refactor(client): share one conversation client across the store and hooks

[OwenKephart]

Summary

EveAgentStore, the framework hooks, and the eve dev TUI each tracked session lifecycle on their own. Store decisions came from raw events, and subagent following existed only in the TUI. The store now delegates the root stream, deduplication, cursors, projections, and agent-session following to one ConversationClient. It keeps a canonical ConversationState (messages, root turns, input requests, tasks, and agent sessions) next to a custom reducer's data.

A turn held by working tasks stays streaming with turns[turnId].waiting set, and the store accepts answers while a turn runs. followSubagents: true follows each agent tool's session into conversation.agents; it is off by default. The store also gains a client option plus compact(), clear(), and retire(); retire() needs a store-owned session and rejects for a caller-supplied session.

Breaking: default hooks return ConversationState instead of EveMessageData.

On top of #3878; #3880 moves the TUI onto this store, and #3986 later backs ConversationState's lifecycle with the session projection #4044 adds. Stack: #3878 → #3879 → #3880 → #3965 → #4018 → #4044 → #3986, with #3977 on top. The client design is in #3922; the server design is in research/turn-state.md (#4018) and research/session-stream-contract.md (#4044).

Bugs fixed

• Sending a second message while the first was still creating the session threw "A session is required before opening its stream."
• When one model step asked to approve two tools, approving the first left the store busy, since the server sends no boundary until the batch completes. The store and web chat scaffold refused answers while busy, so the second approval could never be answered.
• In that partial batch, the approval that was already approved became clickable again after an unrelated turn ended, because the scaffold only saw an answer once the whole batch resolved.
• Answering a request the server had already settled left the store submitted forever. It now rejects locally with "already answered".
• A steered message appeared below the reply it steered until the server confirmed it.
• With a slow prepareSend, the user's message didn't appear until it resolved.
• When two callback-backed authorizations for the same connection were pending, the first completion cleared both. The session looked idle while the second was still waiting.
• MessageResponse.result().inputRequests listed requests that had already settled within the same response.
• A steered message's send() resolved when its turn asked for a callback-backed sign-in, instead of waiting for the callback like an ordinary send.

Out of scope, on the server side:

• A partially answered approval batch still sends no boundary, so the UI shows the agent as working until the batch completes.
• When an agent tool starts two parallel subagents that each need approval, both approvals reach the root, but the answer to the first is dropped. That task never settles and the root turn stays held. The same two approvals directly under the root settle normally. fix(subagents): route answers to every batch a subagent has open #3941 fixes this on the server.

Validation

• Rebased onto main at e9dd418: tsc passes, and the unit suite passes at this branch (8,783 passed, 1 skipped) apart from the sandbox OIDC fallback test that also fails on main.

Before the rebase:

• pnpm typecheck, pnpm lint, pnpm fmt, pnpm guard:invariants, pnpm docs:check, git diff --check
• pnpm --filter eve check:web-template
• Unit suite: 799 files, 8,634 passed, 1 skipped, with the tasks stack's TUI running on this client
• Integration suite: 128 files, 978 passed
• After keeping kind on ConversationTask: tsc, pnpm guard:invariants, and unit tests for src/client and the framework hooks (22 files, 314 passed)
• Before the split, EveAgentStore against mock-model eve dev servers:
  • A two-approval batch. The second approval was accepted while the first settled, and re-answering the first was rejected locally.
  • Parallel subagent approvals, under the agent tool and directly under the root. This reproduced the server stall above and showed that followSubagents follows the agent session.

Checklist

• This change was requested or approved by a maintainer
• I ran the relevant checks from CONTRIBUTING.md
• I added tests and documentation where relevant
• I added a changeset if this touches the published eve package
• DCO sign-off passes for every commit (git commit --signoff)

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
eve-docs	Ready	Preview, v0	Sep 30, 2026 6:12pm UTC

1 Skipped Deployment

Project	Deployment	Actions	Updated
eve-pkg	Skipped	v0	Sep 30, 2026 6:12pm UTC

[github-actions]

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

Key takeaways

• No notable deltas vs refactor/client-stable-part-ids (10b054a).

Delta vs refactor/client-stable-part-ids (10b054a)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	8.44 MB	8.45 MB	+18.7 kB ⚠️
Package	Unpacked publish size	30.97 MB	31.04 MB	+71.8 kB ⚠️
Package	Installed footprint	77.78 MB	77.85 MB	+71.8 kB ⚠️
Package	Published files	3898	3908	+10
Package	Installed files	7878	7888	+10
Package	Installed package instances	33	33	0
Package	Distinct installed package names	32	32	0
Package	Installed dependency edges	51	51	0
Package	Installed optional peer edges	9	9	0
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	19.09 MB	19.09 MB	-80 B ✅
Runtime	Public routes	17	17	0

