I'll speak to the Inca, as that's my area of expertise.

First of all, the Inca did not have a written language based on glyphs. Rather, they used a system of knotted cords known as quipu/ khipu to encode messages. While many quipu are obviously numerical, used for accounts of tribute owed and paid and different exchanges, census records etc. According to accounts given during the Colonial period, they also contained narrative information. However, while we can now identify numbers and the decimal system used on some quipu, it's still unclear how or to what extent additional narrative information will be eventually deciphered. Many early scholars even suggested that the quipu are more of a mnemonic device than a true recording of complete narrative information. One ongoing project is focused on finding examples of quipu to create a large comparative database in order to see whether common links can be created between them in order to identify matching pairs that record the same information. At some point we might find a specific quipu with Spanish documentary records that records the same information, but this requires finding both the quipu the documents in specific, associated context. While this would be an amazing Rosetta Stone moment, it hasn't happened yet.

Check this out for more info- https://khipukamayuq.fas.harvard.edu/

As a result, there are no currently intelligible records of the Inca that predate the arrival of Europeans. Nevertheless, there are a few documents authored by individuals of indigenous or mestizo (mixed) ancestry that have been used to shed light on Pre-Columbian lifeways.

The most famous is Felipe Guaman Poma de Ayala's Nueva Coronica y Buen Gobierno (new chronicle and good government). Essentially, it was a letter to the king of Spain requesting he put a stop to the abuses indigenous Andeans were suffering as a result of colonization. It's notable for it's strong and emotive language, illustrations, and labels in both Quechua (using the Spanish alphabet) and Spanish. Guaman Poma was the son of an indigenous noble, and it seems much of his work was an attempt to make the case that Andean and European concepts of nobility, just rule, and morality are compatible, and that embracing this compatibility was in the best interest of the Spanish crown.

The work of Inca Garcilaso de la Vega, the son of a Spanish conquistador and an indigenous noblewoman, is often held up as a different perspective on Inca history and culture. While Garcilaso was a mestizo by birth, he was educated in Spain at the age of 21 and lived there for the rest of his life. The European influences on his work is dramatically visible, and is a reason that some historians (erroneously in my opinion) argue that his accounts of Inca history are so biased as to be unreliable.

While Guaman Poma is often held up as the indigenous everyman to counter de la Vega's European educated biases, I think it's important to realize that both authors were members of a certain class. While their works are unique in providing an indigenous or mestizo perspective, that doesn't mean that they adequately reflect the beliefs or historical understandings of many indigenous Andean common people.

Sources:

Castro-Klarén, Sara. "WRITING SUBALTERITY: GUAMAN POMA AND GARCILASO, INCA." Dispositio 19, no. 46 (1994): 229-44. Accessed April 21, 2020. www.jstor.org/stable/41491515.

Guamán Poma de Ayala, Felipe, and Luis Bustíos Gálvez. La nueva crónica y buen gobierno. Lima: Editorial Cultura, Dirección de Cultura, Arqueología e Historia del Ministerio de Educación Pública del Perú, 1961.

Urton, Gary. "From Knots to Narratives: Reconstructing the Art of Historical Record Keeping in the Andes from Spanish Transcriptions of Inka Khipus." Ethnohistory 45, no. 3 (1998): 409-38. Accessed April 21, 2020. doi:10.2307/483319.

Vega, Garcilaso de la. The Royal Commentaries of Peru in Two Parts, the First Part Treating of the Original of Their Incas or Kings ..., the Second Part, Describing the Manner by Which That New World Was Conquered by the Spaniards ... England: Printed by Miles Flesher for Christopher Wilkinson ..., 1688.

As maybe you are aware the Spanish burned many pre-Hispanic codices but luck for is some few survive. For the Inca, while not explicitly texts from the Inca Empire, Guama Poma, a mestizo during the initial colonization period, graces us with "The First New Chronicle of Good Governing" that paints a picture of what the world was like before the Spanish and then after the Inca collapse. The Danes have digitized the original manuscript:

http://www5.kb.dk/permalink/2006/poma/info/en/frontpage.htm

As for the Aztec codices, it's complicated. Only a handful are pre-Colombian and need to be footnoted by anthropologists as they are heavy with symbolism and visual shorthand such as the Codex Borbonicus:

http://www.famsi.org/research/loubat/Borbonicus/thumbs0.html

Post-colonization there were many codices by comparison commissioned and made by Spanish monks working with indigenous artisans who together make elaborate works that meld together ideas and virtues from both continents. You can find all of them if you Wiki "Aztec Codex" but one famous one is the Codex Florentine:

https://tecpaocelotl.livejournal.com/25254.html

Hope that helped!