The earliest Old Testament canon is mentioned by Josephus circa 95CE, as well as the reason why they considered it "from God". From there, it's history is shown by Melito of Sardis circa 175CE. These earliest canons never included what came to be called the apocrypha.
Although he does not name specific books, it is quite clear to which 22 he refers. He also speaks of a valid prophetic line for their acceptance and not others. This, of course, is mentioned by Christ (Mat 11:13, Luke 16:16, Luke 24:44).
- “We have not, therefore, a multitude of books disagreeing and conflicting with one another; but we have only twenty-two, which contain the record of all time and are justly held to be divine.
- Of these, five are by Moses, and contain the laws and the tradition respecting the origin of man, and continue the history down to his own death. This period embraces nearly three thousand years.
- From the death of Moses to the death of Artaxerxes, who succeeded Xerxes as king of Persia, the prophets that followed Moses wrote the history of their own times in thirteen books. The other four books contain hymns to God, and precepts for the regulation of the life of men.
- From the time of Artaxerxes to our own day all the events have been recorded, but the accounts are not worthy of the same confidence that we repose in those which preceded them, because there has not been during this time an exact succession of prophets.
-Josephus, Against Apion-
He is very clear about which books they considered "God breathed", meaning the valid prophetic line.
For more context on Melito, "Melito may have been the immediate successor of the "angel" (or "apostle") of the church of Sardis, to whom our Great High Priest addressed one of the apocalyptic messages. He was an "Apostolic Father" in point of fact; he very probably knew the blessed Polycarp and his disciple Irenaeus. He is justly revered for the diligence with which he sought out the evidence which, in his day, established the Canon of the Old Testament, then just complete." see here.
As quoted by Eusebius; emphasis mine.
- Accordingly when I [Melito] went East and came to the place where these things were preached and done, I learned accurately the books of the Old Testament, and send them to thee as written below. Their names are as follows: Of Moses, five books: Genesis, Exodus, Numbers, Leviticus,1310 Deuteronomy; Jesus Nave, Judges, Ruth; of Kings, four books; of Chronicles, two; the Psalms of David,1311 the Proverbs of Solomon, Wisdom also,1312 Ecclesiastes, Song of Songs, Job; of Prophets, Isaiah, Jeremiah; of the twelve prophets, one book1313; Daniel, Ezekiel, Esdras.1314 From which also I have made the extracts, dividing them into six books.” Such are the words of Melito.
-Eusebius, Church History-
As quoted elsewhere.
I accordingly proceeded to the East, and went to the very spot where the things in question were preached and took place; and, having made myself accurately acquainted with the books of the Old Testament, I have set them down below, and herewith send you the list. Their names are as follows:—
The five books of Moses—Genesis, Exodus, Leviticus, Numbers, Deuteronomy; Joshua,3623 Judges, Ruth, the four books of Kings, the two of Chronicles, the book of the Psalms of David, the Proverbs of Solomon, also called the Book of Wisdom, Ecclesiastes, the Song of Songs, Job, the books of the prophets Isaiah, Jeremiah, of the twelve contained in a single book, Daniel, Ezekiel, Esdras. From these I have made my extracts, dividing them into six books.
-Book of Extracts-
This canon is the same as the Protestant canon, sans Esther. Some would argue, however, that Esther was also part of the one book "Esdras" (Ezra, Nehemia). Or it was a mere oversight as he mentions Esther elsewhere. See the links for more.
Jerome is an interesting figure in the history of the canon of Scripture. He wrote circa 400.
Preface to the Books of the Kings. Circa A.D. 391.
This preface, also known as the Prologus Galeatus, "Helmeted Preface," was written by Jerome about the year 391. In it he maintains that, for the Old Testament, only the Hebrew books traditionally regarded as Holy Scripture by the Jews are canonical, and the extra books of the Septuagint "are not in the canon."
This link will also provide more information on the canon. As noted in the comments, the definition of "early" is an interesting one. I try to find the earliest references and see what is said.
He wrote about 140 and taught in Rome. This is his confirmation of what Josephus and Melito had said about the prophetic line and authentic Scripture.
There were, then, among the Jews certain men who were prophets of God, through whom the prophetic Spirit published beforehand things that were to come to pass, ere ever they happened. ... And He was predicted before He appeared, first 5000 years before, and again 3000, then 2000, then 1000, and yet again 800; for in the succession of generations prophets after prophets arose.
First Apology, Chapter XXXI
So, which OT canon did the early church recognize? The answer is it recognized what the Protestants recognize for the same reason.