feat: log AI coding agents in user-agent, telemetry, and tracing by mwbrooks · Pull Request #550 · slackapi/slack-cli

mwbrooks · 2026-05-15T22:44:26Z

Changelog

When the CLI is invoked by an AI coding agent, the HTTP User-Agent header now includes an AI-Agent suffix identifying the agent. Developers can see the user agent in the --verbose debug logs.
# No AI Agent
$ slack version --verbose
# user_agent: slack-cli/v4.0.1 (os: darwin)

# Pretending we are Claude
$ CLAUDECODE=1 CLAUDE_CODE_ENTRYPOINT=cli slack version --verbose
# user_agent: slack-cli/v4.0.1 (os: darwin) AI-Agent (name: claude-code, entry: cli)

Summary

This pull request adds detection of AI coding agents and surfaces the detected agent across HTTP requests, telemetry, and tracing.

Format:

slack-cli/v4.0.1 (os: darwin) AI-Agent (name: claude-code, entry: cli)
slack-cli/v4.0.1 (os: darwin) AI-Agent (name: claude-code, entry: desktop)
slack-cli/v4.0.1 (os: darwin) AI-Agent (name: codex)

Analytics:

We can look up "AI-Agent" to know if the CLI was run by an agent.
We can look up the specific agent used by name:.
We have the ability to log additional agent information when available (e.g. entry:) but it's very limited today.

Detected AI agents environment variables:

CLAUDECODE → claude-code
- CLAUDE_CODE_ENTRYPOINT → cli or desktop or possibly even vscode
CODEX_CI → codex
GEMINI_CLI → gemini-cli
- This could be gemini if we want, but since the env var is specific the CLI we may want to take advantage of that
CLINE_ACTIVE → cline
CURSOR_AGENT → cursor
AGENT
- Generic fallback that's emerging as the common env var for agents

When detected:

The User-Agent header on all API requests gets an AI-Agent (name:<name>, [entry:<entrypoint>]) addition
Logstash telemetry events include an agent field in the context
Jaeger tracing gets an ai_agent span tag
Verbose output prints the full user-agent at startup

Testing

# Test Claude Code WITH an entry value
$ CLAUDECODE=1 CLAUDE_CODE_ENTRYPOINT=cli slack version --verbose
# [2026-05-15 15:29:06] user_agent: slack-cli/v4.0.1 (os: darwin) AI-Agent (name: claude-code, entry: cli)
# ...
# [2026-05-15 15:40:26] FlushToLogstash will POST https://dev.slackb.com/events/cli payload: [{"context":{"agent":"claude-code","arch":"arm64,...

# Test Claude Code WITHOUT an entry value
$ CLAUDECODE=1 slack version --verbose
# [2026-05-15 15:29:06] user_agent: slack-cli/v4.0.1 (os: darwin) AI-Agent (name: claude-code)
# ...
# [2026-05-15 15:40:26] FlushToLogstash will POST https://dev.slackb.com/events/cli payload: [{"context":{"agent":"claude-code","arch":"arm64,...

Requirements

I've read and understood the Contributing Guidelines and have done my best effort to follow them.
I've read and agree to the Code of Conduct.

When the Slack CLI is invoked by an AI coding agent (Claude Code, Codex, Gemini CLI, Cline, Cursor, Goose, Amp, or others), detect the agent via environment variables and append an AI-Agent product token to the HTTP user-agent header. Also propagates the agent name to telemetry events and Jaeger tracing spans. User-Agent format: slack-cli/2.38.1 (os: darwin) AI-Agent (name=claude-code, entry=cli)

Removes duplicate detectAIAgentName/detectAgentName helpers from main.go and tracking.go in favor of useragent.DetectName().

codecov · 2026-05-15T22:48:19Z

Codecov Report

❌ Patch coverage is 85.71429% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.62%. Comparing base (afcb85d) to head (3c3c624).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/useragent/useragent.go	87.09%	4 Missing ⚠️
main.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #550      +/-   ##
==========================================
- Coverage   71.64%   71.62%   -0.02%     
==========================================
  Files         225      226       +1     
  Lines       19074    19104      +30     
==========================================
+ Hits        13665    13684      +19     
- Misses       4202     4211       +9     
- Partials     1207     1209       +2

