Mayor Marty Walsh today will unveil a first-of-its-kind public platform of performance metrics for city services, a bold move toward open data that marks the halfway point of his first term in office.

Fresh off a two-month testing period, the digital watchdog service known as CityScore lists the most telling data indicators from every facet of municipal government — including the city’s 311 app — and plainly states whether their performance is at, above or below targets.

From school attendance to the number of missed trash collections to stabbings and homicides to the rate of potholes being filled and graffiti being scrubbed, whether benchmarks are being met is there for all to see.

“Complete transparency,” is how Walsh described what the new platform represents for him. “And willingness to put out information even though it might not tell a good story every day. We’re willing to put it out there and let people know.”

Scores are derived by comparing current performance to either a goal set by the city or a three-year historical average. Anything over one means the city has surpassed targets, and anything below one means it’s falling short. A score of exactly one means the city is spot-on.

Conceived and developed by Walsh’s tech team, the back-end of the platform runs on Microsoft’s data management tool, SQL server. It feeds into business intelligence software that visually displays the data at boston.gov/CityScore, scheduled to go live at 11:30 a.m. today.

Designed with a green backdrop and white letters that hark back to the city’s famous Fenway Park scoreboard, CityScore boasts a pretty simple interface, with columns that list the performance of each category by the day, week and month.

Walsh is the first to admit he was initially hesitant to expose the live innards of city government on a 24/7 basis. When his chief of staff, Daniel Koh, first came to him with the idea, he said he wondered if CityScore might be a bit too transparent.

“I was concerned about having it live,” he said in an interview at his City Hall office, where CityScore is displayed on a 55-inch monitor. Walsh took about a week to consider the initial proposal and ultimately determined it was the right thing to do.

“We should be striving for excellence in customer service,” Walsh said. “That’s why we’re putting it out there. We shouldn’t be hiding it. If somebody wants to be critical of what we’re doing, that’s OK because we should be doing better.”

In areas where performance is falling short, the score will show up in red, and that’s when Walsh’s team starts digging deeper.

For the most part, the mayor says, department heads and employees like having the scores public because it shows how hard they work. And they’ve gotten used to having their own wall-mounted screens that feature CityScore and other digital charts.

The system is still being tweaked. Yesterday, for instance, the score for free public Wi-Fi users was out-of-whack.

Metrics are still being added, and the next step is to calculate the scores with realtime data as opposed to the 24-hour lag that currently exists.

CityScore may end up being more than just a tool for Boston, with federal records showing city officials have applied to trademark the name.

“No one has this. This is the first of its kind in the country — in the world,” Walsh said.

What a difference two years makes. It’s tough to imagine the late Mayor Thomas M. Menino peacefully coexisting with a veritable stock ticker of city performance. Yet much of the data used in calculating the scores was digitized under Menino. He didn’t personally embrace technology, but he knew its value. Walsh does both.

Chris Osgood, the mayor’s chief of streets, said the scores motivate staff, like the maintenance workers who were hitting their 48-hour targets and asked for it to be bumped to 24.

Said Osgood, “It’s a great example of how a department has said, ‘You know what, we’ve been hitting this 48-hour target and we can actually do better.’ ”

Erica Moura contributed to this report.