feat(eve): publish canonical harness lifecycle events

[chadhietala]

Summary

Phase 4 of local observability, stacked on #1192.

This PR connects eve-native durable transitions to the provider-neutral lifecycle hooks:

• Wraps the existing event handler and publishes only after durable acceptance
• Maps the current early step.started boundary to internal step.preparing
• Keeps AI SDK onStepStart as the complete lifecycle step.started
• Publishes session and turn starts/terminals
• Publishes canonical step completion after action results
• Publishes a terminal for each failed retry/recovery attempt
• Resolves step terminals to their exact attempt scope

Scope

This PR does not register providers, enable local tracing, persist spans, call registerOTel(), or change production behavior without explicitly injected instrumentationHooks.

When hooks are absent, the original event handler is returned unchanged. Hooks without a durable handler do not make emit truthy or switch the harness from generate to stream.

Testing

• Durable handler runs before lifecycle publication
• Early step boundary maps to step.preparing
• Step terminal resolves the active attempt scope
• No-handler execution mode remains unchanged
• Recovery attempts receive distinct terminal identities
• Agent provider spans close through canonical events
• Package typecheck, build, lint, formatting, invariants, and targeted unit tests

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
eve-docs	Ready	Preview, Comment, Open in v0	Jul 24, 2026 8:54pm

[github-actions]

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

Key takeaways

• No notable deltas vs chad/trace-agent-otel-provider (85748e7).

Delta vs chad/trace-agent-otel-provider (85748e7)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	4.05 MB	4.05 MB	+972 B ⚠️
Package	Unpacked publish size	14.74 MB	14.74 MB	+3.4 kB ⚠️
Package	Installed footprint	53.90 MB	53.90 MB	+3.4 kB ⚠️
Package	Published files	2753	2755	+2
Package	Installed files	5993	5995	+2
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	11.67 MB	11.68 MB	+2.8 kB ⚠️
Runtime	Public routes	11	11	0

Changed function payloads vs chad/trace-agent-otel-provider (85748e7) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/.well-known/workflow/v1/flow.func	changed	7.27 MB	7.27 MB	+2.9 kB ⚠️	none
functions/__server.func	changed	4.41 MB	4.41 MB	-20 B ✅	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	92.30 MB	92.30 MB	+3.4 kB ⚠️
Installed packages	122	122	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	29.02 MB	29.03 MB	+3.4 kB ⚠️
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: 2026-07-24T20:55:12.975Z
• Route aliases: 11 public, 1 internal (12 total aliases)
• Vercel routes in config: 12
• Severity legend: 🔴 dominant/large, 🟠 notable, 🟡 watch, ⚪ small

Package Drill-Down

Package Details

• Package: eve@0.27.3
• Package directory: packages/eve
• Tarball: 4.05 MB (eve-0.27.3.tgz)
• Unpacked payload: 14.74 MB across 2755 published files
• Installed footprint: 53.90 MB across 5995 installed files
• Installed root package: 13.46 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

• @rolldown/binding-linux-x64-gnu: 18.96 MB (35.2%)
• eve: 13.46 MB (25.0%)
• ai: 6.43 MB (11.9%)
• zod: 5.04 MB (9.3%)
• nitro: 2.41 MB (4.5%)

Publish payload breakdown

Published file size
🟠 dist/src/compiled/experimental-ai-sdk-code-mo... [###.....................] 1.51 MB 10.2%
🟡 dist/src/compiled/@vercel/sandbox/index.js       [#.......................] 632.4 kB 4.3%
🟡 dist/src/compiled/_chunks/workflow/undici-C2Z... [#.......................] 502.4 kB 3.4%
🟡 dist/src/compiled/@chat-adapter/slack/index.js   [#.......................] 440.5 kB 3.0%
🟡 dist/src/compiled/@vercel/oidc/index.js          [#.......................] 379.5 kB 2.6%
🔴 Other published files                            [########################] 11.28 MB 76.5%

Installed footprint breakdown

Installed package size
🔴 @rolldown/binding-linux-x64-gnu [########################] 18.96 MB 35.2%
🔴 eve                             [#################.......] 13.46 MB 25.0%
🔴 ai                              [########................] 6.43 MB 11.9%
🔴 zod                             [######..................] 5.04 MB 9.3%
🟠 nitro                           [###.....................] 2.41 MB 4.5%
🟡 @ai-sdk/provider-utils          [#.......................] 852.0 kB 1.6%
🔴 Other installed packages        [#########...............] 6.75 MB 12.5%

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: 92.30 MB across 7863 installed files
• Installed packages: 122 total (116 transitive-only)
• dependencies: 4 direct packages totaling 29.03 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 (30.3%)
• @rolldown/binding-linux-x64-gnu: 18.96 MB (20.5%)
• eve: 13.46 MB (14.6%)
• zod: 9.00 MB (9.7%)
• ai: 6.43 MB (7.0%)