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mwbrooks

Comments for the kind reviewers! 🖊️

mwbrooks · 2026-05-15T22:51:58Z

 		rootCmd.SetContext(ctx)
 		// Debug logging
 		clients.IO.PrintDebug(ctx, "system_id: %s", clients.Config.SystemID)
+		clients.IO.PrintDebug(ctx, "user_agent: %s", useragent.BuildUserAgent(version.Raw()))


note: This is a new addition to our verbose logs. For a while, I've wanted to see our user-agent which is used for each API request. This may also be helpful when diagnosing user reported issues.

mwbrooks · 2026-05-15T22:54:55Z

 	span.SetTag("hashed_hostname", ioutils.GetHostname())
 	span.SetTag("slack_cli_process", processName)
+	if agentName := useragent.DetectName(); agentName != "" {
+		span.SetTag("ai_agent", agentName)


note: I chose ai_agent instead of agent because it's less ambiguous and more specific that it's an AI "agent".

mwbrooks · 2026-05-15T22:55:48Z


 // EventContext contains information / metadata about the CLI session
 type EventContext struct {
+	AIAgent          string   `json:"ai_agent,omitempty"`


note: I chose ai_agent instead of agent because it's less ambiguous and more specific that it's an AI "agent".

zimeg

@mwbrooks Let's uncover patterns to encourage whenever's right 📊

The comments I leave aren't blocking so please do ignore but some of these are questions I have about user agent itself? Thanks for landing this much.

zimeg · 2026-05-15T23:52:16Z

+	ua := fmt.Sprintf("slack-cli/%s (os: %s)", cliVersion, runtime.GOOS)
+	if agent := Detect(); agent != nil {
+		var parts []string
+		parts = append(parts, "name="+agent.Name)


Suggested change

parts = append(parts, "name="+agent.Name)

parts = append(parts, "name: "+agent.Name)

☎️ question: A ":" separator might match the os adjacent but I understand can make queries more difficult. If this was intentional please ignore but I did want to ask?

praise: @zimeg great catch, thank you! This was my mistake and we should definitely be using : not =. Commit a3c4167

zimeg · 2026-05-15T23:52:50Z

+// BuildUserAgent constructs the HTTP User-Agent header value for the CLI. If an
+// AI agent is detected, an "AI-Agent (name=..., entry=...)" suffix is appended.


📚 quibble: It'd be helpful to have a full example here but no blocker!

@zimeg Solid suggestion. Commit 7a633af adds a couple examples to show the various combinations that can appear.

zimeg · 2026-05-15T23:54:15Z

+
+// DetectName returns the normalized name of the detected AI agent, or an empty
+// string if no agent is detected.
+func DetectName() string {


Suggested change

func DetectName() string {

func DetectHarness() string {

🪬 question: Forgive these words but this is an unusual export for the value found I think but I also admit to not being so familiar with practices encouraged here!

🌃 ramble: It does seem solid if we're framing this as the... actual user agent though? I'm understanding more I hope!

Thanks for catching these names @zimeg! Commit 35b6cfc updates the function (and a few variable) names to be AIAgent instead of Detect. This was a result of a last minute refactor where I renamed a agent/agent.go package to be useragent/useragent.go.

srtaalej

very cool addition ⭐ ⭐ ⭐

srtaalej · 2026-05-18T15:10:59Z

+		if agent.Entry != "" {
+			parts = append(parts, "entry="+agent.Entry)
+		}
+		ua += " AI-Agent (" + strings.Join(parts, ", ") + ")"


Suggested change

ua += " AI-Agent (" + strings.Join(parts, ", ") + ")"

ua += " AI-Agent: (" + strings.Join(parts, ", ") + ")"

could we have a : separator here to to match the user_agent also 🤔 if unintentional ^^ ofc

Good suggestion @srtaalej - I see where you're coming from in that it may improve parsing. However, most user-agent strings would not add a colon there.

