feat(eve): add stateful Slack threadReplies hook

[benpankow]

Summary

This exploratory PR adds a durable, in-workflow policy for deciding whether eve should respond to a reply in an active Slack thread.

1. Respond only to explicit mentions

This remains the default:

export default slackChannel({
  credentials: connectSlackCredentials("slack/my-agent"),
});

2. Respond to every human reply in active eve threads

export default slackChannel({
  credentials: connectSlackCredentials("slack/my-agent"),
  threadReplies: true,
});

Messages outside threads with an active eve session remain ignored.

3. Track custom thread-reply state

threadReplies can hold durable state and define an onReply policy that runs inside the hydrated session workflow. For example, this policy stops responding after someone else is mentioned, then resumes when eve is mentioned directly:

type ThreadReplyState = "followingThread" | "ignoringThread";

export default slackChannel({
  credentials: connectSlackCredentials("slack/my-agent"),
  threadReplies: {
    initialState: "followingThread" as ThreadReplyState,
    onReply(message, ctx) {
      if (ctx.isBotMentioned) {
        return {
          respond: true,
          state: "followingThread",
        };
      }

      if (ctx.state === "ignoringThread") {
        return {
          respond: false,
          state: ctx.state,
        };
      }

      const mentionsSomeone = /<@[A-Z0-9]+(?:\|[^>]+)?>/.test(message.text);

      return mentionsSomeone
        ? {
            respond: false,
            state: "ignoringThread",
          }
        : {
            respond: true,
            state: ctx.state,
          };
    },
  },
});

Returning respond: false skips only that reply. The eve session remains active and onReply runs again for a later reply.

4. Classify ambiguous replies

onReply can also make a small structured AI SDK call to decide whether a thread reply needs a response:

import { generateText, Output } from "ai";
import { z } from "zod";

export default slackChannel({
  credentials: connectSlackCredentials("slack/my-agent"),
  threadReplies: {
    async onReply(message, ctx) {
      if (ctx.isBotMentioned) {
        return { respond: true };
      }

      await ctx.thread.refresh();
      const conversation = ctx.thread.recentMessages
        .slice(-12)
        .map((entry) =>
          `${entry.isMe ? "agent" : (entry.user ?? "unknown")}: ${entry.text}`,
        )
        .join("\n");

      const { output } = await generateText({
        model: "google/gemini-3.1-flash-lite",
        system:
          "Decide whether the final Slack message expects the agent to answer.",
        prompt: conversation,
        output: Output.object({
          schema: z.object({ respond: z.boolean() }),
        }),
        temperature: 0,
        maxOutputTokens: 100,
        maxRetries: 0,
        timeout: 1_500,
      });

      return { respond: output.respond };
    },
  },
});

Test Plan

• Added unit tests for default mention-only and threadReplies: true behavior.
• Added unit tests for arbitrary durable thread-reply state and explicit-mention transitions.
• Added workflow coverage for running onReply policies inside hydrated eve context.
• Manually verified the handoff behavior with a deployed Slack agent.

[vercel]

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Project	Deployment	Actions	Updated (UTC)
eve-docs	Ready	Preview, Comment, Open in v0	Jul 27, 2026 9:59pm
eve-docs-1644	Ready	Preview, Comment, Open in v0	Jul 27, 2026 9:59pm
eve-docs-4759	Ready	Preview, Comment, Open in v0	Jul 27, 2026 9:59pm

[github-actions]

Bundle + Package Summary: apps/fixtures/weather-agent

Key takeaways

• No notable deltas vs main (6e9e283).

Delta vs main (6e9e283)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	7.42 MB	7.42 MB	+2.4 kB ⚠️
Package	Unpacked publish size	27.93 MB	27.94 MB	+8.4 kB ⚠️
Package	Installed footprint	67.08 MB	67.09 MB	+8.4 kB ⚠️
Package	Published files	2786	2786	0
Package	Installed files	6026	6026	0
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	14.63 MB	14.63 MB	+706 B ⚠️
Runtime	Public routes	11	11	0

Changed function payloads vs main (6e9e283) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/__server.func	changed	7.32 MB	7.32 MB	+353 B ⚠️	none
functions/.well-known/workflow/v1/flow.func	changed	7.32 MB	7.32 MB	+353 B ⚠️	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	105.49 MB	105.50 MB	+8.4 kB ⚠️
Installed packages	122	122	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	42.21 MB	42.22 MB	+8.4 kB ⚠️
devDependency package bytes	5.04 MB	5.04 MB	0 B ➖

eve init dependency changes vs main (6e9e283)

dependencies

• Changed: eve@file:eve-0.27.7.tgz -> eve@file:eve-0.27.8.tgz

Build Metadata

• Preset: vercel
• Nitro: nitro@3.0.260610-beta
• Output directory: apps/fixtures/weather-agent/.vercel/output
• Build metadata timestamp: 2026-07-27T22:00:31.755Z
• Route aliases: 11 public, 1 internal (12 total aliases)
• Vercel routes in config: 14
• Severity legend: 🔴 dominant/large, 🟠 notable, 🟡 watch, ⚪ small

