test(e2e): add background task golden paths

[ruiconti]

Continuation of #1724 (closed to change base; content identical).

What

• Add a deterministic fixture-tasks entry with experimental.tasks enabled.
• Cover the background-task golden paths: one-step fanout of ten tasks, continued parent interaction while those tasks run, and lifecycle updates from every task back to the parent session.
• Keep regression coverage for task HITL routing, concurrent session-create idempotency, input-batch ordering, and child-task exclusivity.
• Run the fixture with an authored mockModel in every suite so the same orchestration executes against each workflow world without provider planning variance.

Golden paths

Path	End-to-end assertion
Many-task fanout	One model step starts ten background child sessions and returns ten distinct task receipts.
Parent interactivity	All ten tasks first block on unreleased child approvals; the parent then accepts a normal follow-up and returns an ordinary tool-free reply.
Fanout parent updates	After release, every fanout task completes independently and its completed-task notification is observed on the parent session.

Regression properties

Property	End-to-end assertion
Task HITL routing	A child approval surfaces on the parent session; its answer reaches the child without a parent model step.
Session-create idempotency	Concurrent and serial /eve/v1/session retries resolve one session identity for one principal, while the same operation id under another principal creates a different session.
Task input-batch ordering	Replaying Q1 after Q2 becomes current cannot clear Q2; the exact Q2 response still resumes the child and completes the task.
Child-task exclusivity	Two same-batch task_send calls to one persistent child produce exactly one working receipt and one AGENT_BUSY result.

Shape

The fanout workers block on approval rather than a timer. The eval records every queued parent turn, proves all ten tasks are nonterminal before interaction, releases them explicitly, then matches updates by task id against the parent stream. Coalesced turns cannot hide updates or the interactive message.

Task completion is polled with task_peek; this fixture has no dependency on the removed task-wait behavior.

Stacked on #1747 (tasks/09). The full fixture passes locally with 27 gates.

[vercel]

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Project	Deployment	Actions	Updated (UTC)
eve-docs	Ready	Preview	Aug 7, 2026 12:11am

1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
eve-docs-4759	Skipped		Aug 7, 2026 12:11am

[github-actions]

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

Key takeaways

• No notable deltas vs tasks/09-background-section-finalization (11528be).

Delta vs tasks/09-background-section-finalization (11528be)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	7.69 MB	7.69 MB	+664 B ⚠️
Package	Unpacked publish size	28.79 MB	28.79 MB	0 B ➖
Package	Installed footprint	72.18 MB	72.18 MB	0 B ➖
Package	Published files	3072	3072	0
Package	Installed files	6780	6780	0
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	17.25 MB	17.25 MB	-40 B ✅
Runtime	Public routes	13	13	0

Changed function payloads vs tasks/09-background-section-finalization (11528be) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/__server.func	changed	8.62 MB	8.62 MB	-20 B ✅	none
functions/.well-known/workflow/v1/flow.func	changed	8.62 MB	8.62 MB	-20 B ✅	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	110.59 MB	110.59 MB	0 B ➖
Installed packages	121	121	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	43.26 MB	43.26 MB	0 B ➖
devDependency package bytes	5.04 MB	5.04 MB	0 B ➖

Build Metadata

• Preset: vercel
• Nitro: nitro@3.0.260610-beta
• Output directory: apps/fixtures/weather-agent/.vercel/output
• Build metadata timestamp: 2026-08-07T00:12:05.019Z
• Route aliases: 13 public, 1 internal (14 total aliases)
• Vercel routes in config: 16
• Severity legend: 🔴 dominant/large, 🟠 notable, 🟡 watch, ⚪ small

Package Drill-Down

Package Details

• Package: eve@0.30.7
• Package directory: packages/eve
• Tarball: 7.69 MB (eve-0.30.7.tgz)
• Unpacked payload: 28.79 MB across 3072 published files
• Installed footprint: 72.18 MB across 6780 installed files
• Installed root package: 27.44 MB
• Installed dependencies: 44.74 MB
• Runtime dependencies: 2
• Peer dependencies: 5 (4 optional)

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

Heavy installed dependencies

• eve: 27.44 MB (38.0%)
• @rolldown/binding-linux-x64-gnu: 19.35 MB (26.8%)
• ai: 6.65 MB (9.2%)
• zod: 5.07 MB (7.0%)
• undici: 3.50 MB (4.9%)

Publish payload breakdown

Published file size
🔴 dist/src/compiled/shadcn-registry/index.js       [################........] 9.68 MB 33.6%
🟠 dist/src/compiled/@photon-ai/chat-adapter-ime... [####....................] 2.42 MB 8.4%
🟠 dist/src/compiled/experimental-ai-sdk-code-mo... [###.....................] 1.51 MB 5.2%
🟡 dist/src/compiled/_chunks/node/undici-DWL_MYm... [#.......................] 502.4 kB 1.7%
🟡 dist/src/compiled/_chunks/workflow/undici-DWL... [#.......................] 502.4 kB 1.7%
🔴 Other published files                            [########################] 14.18 MB 49.2%