Installed footprint breakdown

Installed package size
🔴 @typescript/typescript-linux-x64 [########################] 27.95 MB 30.3%
🔴 @rolldown/binding-linux-x64-gnu  [################........] 18.96 MB 20.5%
🔴 eve                              [############............] 13.46 MB 14.6%
🔴 zod                              [########................] 9.00 MB 9.7%
🔴 ai                               [######..................] 6.43 MB 7.0%
🟠 @types/node                      [##......................] 2.54 MB 2.8%
🔴 Other installed packages         [############............] 13.97 MB 15.1%

dependencies (4)

Package	Range	Installed size	Share
@vercel/connect	0.4.2	135.8 kB	0.1%
ai	^7.0.34	6.43 MB	7.0%
eve	file:eve-0.27.3.tgz	13.46 MB	14.6%
zod	4.4.3	9.00 MB	9.7%

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     [########################] 7.27 MB 62.3%
🟠 functions/__server.func                         [###############.........] 4.41 MB 37.7%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 7.27 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	7.27 MB
Function files	7.27 MB across 39 files
Traced dependencies	0 B
Signal	🟠 Bundled file __eve_nitro_handler__.mjs is 2.71 MB (37.3%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 __eve_nitro_handler__.mjs       [########################] 2.71 MB 37.3%
🟡 _chunks/world-vercel.mjs        [########................] 903.2 kB 12.4%
🟡 _chunks/sandbox.mjs             [#######.................] 767.6 kB 10.6%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.5 kB 5.9%
🟡 _chunks/token-util-B6qBs3-0.mjs [###.....................] 379.1 kB 5.2%
🟠 Other bundled files             [##################......] 2.08 MB 28.5%

🧾 Vercel Config

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

---

🟠 functions/__server.func • 10 public routes, 1 internal alias • 4.41 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	4.41 MB
Function files	4.41 MB across 30 files
Traced dependencies	0 B
Signal	🟠 Bundled file _chunks/runtime-artifacts.mjs is 1.41 MB (32.0%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 _chunks/runtime-artifacts.mjs   [########################] 1.41 MB 32.0%
🟠 _chunks/world-vercel.mjs        [###############.........] 900.3 kB 20.4%
🟠 _chunks/sandbox.mjs             [#############...........] 767.6 kB 17.4%
🟡 _chunks/token-util-B6qBs3-0.mjs [######..................] 379.1 kB 8.6%
🟡 _chunks/dist-BX517Nmz.mjs       [######..................] 348.7 kB 7.9%
🟡 Other bundled files             [##########..............] 599.1 kB 13.6%

🧾 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: 2.49 s -> 2.40 s (-90.6 ms) vs chad/trace-agent-otel-provider (85748e7).
• Timing is informational: shared GitHub runners are too variable for a hard timing budget.

Detailed phase timings vs `chad/trace-agent-otel-provider (85748e7)`

Phase	Baseline	Current	Delta
extension.check	4.7 ms	1.0 ms	-3.7 ms
project.resolve	2.0 ms	0.6 ms	-1.4 ms
workspace.create	1.2 ms	0.8 ms	-0.4 ms
host.prepare	187.3 ms	147.0 ms	-40.3 ms
vercel.service-prefix.resolve	2.4 ms	2.6 ms	+0.2 ms
nitro.app.create	24.2 ms	24.2 ms	0.0 ms
nitro.app.cache.prepare	0.3 ms	0.3 ms	0.0 ms
nitro.app.prepare	1.0 ms	1.0 ms	0.0 ms
nitro.app.public-assets	0.7 ms	0.7 ms	0.0 ms
nitro.app.prerender	0.5 ms	0.4 ms	-0.1 ms
nitro.app.bundle	657.2 ms	682.9 ms	+25.7 ms
nitro.app.cache.write	0.3 ms	0.4 ms	+0.1 ms
sandbox.prewarm	184.9 ms	170.0 ms	-14.9 ms
nitro.flow.create	191.6 ms	156.6 ms	-35.0 ms
nitro.flow.cache.prepare	0.2 ms	0.2 ms	0.0 ms
nitro.flow.prepare	0.9 ms	0.9 ms	0.0 ms
nitro.flow.public-assets	0.1 ms	0.2 ms	+0.1 ms
nitro.flow.prerender	0.0 ms	0.0 ms	0.0 ms
nitro.flow.bundle	1.06 s	1.04 s	-18.2 ms
nitro.flow.cache.write	0.5 ms	0.4 ms	-0.1 ms
nitro.flow.close	0.2 ms	0.2 ms	0.0 ms
workflow.emit	162.4 ms	159.9 ms	-2.5 ms
agent-summary.emit	0.5 ms	0.5 ms	0.0 ms
nitro.app.close	0.1 ms	0.0 ms	-0.1 ms
output.publish	3.7 ms	3.5 ms	-0.2 ms
workspace.remove	5.1 ms	5.3 ms	+0.2 ms

[vercel]

The step.failed lifecycle event is published unconditionally in runSingleModelCall's catch (guarded only by attemptScope !== undefined), producing duplicate/spurious step.failed events whenever a durable emit handler is present.