Rishi: Yājñavalkya-tradition (Śukla-Yajurvedic school attribution; specific ṛṣi not explicitly marked in the input).
Devata: Agni (primary); Dyāvāpṛthivī (supporting invocation); Indra (invoked in relation to ājya-havis efficacy).
Chandas: Yajus (prose formula; not a fixed metrical ṛc).
Samhita Patha (Devanagari)अग्ने॒ वेर्हो॒त्रं वेर्दू॒त्यमव॑तां॒ त्वां द्यावा॑पृथि॒वी अव॒ त्वं द्यावा॑पृथि॒वी स्वि॑ष्ट॒कृद्दे॒वेभ्य इन्द्र॒ आज्ये॑न ह॒विषा॑ भू॒त्स्वाहा॒ सं ज्योति॑षा॒ ज्योति॑ः
Transliterationágnē vēr hótraṃ vēr dū́tyam ávatāṃ tvā́ṃ dyā́vā-pṛthivī́ áva tváṃ dyā́vā-pṛthivī́ sviṣṭa-kṛ́d devébhya índra ā́jyena havíṣā bhū́t svā́hā sáṃ jyótiṣā jyótiḥ
Translationਹੇ ਅਗਨੀ, ਨਿਸ਼ਚਯ ਹੀ ਤੇਰਾ ਹੋਤ੍ਰਿਤ੍ਵ (ਯਾਜਕ-ਪਦ) ਅਤੇ ਤੇਰਾ ਦੂਤ੍ਯ ਤੈਨੂੰ ਰੱਖਿਆ ਦੇਣ; ਦ੍ਯਾਵਾ-ਪ੍ਰਿਥਿਵੀ ਤੈਨੂੰ ਰੱਖਿਆ ਦੇਣ। ਹੇ ਦ੍ਯਾਵਾ-ਪ੍ਰਿਥਿਵੀ, ਅਤੇ ਹੇ ਸੁਵਿਸ਼੍ਟਕ੍ਰਿਤ (ਸੁਯਜ੍ਞ ਨੂੰ ਸੰਪੰਨ ਕਰਨ ਵਾਲੇ) ਅਗਨੀ—ਦੇਵਤਿਆਂ ਲਈ, ਹੇ ਇੰਦਰ, ਆਜ੍ਯ ਅਤੇ ਹਵਿਸ ਨਾਲ ਕਾਰਗਰ ਹੋ। ਸ੍ਵਾਹਾ! ਜੋਤ ਨਾਲ ਜੋਤ ਏਕ ਹੋਵੇ।
Padapatha (Word Analysis)अग्ने । वेः । होत्रम् । वेः । दूत्यम् । अवताम् । त्वाम् । द्यावापृथिवी इति । अव । त्वम् । द्यावापृथिवी इति । स्विष्टकृत् । देवेभ्यः । इन्द्र । आज्येन । हविषा । भूत् । स्वाहा । सम् । ज्योतिषा । ज्योतिः ।
Word by Wordवेर्indeed / verily (Vedic particle) होत्रम्the Hotṛ-function / priestly offering-service दूत्यम्the messenger-duty अवताम्may (they) protect / may (they) help द्यावापृथिवीHeaven-and-Earth अवdown; (as preverb) protect द्यावापृथिवीHeaven-and-Earth स्विष्टकृत्the well-accomplisher (who makes the offering well-performed) भूत्has become / may it become स्वाहाsvāhā (offering-call) 
Entities MentionedD
Dyāvāpṛthivī (Heaven and Earth) Viniyoga (Ritual Application)