Installed footprint breakdown

Installed package size
🔴 eve                             [########################] 27.44 MB 38.0%
🔴 @rolldown/binding-linux-x64-gnu [#################.......] 19.35 MB 26.8%
🔴 ai                              [######..................] 6.65 MB 9.2%
🔴 zod                             [####....................] 5.07 MB 7.0%
🟠 undici                          [###.....................] 3.50 MB 4.9%
🟠 nitro                           [##......................] 2.41 MB 3.3%
🔴 Other installed packages        [#######.................] 7.77 MB 10.8%

Runtime dependencies (2)

Package	Range	Notes
nitro	3.0.260610-beta
undici	8.9.0

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: 110.59 MB across 8656 installed files
• Installed packages: 121 total (115 transitive-only)
• dependencies: 4 direct packages totaling 43.26 MB
• devDependencies: 2 direct packages totaling 5.04 MB
• Other transitive package files: 62.29 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 (25.3%)
• eve: 27.44 MB (24.8%)
• @rolldown/binding-linux-x64-gnu: 19.35 MB (17.5%)
• zod: 9.02 MB (8.2%)
• ai: 6.65 MB (6.0%)

Installed footprint breakdown

Installed package size
🔴 @typescript/typescript-linux-x64 [########################] 27.95 MB 25.3%
🔴 eve                              [########################] 27.44 MB 24.8%
🔴 @rolldown/binding-linux-x64-gnu  [#################.......] 19.35 MB 17.5%
🔴 zod                              [########................] 9.02 MB 8.2%
🔴 ai                               [######..................] 6.65 MB 6.0%
🟠 undici                           [###.....................] 3.50 MB 3.2%
🔴 Other installed packages         [##############..........] 16.68 MB 15.1%

dependencies (4)

Package	Range	Installed size	Share
@vercel/connect	0.4.3	141.0 kB	0.1%
ai	^7.0.38	6.65 MB	6.0%
eve	file:eve-0.30.7.tgz	27.44 MB	24.8%
zod	4.4.3	9.02 MB	8.2%

devDependencies (2)

Package	Range	Installed size	Share
@types/node	24.x	2.54 MB	2.3%
typescript	7.0.2	2.50 MB	2.3%

Function Drill-Down

Payload Size Graph

Unique function payload size and share of total
🔴 functions/.well-known/workflow/v1/flow.func     [########################] 8.62 MB 50.0%
🔴 functions/__server.func                         [########################] 8.62 MB 50.0%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 8.62 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	8.62 MB
Function files	8.62 MB across 44 files
Traced dependencies	0 B
Signal	🟠 Bundled file index.mjs is 2.43 MB (28.2%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [########################] 2.43 MB 28.2%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.63 MB 18.9%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.4%
🟡 _chunks/sandbox.mjs             [########................] 769.0 kB 8.9%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.8 kB 5.0%
🟠 Other bundled files             [#######################.] 2.38 MB 27.6%

🧾 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 • 12 public routes, 1 internal alias • 8.62 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/clear /eve/v1/session/compact /eve/v1/session/reset
Internal aliases	/__server
Runtime	nodejs24.x
Handler	index.mjs
Payload	8.62 MB
Function files	8.62 MB across 44 files
Traced dependencies	0 B
Signal	🟠 Bundled file index.mjs is 2.43 MB (28.2%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [########################] 2.43 MB 28.2%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.63 MB 18.9%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.4%
🟡 _chunks/sandbox.mjs             [########................] 769.0 kB 8.9%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.8 kB 5.0%
🟠 Other bundled files             [#######################.] 2.38 MB 27.6%

🧾 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: 1.88 s -> 1.76 s (-112.1 ms) vs tasks/09-background-section-finalization (11528be).
• Timing is informational: shared GitHub runners are too variable for a hard timing budget.

Detailed phase timings vs `tasks/09-background-section-finalization (11528be)`

Phase	Baseline	Current	Delta
extension.check	8.9 ms	7.2 ms	-1.7 ms
project.resolve	3.3 ms	2.3 ms	-1.0 ms
workspace.create	0.8 ms	0.9 ms	+0.1 ms
host.prepare	237.5 ms	184.6 ms	-52.9 ms
vercel.service-prefix.resolve	1.4 ms	1.4 ms	0.0 ms
nitro.create	180.4 ms	176.9 ms	-3.5 ms
sandbox.prewarm	274.9 ms	314.2 ms	+39.3 ms
nitro.cache.prepare	0.2 ms	0.2 ms	0.0 ms
nitro.prepare	0.6 ms	0.6 ms	0.0 ms
nitro.public-assets	0.6 ms	0.6 ms	0.0 ms
nitro.prerender	0.4 ms	0.4 ms	0.0 ms
nitro.bundle	1.10 s	1.03 s	-75.4 ms
nitro.cache.write	0.2 ms	0.3 ms	+0.1 ms
vercel.workflow-function.materialize	56.9 ms	38.9 ms	-18.0 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	7.4 ms	8.4 ms	+1.0 ms
workspace.remove	1.5 ms	1.6 ms	+0.1 ms

[ruiconti]

Superseded by #1759: same seven evals plus a fix for the world-agnostic exclusivity-race flake seen in this PR's CI. The deterministic e2e-vercel fanout failure is a product bug, tracked in #1759's description.