Changed function payloads vs refactor/client-stable-part-ids (10b054a) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/__server.func	changed	9.55 MB	9.55 MB	-40 B ✅	none
functions/.well-known/workflow/v1/flow.func	changed	9.55 MB	9.55 MB	-40 B ✅	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	116.07 MB	116.15 MB	+71.8 kB ⚠️
Installed packages	97	97	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	48.41 MB	48.48 MB	+71.8 kB ⚠️
devDependency package bytes	5.11 MB	5.11 MB	0 B ➖

Build Metadata

• Preset: vercel
• Nitro: nitro@3.0.260903-beta
• Output directory: apps/fixtures/weather-agent/.vercel/output
• Build metadata timestamp: 2026-09-30T18:12:07.633Z
• Route aliases: 17 public, 1 internal (18 total aliases)
• Vercel routes in config: 20
• Severity legend: 🔴 dominant/large, 🟠 notable, 🟡 watch, ⚪ small

Package Drill-Down

Package Details

• Package: eve@0.68.0
• Package directory: packages/eve
• Tarball: 8.45 MB (eve-0.68.0.tgz)
• Unpacked payload: 31.04 MB across 3908 published files
• Installed footprint: 77.85 MB across 7888 installed files
• Installed root package: 30.75 MB
• Installed dependencies: 47.10 MB
• Installed package instances: 33
• Distinct installed package names: 32
• Installed dependency edges: 51
• Installed optional peer edges: 9
• Runtime dependencies: 2
• Peer dependencies: 7 (6 optional)

Installed footprint is measured from an isolated temporary npm install of the packed tarball.
Graph metrics read only package.json files in package directories directly beneath a node_modules boundary, including nested boundaries. Each directory is one package instance; distinct names come from those manifests. Dependency edges count each unique name in dependencies or optionalDependencies per instance; optional peer edges count peerDependencies marked optional.

Heavy installed dependencies

• eve: 30.75 MB (39.5%)
• @rolldown/binding-linux-x64-gnu: 19.47 MB (25.0%)
• ai: 7.78 MB (10.0%)
• zod: 6.14 MB (7.9%)
• undici: 3.52 MB (4.5%)

Publish payload breakdown

Published file size
🔴 dist/src/compiled/shadcn-registry/index.js       [##############..........] 9.70 MB 31.3%
🟠 dist/src/compiled/@photon-ai/chat-adapter-ime... [###.....................] 2.29 MB 7.4%
🟠 dist/src/compiled/@ai-sdk/code-mode/index.js     [#.......................] 1.03 MB 3.3%
🟡 dist/src/compiled/@vercel/blob/index.js          [#.......................] 604.9 kB 1.9%
🟡 dist/src/compiled/_chunks/workflow/signal-exi... [#.......................] 514.5 kB 1.7%
🔴 Other published files                            [########################] 16.90 MB 54.5%

Installed footprint breakdown

Installed package size
🔴 eve                             [########################] 30.75 MB 39.5%
🔴 @rolldown/binding-linux-x64-gnu [###############.........] 19.47 MB 25.0%
🔴 ai                              [######..................] 7.78 MB 10.0%
🔴 zod                             [#####...................] 6.14 MB 7.9%
🟠 undici                          [###.....................] 3.52 MB 4.5%
🟠 nitro                           [#.......................] 1.89 MB 2.4%
🔴 Other installed packages        [######..................] 8.30 MB 10.7%

Runtime dependencies (2)

Package	Range	Notes
nitro	3.0.260903-beta
undici	8.9.0

Peer dependencies (7)

Package	Range	Notes
@opentelemetry/api	^1.0.0	optional peer
ai	catalog:
braintrust	^3.0.0	optional peer
chat	^4.41.0	optional peer
dd-trace	^6.13.0	optional peer
just-bash	^3.1.0	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: 116.15 MB across 9783 installed files
• Installed packages: 97 total (91 transitive-only)
• dependencies: 4 direct packages totaling 48.48 MB
• devDependencies: 2 direct packages totaling 5.11 MB
• Other transitive package files: 62.55 MB

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

Heavy installed dependencies

• eve: 30.75 MB (26.5%)
• @typescript/typescript-linux-x64: 27.95 MB (24.1%)
• @rolldown/binding-linux-x64-gnu: 19.47 MB (16.8%)
• zod: 9.76 MB (8.4%)
• ai: 7.78 MB (6.7%)

Installed footprint breakdown

Installed package size
🔴 eve                              [########################] 30.75 MB 26.5%
🔴 @typescript/typescript-linux-x64 [######################..] 27.95 MB 24.1%
🔴 @rolldown/binding-linux-x64-gnu  [###############.........] 19.47 MB 16.8%
🔴 zod                              [########................] 9.76 MB 8.4%
🔴 ai                               [######..................] 7.78 MB 6.7%
🟠 undici                           [###.....................] 3.52 MB 3.0%
🔴 Other installed packages         [#############...........] 16.93 MB 14.6%

dependencies (4)