Package Drill-Down

Package Details

• Package: eve@0.27.8
• Package directory: packages/eve
• Tarball: 7.42 MB (eve-0.27.8.tgz)
• Unpacked payload: 27.94 MB across 2786 published files
• Installed footprint: 67.09 MB across 6026 installed files
• Installed root package: 26.65 MB
• Installed dependencies: 40.44 MB
• Runtime dependencies: 1
• Peer dependencies: 5 (4 optional)

Installed footprint is measured from an isolated temporary npm install of the packed tarball.

Heavy installed dependencies

• eve: 26.65 MB (39.7%)
• @rolldown/binding-linux-x64-gnu: 18.96 MB (28.3%)
• ai: 6.43 MB (9.6%)
• zod: 5.04 MB (7.5%)
• nitro: 2.41 MB (3.6%)

Publish payload breakdown

Published file size
🔴 dist/src/compiled/shadcn-registry/index.js       [########################] 13.15 MB 47.1%
🟠 dist/src/compiled/experimental-ai-sdk-code-mo... [###.....................] 1.51 MB 5.4%
🟡 dist/src/compiled/@vercel/sandbox/index.js       [#.......................] 632.4 kB 2.3%
🟡 dist/src/compiled/_chunks/workflow/undici-C2Z... [#.......................] 502.4 kB 1.8%
🟡 dist/src/compiled/@chat-adapter/slack/index.js   [#.......................] 440.5 kB 1.6%
🔴 Other published files                            [#####################...] 11.70 MB 41.9%

Installed footprint breakdown

Installed package size
🔴 eve                             [########################] 26.65 MB 39.7%
🔴 @rolldown/binding-linux-x64-gnu [#################.......] 18.96 MB 28.3%
🔴 ai                              [######..................] 6.43 MB 9.6%
🔴 zod                             [#####...................] 5.04 MB 7.5%
🟠 nitro                           [##......................] 2.41 MB 3.6%
🟡 @ai-sdk/provider-utils          [#.......................] 852.0 kB 1.3%
🔴 Other installed packages        [######..................] 6.75 MB 10.1%

Runtime dependencies (1)

Package	Range	Notes
nitro	3.0.260610-beta

Peer dependencies (5)

Package	Range	Notes
@opentelemetry/api	^1.0.0	optional peer
ai	catalog:
braintrust	^3.0.0	optional peer
just-bash	^3.0.0	optional peer
microsandbox	^0.5.0	optional peer

eve init install drill-down

eve init install details

• Command: eve init my-agent
• Package manager: npm
• Installed footprint: 105.50 MB across 7894 installed files
• Installed packages: 122 total (116 transitive-only)
• dependencies: 4 direct packages totaling 42.22 MB
• devDependencies: 2 direct packages totaling 5.04 MB
• Other transitive package files: 58.24 MB

Installed footprint is measured from an isolated temporary eve init my-agent using the current packed eve tarball.

Heavy installed dependencies

• @typescript/typescript-linux-x64: 27.95 MB (26.5%)
• eve: 26.65 MB (25.3%)
• @rolldown/binding-linux-x64-gnu: 18.96 MB (18.0%)
• zod: 9.00 MB (8.5%)
• ai: 6.43 MB (6.1%)

Installed footprint breakdown

Installed package size
🔴 @typescript/typescript-linux-x64 [########################] 27.95 MB 26.5%
🔴 eve                              [#######################.] 26.65 MB 25.3%
🔴 @rolldown/binding-linux-x64-gnu  [################........] 18.96 MB 18.0%
🔴 zod                              [########................] 9.00 MB 8.5%
🔴 ai                               [######..................] 6.43 MB 6.1%
🟠 @types/node                      [##......................] 2.54 MB 2.4%
🔴 Other installed packages         [############............] 13.97 MB 13.2%

dependencies (4)

Package	Range	Installed size	Share
@vercel/connect	0.4.2	135.8 kB	0.1%
ai	^7.0.34	6.43 MB	6.1%
eve	file:eve-0.27.8.tgz	26.65 MB	25.3%
zod	4.4.3	9.00 MB	8.5%

devDependencies (2)

Package	Range	Installed size	Share
@types/node	24.x	2.54 MB	2.4%
typescript	7.0.2	2.50 MB	2.4%

