Rishi: Ṛgvedic attribution (Indra-stotra milieu; exact r̥ṣi depends on the underlying Ṛg source)
Devata: Indra (probable, by diction of ‘śacī’ and ‘sakhā’ in common usage)
Chandas: Tr̥ṣṭubh/Jagatī-class (source-dependent; requires confirmation from the underlying Ṛg hymn)
Samhita Patha (Devanagari)कया॑ नश्चि॒त्र आ भु॑वदू॒ती स॒दावृ॑ध॒: सखा॑ । कया॒ शचि॑ष्ठया वृ॒ता
Transliterationkáyā naś citrá ā́ bhuvad ūtī́ sadā́vṛdhaḥ sákhā | káyā śáciṣṭhayā vṛtā́ ||
TranslationDurch welches Mittel wird uns der wunderbare Freund, der ewig Wachsende, zur Hilfe kommen? Durch welche höchst wirksame Kraft soll er erwählt werden?
Padapatha (Word Analysis)कया । नः । चित्रः । आ । भुवत् । ऊती । सदा-वृधः । सखा । कया । शचिष्ठया । वृता ।
Word by Wordकयाby what? with which (means)? चित्रःbright; wondrous; excellent भुवत्may he become; may he be वृधःever-increasing; growing कयाby what? with which (means)? शचिष्ठयाby the most powerful/most skillful (power) 
Viniyoga (Ritual Application)