Resistance begins at home. For Silicon Valley, that means transforming an unprecedented protest movement against US President Donald Trump’s young presidency into something more than signs and slogans.

To do so, software engineers and executives in the Valley are writing a set of civic values they hope will become the minimum standard by which companies are judged as a place people want to work. “It’s not about workplace rights as much as what are some shared values related to government that we want our companies to endorse,” says Sam Altman, president of the Y Combinator seed fund, who sponsored a Tech Workers’ Values meeting to launch the process.

The April 9 meeting, held in a swank startup office in San Francisco’s SOMA district, was off-the-record, but the results are being shared as a Google document among attendees. When ready, it will be circulated in the larger tech community. Paralleling pledges such as Never.Again, Altman plans additional meetings to agree on shared values broad enough to unite software engineers—a disparate, libertarian-minded crew—and specific enough to extract real action from major technology companies.

The effort is crystallizing much larger political questions roiling the Valley: How to protect immigrants and the valuable talent they bring? What is the best way to offer fair pay and benefits to all employees? How can user privacy and data be protected from government intrusion? How can Silicon Valley prevent its technology from being used against citizens or in support of authoritarian regimes?

Once a text is agreed upon, organizers plan to enforce these values where employees wield the most power: at work. If enough companies and tech workers sign it, Altman is exploring a “workers’ council” for collective action or bargaining, avoiding a traditional union structure which has elicited fierce resistance among some in Silicon Valley’s individualist culture. He is also reaching out to Trump supporters so people of any political persuasion can get behind the final statement. But he’s prepared to fail. “If we go through this and there’s no consensus and sufficiently shared values, we don’t have to do anything,” says Altman.

The direction of tech workers’ political awakening is still up for grabs. It appears to be playing out on two levels: discrete, private meetings and strategy sessions out of the spotlight, and loud, visible outpourings of protest among workers and their employers. Silicon Valley executives, thus far, have been careful to stand with their employees. CEOs have outdone each other donating to the ACLU or attending airport protests after Trump’s travel ban from seven Muslim-majority countries.

Incredible scenes at Google headquarters today. Thousands came to #GooglersUnite protest on less than 1 day notice #NoBanNoWall #NoMuslimBan pic.twitter.com/pBaIWmluoD

— Tolu Thomas (@ToluThomas) January 31, 2017

Startups such as Fauna, Buoyant and Jelly Industries allow employees unlimited paid leave for political action, reports the Washington Post, and Facebook will give employees time off on May 1 to protest Trump’s immigration policies.

What all those efforts lack, however, is a clear statement of principles technology professionals widely agree are non-negotiable. “It’s such a young profession,” says Leigh Honeywell, a former security engineer at Slack and now a technology fellow at the ACLU. “We’re literally just inventing this field and putting thought into the ethics.”

Technologists increasingly see that their software has downsides. While it powers ever more of the global economy, it’s also enabling authoritarian states to conduct universal surveillance, racial profiling, deportations and political propaganda (see Facebook’s proposed censorship for China). Desire is growing for an accepted code of ethics to govern the technology profession the way the Hippocratic Oath guides doctors and medical professionals.

The non-profit Association for Computing Machinery, the largest scientific computing society, is now revising its own 1992 ethics code. Its preliminary changes (pdf) offer a glimpse of what’s to come. As written, the draft document, scheduled to be finalized in 2018, recasts software engineers’ role as protecting the public, similar to the oath taken by civil engineers. One major revision replaces the requirement that “one must always have appropriate approval” to access computer systems with one that professionals “should” do so except in the case of “an overriding concern for the public good.” In fact, the “public good” has been elevated to the “central concern during all professional computing work” and “an explicit criterion for quality” in technology.

Turning such ideals into policy, either at a company or in government, is a different matter. The Valley faces a White House hostile on many issues important to its employees. Elon Musk is the only remaining Silicon Valley executive on Trump’s advisory boards after the departure of Uber CEO Travis Kalanick. Silicon Valley’s sway over the White House may be at its lowest ebb in at least a decade.

In the midst of such partisanship, Altman wants the technology community to agree on common interests that transcend political parties. First, Silicon Valley needs to drop its reflexive opposition to Trump’s supporters and focus on values. Altman said he spent the last few months reaching out to 100 Trump voters in the middle of California and the Midwest to better understand their views. “We need to remember the other side is mostly made up of good people,” he said. “Misguided perhaps, or maybe with different values. But we’re trying to find what you have in common, and what you can build together.”