User-Agent strings are a loose standard, but the general format is Some-Name/<Version> (metadata...). Since we can't reliably get a version, I'm just going with the high-level "AI-Agent" and letting the metadata section describe the details. The metadata section is something (key1: value1, key2: value2, ...) and something (value1; value2...). We've adopted the key/value pair because it's easier to parse reliably.

Here's a mega list of User-Agents to give a sense of the messy world of UA:
https://gist.github.com/pzb/b4b6f57144aea7827ae4

Use "name: value" / "entry: value" to match the existing "(os: linux)" segment instead of "name=value" / "entry=value".

Show concrete User-Agent strings for both the no-agent and AI-agent-detected cases so readers can see the full assembled header at a glance.

…Name The package was renamed from agent to useragent and generalized to build the full User-Agent string. The old Detect / DetectName names were ambiguous in the new package context (detect what?). Rename to make their purpose explicit, and rename internal "agent" variables to "aiAgent" to avoid shadowing the broader user-agent concept.

mwbrooks · 2026-05-19T21:12:22Z

@zimeg @srtaalej Thanks for the thorough reviews! This PR is coming in at a higher quality level thanks to your feedback! 🙇🏻 🚀

mwbrooks added 6 commits May 15, 2026 14:22

refactor: extract DetectName() into useragent package

e172f13

Removes duplicate detectAIAgentName/detectAgentName helpers from main.go and tracking.go in favor of useragent.DetectName().

docs: add godoc comments to useragent package functions

ce067b0

fix: align test function names with Test_Package_Method convention

4251b27

chore: fix gofmt formatting in import blocks

61ead39

feat: print user-agent in verbose debug output during startup

dfb062c

mwbrooks self-assigned this May 15, 2026

mwbrooks added code health M-T: Test improvements and anything that improves code health semver:patch Use on pull requests to describe the release version increment labels May 15, 2026

mwbrooks added this to the Next Release milestone May 15, 2026

mwbrooks changed the title ~~feat: detect AI coding agents in user-agent, telemetry, and tracing~~ feat: log AI coding agents in user-agent, telemetry, and tracing May 15, 2026

mwbrooks added 2 commits May 15, 2026 15:55

refactor: rename logstash field from agent to ai_agent for consistency

eedcf9d

chore: alphabetize test functions and rename logstash field to ai_agent

96cd3e3

mwbrooks commented May 15, 2026

View reviewed changes

mwbrooks added changelog Use on updates to be included in the release notes enhancement M-T: A feature request for new functionality and removed code health M-T: Test improvements and anything that improves code health labels May 15, 2026

style: remove stray blank line in raw_request.go import block

5bd7a8c

mwbrooks marked this pull request as ready for review May 15, 2026 23:12

mwbrooks requested a review from a team as a code owner May 15, 2026 23:12

Merge branch 'main' into mwbrooks-track-ai-agent

082c836

zimeg approved these changes May 15, 2026

View reviewed changes

srtaalej approved these changes May 18, 2026

View reviewed changes

mwbrooks added 4 commits May 19, 2026 09:58

style: format AI-Agent user-agent properties with colons

a3c4167

Use "name: value" / "entry: value" to match the existing "(os: linux)" segment instead of "name=value" / "entry=value".

docs: add full user-agent examples to BuildUserAgent godoc

7a633af

Show concrete User-Agent strings for both the no-agent and AI-agent-detected cases so readers can see the full assembled header at a glance.

Merge branch 'main' into mwbrooks-track-ai-agent

3c3c624

mwbrooks merged commit fe2457c into main May 19, 2026
10 checks passed

mwbrooks deleted the mwbrooks-track-ai-agent branch May 19, 2026 21:12

	parts = append(parts, "name="+agent.Name)
	parts = append(parts, "name: "+agent.Name)

		// BuildUserAgent constructs the HTTP User-Agent header value for the CLI. If an
		// AI agent is detected, an "AI-Agent (name=..., entry=...)" suffix is appended.

	ua += " AI-Agent (" + strings.Join(parts, ", ") + ")"
	ua += " AI-Agent: (" + strings.Join(parts, ", ") + ")"

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mwbrooks commented May 15, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Changelog

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mwbrooks commented May 19, 2026

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mwbrooks commented May 15, 2026 •

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