Package	Range	Installed size	Share
@vercel/connect	2.2.0	194.7 kB	0.2%
ai	^7.0.105	7.78 MB	6.7%
eve	file:eve-0.68.0.tgz	30.75 MB	26.5%
zod	4.5.4	9.76 MB	8.4%

devDependencies (2)

Package	Range	Installed size	Share
@types/node	24.x	2.61 MB	2.3%
typescript	7.0.2	2.50 MB	2.2%

Function Drill-Down

Payload Size Graph

Unique function payload size and share of total
🔴 functions/.well-known/workflow/v1/flow.func     [########################] 9.55 MB 50.0%
🔴 functions/__server.func                         [########################] 9.55 MB 50.0%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 9.55 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	9.55 MB
Function files	9.55 MB across 111 files
Traced dependencies	0 B
Signal	🟠 Bundled file _chunks/vercel.web.mjs is 2.16 MB (22.6%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 _chunks/vercel.web.mjs                         [############............] 2.16 MB 22.6%
🟡 _libs/undici.mjs                               [######..................] 980.8 kB 10.3%
🟡 _chunks/sandbox.mjs                            [#####...................] 811.4 kB 8.5%
🟡 _chunks/compiled-artifacts-instrumentation.mjs [####....................] 756.3 kB 7.9%
🟡 _chunks/signal-exit-DZKTacNU.mjs               [###.....................] 616.2 kB 6.5%
🔴 Other bundled files                            [########################] 4.23 MB 44.3%

🧾 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 • 16 public routes, 1 internal alias • 9.55 MB

Metric	Value
Public routes	/ /.well-known/workflow/v1/webhook/[token] /eve/v1/activity/[token] /eve/v1/callback/[token] /eve/v1/connections/[name]/callback/[attemptId]/[token] /eve/v1/connections/[name]/callback/[token] /eve/v1/health /eve/v1/info /eve/v1/session /eve/v1/session/[parentSessionId]/subagents/[callId]/[childSessionId]/stream /eve/v1/session/[sessionId] /eve/v1/session/[sessionId]/cancel /eve/v1/session/[sessionId]/clear /eve/v1/session/[sessionId]/compact /eve/v1/session/[sessionId]/reset /eve/v1/session/[sessionId]/stream
Internal aliases	/__server
Runtime	nodejs24.x
Handler	index.mjs
Payload	9.55 MB
Function files	9.55 MB across 111 files
Traced dependencies	0 B
Signal	🟠 Bundled file _chunks/vercel.web.mjs is 2.16 MB (22.6%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 _chunks/vercel.web.mjs                         [############............] 2.16 MB 22.6%
🟡 _libs/undici.mjs                               [######..................] 980.8 kB 10.3%
🟡 _chunks/sandbox.mjs                            [#####...................] 811.4 kB 8.5%
🟡 _chunks/compiled-artifacts-instrumentation.mjs [####....................] 756.3 kB 7.9%
🟡 _chunks/signal-exit-DZKTacNU.mjs               [###.....................] 616.2 kB 6.5%
🔴 Other bundled files                            [########################] 4.23 MB 44.3%

🧾 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: 3.22 s -> 3.21 s (-10.0 ms) vs refactor/client-stable-part-ids (10b054a).
• Timing is informational: shared GitHub runners are too variable for a hard timing budget.

Detailed phase timings vs `refactor/client-stable-part-ids (10b054a)`

Phase	Baseline	Current	Delta
extension.check	12.4 ms	12.8 ms	+0.4 ms
project.resolve	3.1 ms	5.3 ms	+2.2 ms
workspace.create	0.6 ms	3.1 ms	+2.5 ms
host.prepare	608.4 ms	543.0 ms	-65.4 ms
vercel.service-prefix.resolve	1.1 ms	1.2 ms	+0.1 ms
nitro.create	415.7 ms	402.2 ms	-13.5 ms
sandbox.prewarm	323.8 ms	326.6 ms	+2.8 ms
nitro.cache.prepare	0.2 ms	0.2 ms	0.0 ms
nitro.prepare	0.8 ms	0.6 ms	-0.2 ms
nitro.public-assets	0.5 ms	0.5 ms	0.0 ms
nitro.prerender	0.4 ms	0.3 ms	-0.1 ms
nitro.bundle	1.72 s	1.78 s	+62.5 ms
nitro.cache.write	0.2 ms	0.2 ms	0.0 ms
vercel.workflow-function.materialize	60.9 ms	60.5 ms	-0.4 ms
agent-summary.emit	0.6 ms	0.6 ms	0.0 ms
connect-manifest.emit	0.2 ms	0.2 ms	0.0 ms
nitro.close	0.1 ms	0.1 ms	0.0 ms
output.publish	3.8 ms	4.5 ms	+0.7 ms
workspace.remove	2.3 ms	2.4 ms	+0.1 ms