Anthropic's Claude Code can now read your Slack messages and write code for you

Anthropic on Monday launched a beta integration that connects its fast-growing Claude Code programming agent directly to Slack, allowing software engineers to delegate coding tasks without leaving the workplace messaging platform where much of their daily communication already happens.

The release, which Anthropic describes as a "research preview," is the AI safety company's latest move to embed its technology deeper into enterprise workflows — and comes as Claude Code has emerged as a surprise revenue engine, generating over $1 billion in annualized revenue just six months after its public debut in May.

"The critical context around engineering work often lives in Slack, including bug reports, feature requests, and engineering discussion," the company wrote in its announcement blog post. "When a bug report appears or a teammate needs a code fix, you can now tag Claude in Slack to automatically spin up a Claude Code session using the surrounding context."

From bug report to pull request: how the new Slack integration actually works

The mechanics are deceptively simple but address a persistent friction point in software development: the gap between where problems get discussed and where they get fixed.

When a user mentions @Claude in a Slack channel or thread, Claude analyzes the message to determine whether it constitutes a coding task. If it does, the system automatically creates a new Claude Code session. Users can also explicitly instruct Claude to treat requests as coding tasks.

Claude gathers context from recent channel and thread messages in Slack to feed into the Claude Code session. It will use this context to automatically choose which repository to run the task on based on the repositories you've authenticated to Claude Code on the web.

As the Claude Code session progresses, Claude posts status updates back to the Slack thread. Once complete, users receive a link to the full session where they can review changes, along with a direct link to open a pull request.

The feature builds on Anthropic's existing Claude for Slack integration and requires users to have access to Claude Code on the web. In practical terms, a product manager reporting a bug in Slack could tag Claude, which would then analyze the conversation context, identify the relevant code repository, investigate the issue, propose a fix, and post a pull request—all while updating the original Slack thread with its progress.

Why Anthropic is betting big on enterprise workflow integrations

The Slack integration arrives at a pivotal moment for Anthropic. Claude Code has already hit $1 billion in revenue six months since its public debut in May, according to a LinkedIn post from Anthropic's chief product officer, Mike Krieger. The coding agent continues to barrel toward scale with customers like Netflix, Spotify, and Salesforce.

The velocity of that growth helps explain why Anthropic made its first-ever acquisition earlier this month. Anthropic declined to comment on financial details. The Information earlier reported on Anthropic's bid to acquire Bun.

Bun is a breakthrough JavaScript runtime that is dramatically faster than the leading competition. As an all-in-one toolkit — combining runtime, package manager, bundler, and test runner — it's become essential infrastructure for AI-led software engineering, helping developers build and test applications at unprecedented velocity.

Since becoming generally available in May 2025, Claude Code has grown from its origins as an internal engineering experiment into a critical tool for many of the world's category-leading enterprises, including Netflix, Spotify, KPMG, L'Oreal, and Salesforce — and Bun has been key in helping scale its infrastructure throughout that evolution.

The acquisition signals that Anthropic views Claude Code not as a peripheral feature but as a core business line worth substantial investment. The Slack integration extends that bet, positioning Claude Code as an ambient presence in the workspaces where engineering decisions actually get made.

According to an Anthropic spokesperson, companies including Rakuten, Novo Nordisk, Uber, Snowflake, and Ramp now use Claude Code for both professional and novice developers. Rakuten, the Japanese e-commerce giant, has reportedly reduced software development timelines from 24 days to just 5 days using the tool — a 79% reduction that illustrates the productivity claims Anthropic has been making.

Claude Code's rapid rise from internal experiment to billion-dollar product

The Slack launch is the latest in a rapid series of Claude Code expansions. In late November, Claude Code was added to Anthropic's desktop apps including the Mac version. Claude Code was previously limited to mobile apps and the web. It allows software engineers to code, research, and update work with multiple local and remote sessions running at the same time.

That release accompanied Anthropic's unveiling of Claude Opus 4.5, its newest and most capable model. Claude Opus 4.5 is available today on the company's apps, API, and on all three major cloud platforms. Pricing is $5/$25 per million tokens — making Opus-level capabilities accessible to even more users, teams, and enterprises.

The company has also invested heavily in the developer infrastructure that powers Claude Code. In late November, Anthropic released three new beta features for tool use: Tool Search Tool, which allows Claude to use search tools to access thousands of tools without consuming its context window; Programmatic Tool Calling, which allows Claude to invoke tools in a code execution environment reducing the impact on the model's context window; and Tool Use Examples, which provides a universal standard for demonstrating how to effectively use a given tool.

The Model Context Protocol (MCP) is an open standard for connecting AI agents to external systems. Connecting agents to tools and data traditionally requires a custom integration for each pairing, creating fragmentation and duplicated effort that makes it difficult to scale truly connected systems. MCP provides a universal protocol — developers implement MCP once in their agent and it unlocks an entire ecosystem of integrations.

