This is a dedicated wright.
Appearances aside, he's pretty spiffy, a construct created by busy magic item craftsmen to create more stuff.
The dedicated wright's supernatural ability item creation says
A dedicated wright can perform the daily tasks related to item creation on behalf of its master. The master must meet (or emulate) all the prerequisites to create the desired item normally, and pays the gold and XP cost himself. The only cost a dedicated wright can help with is time. The master spends 1 hour initiating the process, channeling spell prerequisites into the dedicated wright, and paying the XP cost to make the item. He may then leave, allowing the wright to carry the process through to completion. (Eberron Campaign Setting 285)
Emphaisis mine. Usually, when creating a magic item that has one or more spells as prerequisites, the creator or an assistant must provide that spell (as if the spell were cast except costing the caster no gp and no XP) each day of the magic item's construction. But what does that emphasized text in the supernatural ability item creation mean?
Possible Answers
The master channels the item's prerequisite spells into the the dedicated wright—no matter the item's cost or time to create—only once. Thereafter the dedicated wright is capable of completing that item's construction, but new spells must be channeled when another item is initiated.
Example A
Ana the Polite, a Wiz17 who employs no shenanigans and who is master of a dedicated wright, wants to use her feat Craft Wondrous Item to create for her djinni lover a censer of controlling air elementals (100,000 gp; 1 lb.) for his birthday.
Because she must make a pilgrimage to her mother's grave, she takes 1 hour initiating the creation process during which she channels the prerequisite spells summon monster VI and summon monster IX (presumably not casting the spells but treating the spells as if she had), pays 50,000 gp, and pays 4,000 XP.
In 100 days the dedicated wright will have completed the censer.
The master must channel spell prerequisites into the dedicated wright daily. If the master doesn't, the dedicated wright ceases construction. If the master lets an item lapse and initiates a new item for the dedicated wright to create, the time, money, and XP are wasted.
In addition, as above except the master can channel the prerequisite spells into the dedicated wright multiple times, gaining essentially 1 day's labor per set of prerequisite spells channeled into the dedicated wright for the purposes of constructing the item.
Example B
Ana the Polite, a Wiz17 who employs no shenanigans and who is master of a dedicated wright, wants to use her feat Craft Wondrous Item to create for her djinni lover a censer of controlling air elementals (100,000 gp; 1 lb.) for his birthday. Her Intelligence ability score of 33 limits her to 6 6th-level and 2 9th-level spells per day.
Because she must make a pilgrimage to her mother's grave, she takes 1 hour initiating the creation process during which she channels the prerequisite spells summon monster VI six times and summon monster IX twice (presumably not casting the spells but treating the spells as if she had), pays 50,000 gp, and pays 4,000 XP.
After 6 days the dedicated wright will need another summon monster VI and after 2 days the dedicated wright will another summon monster IX, but the dedicated wright will cease construction until it gets another summon monster IX. After 100 days of having both spells channeled and present simultaneously, the dedicated wright will have completed the censer.
Something else I haven't thought of.
The optimizer in me prefers number one, while the DM in me prefers the number two. The big difference between the two comes in meeting the prerequisites by expending further resources. For example, were Ana a druid therefore lacking summon monster spells on her spell list, she'd have to bring in outside assistance to get those spells channeled into her dedicated wright (if that's even possible). This need only be done once for each spell for number one, but need be done one hundred times for each spell for number two.
Official answers preferred but experienced opinions welcome.