenIfNot(["authorization_code", "password"]),
+          },
+          {
+            type: "key_value",
+            name: "refreshBodyParams",
+            label: "Refresh Body Params",
+            description: "Form params sent only when refreshing the token.",
+            optional: true,
+            dynamic: hiddenIfNot(["authorization_code", "password"]),
+          },
         ],
       },
       {
@@ -506,6 +549,7 @@ export const plugin: PluginDefinition = {
       const headerPrefix = stringArg(values, "headerPrefix");
       const grantType = stringArg(values, "grantType") as GrantType;
       const credentialsInBody = values.credentials === "body";
+      const customParams = readCustomParams(values);
       const tokenName = values.tokenName === "id_token" ? "id_token" : "access_token";
 
       // Build external browser options if enabled
@@ -546,6 +590,7 @@ export const plugin: PluginDefinition = {
             : null,
           tokenName: tokenName,
           externalBrowser: externalBrowserOptions,
+          customParams,
         });
       } else if (grantType === "implicit") {
         const authorizationUrl = stringArg(values, "authorizationUrl");
@@ -561,6 +606,7 @@ export const plugin: PluginDefinition = {
           state: stringArgOrNull(values, "state"),
           tokenName: tokenName,
           externalBrowser: externalBrowserOptions,
+          customParams,
         });
       } else if (grantType === "client_credentials") {
         const accessTokenUrl = stringArg(values, "accessTokenUrl");
@@ -577,6 +623,7 @@ export const plugin: PluginDefinition = {
           scope: stringArgOrNull(values, "scope"),
           audience: stringArgOrNull(values, "audience"),
           credentialsInBody,
+          customParams,
         });
       } else if (grantType === "password") {
         const accessTokenUrl = stringArg(values, "accessTokenUrl");
@@ -591,6 +638,7 @@ export const plugin: PluginDefinition = {
           scope: stringArgOrNull(values, "scope"),
           audience: stringArgOrNull(values, "audience"),
           credentialsInBody,
+          customParams,
         });
       } else {
         throw new Error(`Invalid grant type ${String(grantType)}`);