Inside Anthropic's own AI transformation: what happens when engineers use Claude all day

Anthropic has been unusually transparent about how its own engineers use Claude Code — and the findings offer a preview of broader workforce implications. In August 2025, Anthropic surveyed 132 engineers and researchers, conducted 53 in-depth qualitative interviews, and studied internal Claude Code usage data to understand how AI use is changing work at the company.

Employees self-reported using Claude in 60% of their work and achieving a 50% productivity boost, a 2-3x increase from this time last year. This productivity looks like slightly less time per task category, but considerably more output volume.

Perhaps most notably, 27% of Claude-assisted work consists of tasks that wouldn't have been done otherwise, such as scaling projects, making nice-to-have tools like interactive data dashboards, and exploratory work that wouldn't be cost-effective if done manually.

The internal research also revealed how Claude is changing the nature of engineering collaboration. The maximum number of consecutive tool calls Claude Code makes per transcript increased by 116%. Claude now chains together 21.2 independent tool calls without need for human intervention versus 9.8 tool calls from six months ago.

The number of human turns decreased by 33%. The average number of human turns decreased from 6.2 to 4.1 per transcript, suggesting that less human input is necessary to accomplish a given task now compared to six months ago.

But the research also surfaced tensions. One prominent theme was that Claude has become the first stop for questions that once went to colleagues. "It has reduced my dependence on [my team] by 80%, [but] the last 20% is crucial and I go and talk to them," one engineer explained. Several engineers said they "bounce ideas off" Claude, similar to interactions with human collaborators.

Others described experiencing less interaction with colleagues. Some appreciate the reduced social friction, but others resist the change or miss the older way of working: "I like working with people and it is sad that I 'need' them less now."

How Anthropic stacks up against OpenAI, Google, and Microsoft in the enterprise AI race

Anthropic is not alone in racing to capture the enterprise coding market. OpenAI, Google, and Microsoft (through GitHub Copilot) are all pursuing similar integrations. The Slack launch gives Anthropic a presence in one of the most widely-used enterprise communication platforms — Slack claims over 750,000 organizations use its software.

The deal comes as Anthropic pursues a more disciplined growth path than rival OpenAI, focusing on enterprise customers and coding workloads. Internal financials reported by The Wall Street Journal show Anthropic expects to break even by 2028 — two years earlier than OpenAI, which continues to invest heavily in infrastructure as it expands into video, hardware, and consumer products.

The move also marks an increased push into developer tooling. Anthropic has recently seen backing from some of tech's biggest titans. Microsoft and Nvidia pledged up to $15 billion in fresh investment in Anthropic last month, alongside a $30 billion commitment from Anthropic to run Claude Code on Microsoft's cloud. This is in addition to the $8 billion invested from Amazon and $3 billion from Google.

The cross-investment from both Microsoft and Google — fierce competitors in the cloud and AI spaces — highlights how valuable Anthropic's enterprise positioning has become. By integrating with Slack (which is owned by Salesforce), Anthropic further embeds itself in the enterprise software ecosystem while remaining platform-agnostic.

What the Slack integration means for developers — and whether they can trust it

For engineering teams, the Slack integration promises to collapse the distance between problem identification and problem resolution. A bug report in a Slack channel can immediately trigger investigation. A feature request can spawn a prototype. A code review comment can generate a refactor.

But the integration also raises questions about oversight and code quality. Most Anthropic employees use Claude frequently while reporting they can "fully delegate" only 0-20% of their work to it. Claude is a constant collaborator but using it generally involves active supervision and validation, especially in high-stakes work — versus handing off tasks requiring no verification at all.

Some employees are concerned about the atrophy of deeper skillsets required for both writing and critiquing code — "When producing output is so easy and fast, it gets harder and harder to actually take the time to learn something."

The Slack integration, by making Claude Code invocation as simple as an @mention, may accelerate both the productivity benefits and the skill-atrophy concerns that Anthropic's own research has documented.

The future of coding may be conversational—and Anthropic is racing to prove it

The beta launch marks the beginning of what Anthropic expects will be a broader rollout, with documentation forthcoming for teams looking to deploy the integration and refinements planned based on user feedback during the research preview phase.

For Anthropic, the Slack integration is a calculated bet on a fundamental shift in how software gets written. The company is wagering that the future of coding will be conversational — that the walls between where developers talk about problems and where they solve them will dissolve entirely. The companies that win enterprise AI, in this view, will be the ones that meet developers not in specialized tools but in the chat windows they already have open all day.

Whether that vision becomes reality will depend on whether Claude Code can deliver enterprise-grade reliability while maintaining the security that organizations demand. The early returns are promising: a billion dollars in revenue, a roster of Fortune 500 customers, and a growing ecosystem of integrations suggest Anthropic is onto something real.

But in one of Anthropic's own internal interviews, an engineer offered a more cautious assessment of the transformation underway: "Nobody knows what's going to happen… the important thing is to just be really adaptable."

In the age of AI coding agents, that may be the only career advice that holds up.