feat(dev): drained transactional dev server on the stock Nitro contract

[ctgowrie]

First PR of the stock-Nitro dev-server stack (followed by #790 → #792 → #798), based on main.

What

Rebuilds the dev server on stock Nitro's stable-parent/disposable-worker architecture, with two guarantees beyond the stock runner manager:

• Drained worker replacement. The parent tracks admitted responses and upgraded sockets per worker. A retired worker terminates only after its last exchange settles, preventing the ECONNRESET class of structural-reload failures. Crashed workers restart, shutdown has a bounded deadline, and a failed upgrade destroys only its socket.
• Transactional authored rebuilds. A candidate is compiled, bundled, and readiness-gated while the previous worker keeps serving. Commit is worker-first, generation-pointer-second. Failures before the swap preserve the old worker and generation; activation failures after the swap keep the live generation-neutral host and retry activation on the next rebuild. Runtime-only edits publish a generation without replacing the worker.

The dev schedule route now resolves the committed runtime generation instead of the removed legacy <app>/.eve/compile location. Schedule lookup and task execution share that one resolved artifact source, so a concurrent rebuild cannot split a dispatch across generations.

Build-publication lock transitions also retain atomic rename semantics while retrying bounded Windows EPERM/EACCES/EBUSY contention.

Tests

• Drain and rebuild scenario coverage for readiness failure, worker crashes, open streams and sockets, failed upgrades, activation failure, environment rollback, and bounded shutdown.
• Focused unit coverage proving schedule lookup and execution use the same active generation.
• The agent-schedules local E2E fixture exercises the dev route through a real rebuild; both configured model jobs pass on this branch.
• Unit, integration, typecheck, lint, docs, and invariant checks.

🤖 Generated with Claude Code

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
eve-docs	Ready	Preview, Comment	Jul 15, 2026 12:05am
eve-docs-1644	Ready	Preview, Comment, Open in v0	Jul 15, 2026 12:05am
eve-docs-4759	Ready	Preview, Comment, Open in v0	Jul 15, 2026 12:05am

[github-actions]

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

Key takeaways

• No notable deltas vs main (58dd402).

Delta vs main (58dd402)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	3.65 MB	3.69 MB	+38.7 kB ⚠️
Package	Unpacked publish size	13.26 MB	13.38 MB	+118.5 kB ⚠️
Package	Installed footprint	52.52 MB	52.64 MB	+118.5 kB ⚠️
Package	Published files	2563	2588	+25
Package	Installed files	5803	5828	+25
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	9.35 MB	9.37 MB	+12.5 kB ⚠️
Runtime	Public routes	9	9	0

Changed function payloads vs main (58dd402) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/.well-known/workflow/v1/flow.func	changed	5.87 MB	5.88 MB	+6.3 kB ⚠️	none
functions/__server.func	changed	3.48 MB	3.49 MB	+6.3 kB ⚠️	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	90.79 MB	90.90 MB	+118.5 kB ⚠️
Installed packages	122	122	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	27.46 MB	27.58 MB	+118.5 kB ⚠️
devDependency package bytes	5.04 MB	5.04 MB	0 B ➖

Build Metadata

• Preset: vercel
• Nitro: [email protected]
• Output directory: apps/fixtures/weather-agent/.vercel/output
• Build metadata timestamp: 2026-07-15T00:06:04.728Z
• Route aliases: 9 public, 1 internal (10 total aliases)
• Vercel routes in config: 10
• Severity legend: 🔴 dominant/large, 🟠 notable, 🟡 watch, ⚪ small

Package Drill-Down

Package Details

• Package: [email protected]
• Package directory: packages/eve
• Tarball: 3.69 MB (eve-0.24.2.tgz)
• Unpacked payload: 13.38 MB across 2588 published files
• Installed footprint: 52.64 MB across 5828 installed files
• Installed root package: 12.10 MB
• Installed dependencies: 40.54 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

• @rolldown/binding-linux-x64-gnu: 19.13 MB (36.3%)
• eve: 12.10 MB (23.0%)
• ai: 6.39 MB (12.1%)
• zod: 5.04 MB (9.6%)
• nitro: 2.41 MB (4.6%)

