refactor(eve): flat lifecycle event names

[chadhietala]

Second in the instrumentation-provider stack, on top of #1618.

Why

Providers subscribed through paired before/after hooks keyed by a boundary name, so a handler's event type was not visible from the key it registered under, and InstrumentationHooks carried two methods where one event only ever needs one.

The events for one model attempt were also named attempt.* while the span they produce is agent.step — a handler and the span it writes disagreed on the noun. Both are the same concern: settling the event names before the bus becomes a public provider contract, so that surface never ships a name we already intend to change.

Approach

Providers subscribe under the event's own type:

readonly events?: {
  readonly "step.started"?: InstrumentationEventHandler<InstrumentationStepStartedLifecycleEvent>;
  readonly "model.call.completed"?: InstrumentationEventHandler<InstrumentationModelCallCompletedEvent>;
  // …
};

and InstrumentationHooks collapses to one publish.

attempt.started / attempt.completed / attempt.failed / attempt.metadata become step.*. InstrumentationAttemptScope deliberately keeps its name — it identifies one attempt of a step, which is exactly what agent.step.attempt records. The started payload takes a …LifecycleEvent suffix because InstrumentationStepStartedEventInput already exists on the public surface for the unrelated step.started runtime-context hook; that collision resolves when the proposal deletes that hook.

Dropping the paired hooks removed the framework-held state a provider used to receive, so the OTel provider now keeps its own modelSpans / toolSpans maps. That is safe because eve balances every start with exactly one terminal: failOpenOperations terminalizes open operations on abort and error, and a retry gets a fresh attemptId.

Also here

tracing/agent-trace-state.ts is extracted. The provider crossed the 700-line cap, and agent-trace-context-store.ts was importing this state from the provider, which had the dependency backwards.

Scope

Publishes nothing — these events are all internal.

Verification

• pnpm fmt, pnpm lint, pnpm guard:invariants
• pnpm --filter eve typecheck
• pnpm test:unit — 5,894 passed
• pnpm test:integration — 575 passed

[vercel]

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Project	Deployment	Actions	Updated (UTC)
eve-docs	Ready	Preview	Aug 8, 2026 1:15pm
eve-docs-4759	Ready	Preview, v0	Aug 8, 2026 1:15pm

[github-actions]

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

Key takeaways

• No notable deltas vs instr/01-owned-payloads (59f53eb).

Delta vs instr/01-owned-payloads (59f53eb)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	7.69 MB	7.69 MB	+329 B ⚠️
Package	Unpacked publish size	28.80 MB	28.80 MB	+561 B ⚠️
Package	Installed footprint	72.23 MB	72.23 MB	+561 B ⚠️
Package	Published files	3063	3063	0
Package	Installed files	6773	6773	0
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	17.06 MB	17.06 MB	-126 B ✅
Runtime	Public routes	13	13	0

Changed function payloads vs instr/01-owned-payloads (59f53eb) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/__server.func	changed	8.53 MB	8.53 MB	-63 B ✅	none
functions/.well-known/workflow/v1/flow.func	changed	8.53 MB	8.53 MB	-63 B ✅	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	110.64 MB	110.64 MB	+561 B ⚠️
Installed packages	121	121	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	43.28 MB	43.28 MB	+561 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: 2026-08-08T13:17:51.491Z
• 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@0.31.3
• Package directory: packages/eve
• Tarball: 7.69 MB (eve-0.31.3.tgz)
• Unpacked payload: 28.80 MB across 3063 published files
• Installed footprint: 72.23 MB across 6773 installed files
• Installed root package: 27.44 MB
• Installed dependencies: 44.79 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: 6.67 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/workflow/undici-CUI... [#.......................] 508.8 kB 1.8%
🟡 dist/src/compiled/_chunks/node/undici-DWL_MYm... [#.......................] 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                              [######..................] 6.67 MB 9.2%
🔴 zod                             [####....................] 5.07 MB 7.0%
🟠 undici                          [###.....................] 3.50 MB 4.9%
🟠 nitro                           [##......................] 2.41 MB 3.3%
🔴 Other installed packages        [#######.................] 7.79 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: 110.64 MB across 8649 installed files
• Installed packages: 121 total (115 transitive-only)
• dependencies: 4 direct packages totaling 43.28 MB
• devDependencies: 2 direct packages totaling 5.04 MB
• Other transitive package files: 62.32 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: 6.67 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                               [######..................] 6.67 MB 6.0%
🟠 undici                           [###.....................] 3.50 MB 3.2%
🔴 Other installed packages         [##############..........] 16.71 MB 15.1%

dependencies (4)

Package	Range	Installed size	Share
@vercel/connect	0.4.3	141.0 kB	0.1%
ai	^7.0.38	6.67 MB	6.0%
eve	file:eve-0.31.3.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     [########################] 8.53 MB 50.0%
🔴 functions/__server.func                         [########################] 8.53 MB 50.0%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 8.53 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	8.53 MB
Function files	8.53 MB across 44 files
Traced dependencies	0 B
Signal	🟠 Bundled file index.mjs is 2.33 MB (27.4%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [#######################.] 2.33 MB 27.4%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.63 MB 19.1%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.5%
🟡 _chunks/sandbox.mjs             [########................] 769.0 kB 9.0%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.8 kB 5.1%
🟠 Other bundled files             [########################] 2.38 MB 27.9%

🧾 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 • 8.53 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]/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	8.53 MB
Function files	8.53 MB across 44 files
Traced dependencies	0 B
Signal	🟠 Bundled file index.mjs is 2.33 MB (27.4%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [#######################.] 2.33 MB 27.4%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.63 MB 19.1%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.5%
🟡 _chunks/sandbox.mjs             [########................] 769.0 kB 9.0%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.8 kB 5.1%
🟠 Other bundled files             [########################] 2.38 MB 27.9%

🧾 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: 2.21 s -> 2.03 s (-184.6 ms) vs instr/01-owned-payloads (59f53eb).
• Timing is informational: shared GitHub runners are too variable for a hard timing budget.

Detailed phase timings vs `instr/01-owned-payloads (59f53eb)`

Phase	Baseline	Current	Delta
extension.check	6.3 ms	1.1 ms	-5.2 ms
project.resolve	3.4 ms	0.6 ms	-2.8 ms
workspace.create	1.1 ms	0.7 ms	-0.4 ms
host.prepare	413.2 ms	177.9 ms	-235.3 ms
vercel.service-prefix.resolve	2.4 ms	2.5 ms	+0.1 ms
nitro.create	209.2 ms	235.7 ms	+26.5 ms
sandbox.prewarm	186.1 ms	186.1 ms	0.0 ms
nitro.cache.prepare	0.3 ms	0.2 ms	-0.1 ms
nitro.prepare	0.9 ms	0.8 ms	-0.1 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	1.36 s	1.39 s	+32.5 ms
nitro.cache.write	0.4 ms	0.4 ms	0.0 ms
vercel.workflow-function.materialize	23.3 ms	23.2 ms	-0.1 ms
agent-summary.emit	0.5 ms	0.4 ms	-0.1 ms
nitro.close	0.1 ms	0.1 ms	0.0 ms
output.publish	3.4 ms	3.5 ms	+0.1 ms
workspace.remove	2.1 ms	2.4 ms	+0.3 ms