Function oAuthLinearCallback

apps/hash-api/src/integrations/linear/oauth.ts:127–281

(req, res)

  never,
  { code: string; state?: string }
> = async (req, res) => {
  const { code, state } = req.query;

  if (!req.context.vaultClient) {
    res.status(501).send({ error: "Vault integration is not configured." });
    return;
  }

  if (!state) {
    res.status(400).send({ error: "No state provided" });
    return;
  }

  const stateData = stateMap.get(state);

  if (!stateData) {
    res.status(400).send({ error: "Invalid state" });
    return;
  }

  if (stateData.actorEntityId !== req.user?.entity.metadata.recordId.entityId) {
    res.status(403).send({ error: "State mismatch" });
    return;
  }

  const now = new Date();
  if (stateData.expires < now) {
    res.status(400).send({ error: "State expired" });
    return;
  }

  const { actorEntityId } = stateData;

  stateMap.delete(state);

  if (!linearClientId || !linearClientSecret) {
    res.status(501).send({ error: "Linear integration is not configured." });
    return;
  }

  const formData = new URLSearchParams();
  formData.append("client_id", linearClientId);
  formData.append("client_secret", linearClientSecret);
  formData.append("code", code);
  formData.append("redirect_uri", linearOAuthCallbackUrl);
  formData.append("grant_type", "authorization_code");

  const response = await fetch("https://api.linear.app/oauth/token", {
    method: "POST",
    body: formData.toString(),
    headers: {
      "content-type": "application/x-www-form-urlencoded",
    },
  }).then(
    (resp) =>
      resp.json() as Promise<{ access_token: string; expires_in: number }>,
  );