Publish payload breakdown

Published file size
🟠 dist/src/compiled/experimental-ai-sdk-code-mo... [####....................] 1.51 MB 11.3%
🟡 dist/src/compiled/@vercel/sandbox/index.js       [#.......................] 622.2 kB 4.7%
🟡 dist/src/compiled/_chunks/workflow/undici-fb5... [#.......................] 502.4 kB 3.8%
🟡 dist/src/compiled/@chat-adapter/slack/index.js   [#.......................] 433.8 kB 3.2%
🟡 dist/src/compiled/_chunks/workflow/dist-Blxny... [#.......................] 277.7 kB 2.1%
🔴 Other published files                            [########################] 10.04 MB 75.0%

Installed footprint breakdown

Installed package size
🔴 @rolldown/binding-linux-x64-gnu [########################] 19.13 MB 36.3%
🔴 eve                             [###############.........] 12.10 MB 23.0%
🔴 ai                              [########................] 6.39 MB 12.1%
🔴 zod                             [######..................] 5.04 MB 9.6%
🟠 nitro                           [###.....................] 2.41 MB 4.6%
🟡 @ai-sdk/provider-utils          [#.......................] 847.4 kB 1.6%
🔴 Other installed packages        [########................] 6.73 MB 12.8%

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: 90.90 MB across 7646 installed files
• Installed packages: 122 total (116 transitive-only)
• dependencies: 4 direct packages totaling 27.58 MB
• devDependencies: 2 direct packages totaling 5.04 MB
• Other transitive package files: 58.28 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 (30.7%)
• @rolldown/binding-linux-x64-gnu: 19.13 MB (21.0%)
• eve: 12.10 MB (13.3%)
• zod: 9.00 MB (9.9%)
• ai: 6.39 MB (7.0%)

Installed footprint breakdown

Installed package size
🔴 @typescript/typescript-linux-x64 [########################] 27.95 MB 30.7%
🔴 @rolldown/binding-linux-x64-gnu  [################........] 19.13 MB 21.0%
🔴 eve                              [##########..............] 12.10 MB 13.3%
🔴 zod                              [########................] 9.00 MB 9.9%
🔴 ai                               [#####...................] 6.39 MB 7.0%
🟠 @types/node                      [##......................] 2.54 MB 2.8%
🔴 Other installed packages         [############............] 13.80 MB 15.2%

dependencies (4)

Package	Range	Installed size	Share
@vercel/connect	0.2.2	98.6 kB	0.1%
ai	^7.0.26	6.39 MB	7.0%
eve	file:eve-0.24.2.tgz	12.10 MB	13.3%
zod	4.4.3	9.00 MB	9.9%

devDependencies (2)

Package	Range	Installed size	Share
@types/node	24.x	2.54 MB	2.8%
typescript	7.0.2	2.50 MB	2.7%

Function Drill-Down

Payload Size Graph

Unique function payload size and share of total
🔴 functions/.well-known/workflow/v1/flow.func     [########################] 5.88 MB 62.7%
🟠 functions/__server.func                         [##############..........] 3.49 MB 37.3%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 5.88 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	5.88 MB
Function files	5.88 MB across 36 files
Traced dependencies	0 B
Signal	🟠 Bundled file __eve_nitro_handler__.mjs is 2.18 MB (37.1%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 __eve_nitro_handler__.mjs       [########################] 2.18 MB 37.1%
🟡 _chunks/world-vercel.mjs        [#########...............] 826.4 kB 14.1%
🟡 _chunks/sandbox.mjs             [########................] 754.9 kB 12.8%
🟡 _libs/@ai-sdk/gateway+[...].mjs [#####...................] 430.4 kB 7.3%
🟡 _chunks/dist-Blxnyb7-.mjs       [####....................] 349.1 kB 5.9%
🟠 Other bundled files             [###############.........] 1.33 MB 22.7%

🧾 Vercel Config

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

---

🟠 functions/__server.func • 8 public routes, 1 internal alias • 3.49 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]/stream
Internal aliases	/__server
Runtime	nodejs24.x
Handler	index.mjs
Payload	3.49 MB
Function files	3.49 MB across 26 files
Traced dependencies	0 B
Signal	🟠 Bundled file _chunks/runtime-artifacts.mjs is 942.0 kB (27.0%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 _chunks/runtime-artifacts.mjs [########################] 942.0 kB 27.0%
🟠 _chunks/world-vercel.mjs      [#####################...] 826.4 kB 23.7%
🟠 _chunks/sandbox.mjs           [###################.....] 754.9 kB 21.6%
🟡 _chunks/dist-Blxnyb7-.mjs     [#########...............] 348.1 kB 10.0%
⚪ _libs/zod.mjs                 [###.....................] 114.2 kB 3.3%
🟡 Other bundled files           [#############...........] 503.0 kB 14.4%

🧾 Vercel Config

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