Function Drill-Down

Payload Size Graph

Unique function payload size and share of total
🔴 functions/.well-known/workflow/v1/flow.func     [########################] 7.32 MB 50.0%
🔴 functions/__server.func                         [########################] 7.32 MB 50.0%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 7.32 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	7.32 MB
Function files	7.32 MB across 43 files
Traced dependencies	0 B
Signal	🟠 Bundled file _chunks/runtime-artifacts.mjs is 1.57 MB (21.5%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 _chunks/runtime-artifacts.mjs   [###############.........] 1.57 MB 21.5%
🟠 index.mjs                       [###########.............] 1.17 MB 16.0%
🟡 _chunks/world-vercel.mjs        [#########...............] 900.3 kB 12.3%
🟡 _chunks/sandbox.mjs             [#######.................] 767.6 kB 10.5%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.5 kB 5.9%
🟠 Other bundled files             [########################] 2.47 MB 33.8%

🧾 Vercel Config

{
  "handler": "index.mjs",
  "launcherType": "Nodejs",
  "shouldAddHelpers": false,
  "supportsResponseStreaming": true,
  "runtime": "nodejs24.x",
  "maxDuration": "max",
  "experimentalTriggers": [
    {
      "type": "queue/v2beta",
      "topic": "__eve776561746865722d6167656e74_wkf_workflow_*",
      "consumer": "default",
      "retryAfterSeconds": 5,
      "initialDelaySeconds": 0
    }
  ],
  "environment": {
    "WORKFLOW_PRECONDITION_GUARD": "1"
  }
}

---

🟠 functions/__server.func • 10 public routes, 1 internal alias • 7.32 MB

Metric	Value
Public routes	/ /eve/v1/callback/[token] /eve/v1/connections/[name]/callback/[token] /eve/v1/health /eve/v1/info /eve/v1/session /eve/v1/session/[sessionId] /eve/v1/session/[sessionId]/cancel /eve/v1/session/[sessionId]/stream /eve/v1/session/reset
Internal aliases	/__server
Runtime	nodejs24.x
Handler	index.mjs
Payload	7.32 MB
Function files	7.32 MB across 43 files
Traced dependencies	0 B
Signal	🟠 Bundled file _chunks/runtime-artifacts.mjs is 1.57 MB (21.5%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 _chunks/runtime-artifacts.mjs   [###############.........] 1.57 MB 21.5%
🟠 index.mjs                       [###########.............] 1.17 MB 16.0%
🟡 _chunks/world-vercel.mjs        [#########...............] 900.3 kB 12.3%
🟡 _chunks/sandbox.mjs             [#######.................] 767.6 kB 10.5%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.5 kB 5.9%
🟠 Other bundled files             [########################] 2.47 MB 33.8%

🧾 Vercel Config

{
  "handler": "index.mjs",
  "launcherType": "Nodejs",
  "shouldAddHelpers": false,
  "supportsResponseStreaming": true,
  "runtime": "nodejs24.x"
}

Build Timing: e2e/fixtures/agent-tools-sandbox

This is an informational timing measurement inside eve build, from preflight through publication. Output-size measurement and profile writing are excluded.

Build mode: deployable Vercel build with sandbox template prewarm included.

• Build pipeline: 1.99 s -> 1.77 s (-213.9 ms) vs main (6e9e283).
• Timing is informational: shared GitHub runners are too variable for a hard timing budget.

Detailed phase timings vs `main (6e9e283)`

Phase	Baseline	Current	Delta
extension.check	1.0 ms	1.1 ms	+0.1 ms
project.resolve	0.6 ms	0.7 ms	+0.1 ms
workspace.create	0.7 ms	0.8 ms	+0.1 ms
host.prepare	364.1 ms	156.8 ms	-207.3 ms
vercel.service-prefix.resolve	2.0 ms	2.6 ms	+0.6 ms
nitro.create	204.8 ms	214.0 ms	+9.2 ms
sandbox.prewarm	279.1 ms	244.0 ms	-35.1 ms
nitro.cache.prepare	0.3 ms	0.3 ms	0.0 ms
nitro.prepare	0.8 ms	0.8 ms	0.0 ms
nitro.public-assets	0.8 ms	0.8 ms	0.0 ms
nitro.prerender	0.5 ms	0.5 ms	0.0 ms
nitro.bundle	1.12 s	1.14 s	+18.7 ms
nitro.cache.write	0.4 ms	0.4 ms	0.0 ms
agent-summary.emit	0.5 ms	0.5 ms	0.0 ms
nitro.close	0.1 ms	0.1 ms	0.0 ms
output.publish	3.5 ms	3.4 ms	-0.1 ms
workspace.remove	2.3 ms	2.3 ms	0.0 ms

[vercel]

Additional Suggestion:

Commit 43d6f6f removed the documented public isSubscribed() helper from the Slack onMessage context, breaking a first-party scaffold template and diverging from the Teams channel.