feat(eve): keep local tracing on with authored instrumentation by chadhietala · Pull Request #1306 · vercel/eve

chadhietala · 2026-07-29T00:29:34Z

Local dev tracing was gated on the absence of agent/instrumentation.ts. Adding an exporter for Honeycomb or Datadog cost you .eve/traces/v1, eve trace ls, and eve trace <id> — the whole local inspection loop.

This makes the two coexist in eve dev.

What changed

eve adopts the authored provider instead of competing with it. The global that trace.setGlobalTracerProvider registers is a ProxyTracerProvider, so eve swaps its delegate for one that observes every tracer it hands out. The authored exporter keeps receiving everything it received before, and additionally sees eve's agent.* spans, which it never got. eve spools the same spans to .eve/traces/v1.

When no provider is registered — no authored file, or an authored setup() that registers nothing — eve falls through to registerOTel exactly as today.

The proxy is matched structurally rather than with instanceof: authored instrumentation.ts resolves @opentelemetry/api from the agent's own dependencies while eve uses its vendored copy, so the two hold different classes. Only the globalThis registry is shared.

harness/adopt-global-tracer-provider.ts (new) — wraps the delegate's tracers and spans; startActiveSpan is reimplemented over startSpan so span creation is always interceptable, and the shadowed span.end is idempotent and runs the real end first so the author's own processors see a finished span.
create-application-nitro.ts — the dev gate is gone. The local plugin is unshifted when there is no authored plugin (today's ordering, unchanged) and pushed after it when there is, so a provider exists to adopt.
local-instrumentation-runtime.ts — adoptGlobalTracerProvider(processor) or else registerOTel. A failed registration probe now warns and installs nothing instead of throwing: a dev-only convenience should not take down a dev server whose authored instrumentation is otherwise fine.
@opentelemetry/api.d.ts — the vendored declaration widens by the minimum: TracerProvider, ProxyTracerProvider, trace.getTracerProvider(), Span.isRecording?(), end(endTime?).

tool-loop.ts already composed integrations: [bridgeIntegration, createOtelIntegration()] for the both-present case, so the turn-time path needed no change. AgentTraceSpanProcessor is duck-typed and already filters the workflow instrumentation scope, so local traces stay free of Workflow spans even though the adopted provider may carry auto-instrumentation.

Scope

eve dev only. Production is untouched, and the authored public API (defineInstrumentation, setup() calling registerOTel) does not change. EVE_TRACES=off remains the opt-out.

Tests

Unit adopt-global-tracer-provider.test.ts — spans reach onStart/onEnd; the inner end runs exactly once and before onEnd; sampled-out spans are skipped; startActiveSpan returns the callback's value; one tracer per name@version; a non-proxy global declines.
Scenario local-instrumentation-runtime-conflict.scenario.test.ts — inverted from asserting the throw. Registers via the agent's own @vercel/otel first, then asserts the authored processor still receives agent.session and eve writes a segment under .eve/traces/v1/<traceId>.
Scenario create-application-nitro.scenario.test.ts — dev plugin ordering: the local plugin follows the authored one when present.

`eve dev` gated its zero-config trace writer on the absence of `agent/instrumentation.ts`, so adding an exporter for Honeycomb or Datadog cost you `.eve/traces/v1` and the whole `eve trace` loop. eve now adopts the authored provider instead of competing with it. The global registered by `setGlobalTracerProvider` is a `ProxyTracerProvider`, so eve swaps its delegate for one that observes every tracer it hands out. The authored exporter keeps receiving everything it did before and additionally sees eve's `agent.*` spans; eve spools the same spans to disk. When nothing is registered, eve registers its own provider exactly as before. The dev plugin is ordered after the authored instrumentation plugin so a provider exists to adopt, and a failed registration probe now warns and installs nothing rather than throwing — a development convenience must not take down a dev server whose instrumentation is otherwise fine. Production is untouched. Signed-off-by: Chad Hietala <chadhietala@gmail.com>

vercel · 2026-07-29T00:29:40Z

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Project	Deployment	Actions	Updated (UTC)
eve-docs	Ready	Preview, Comment, Open in v0	Jul 29, 2026 1:40am
eve-docs-4759	Ready	Preview, Comment, Open in v0	Jul 29, 2026 1:40am

github-actions · 2026-07-29T00:33:05Z

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

Key takeaways

No notable deltas vs main (c27b44a).

Delta vs `main (c27b44a)`

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	7.59 MB	7.61 MB	+16.1 kB ⚠️
Package	Unpacked publish size	28.70 MB	28.75 MB	+52.3 kB ⚠️
Package	Installed footprint	69.82 MB	69.88 MB	+52.3 kB ⚠️
Package	Published files	2854	2863	+9
Package	Installed files	6327	6336	+9
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	16.70 MB	16.72 MB	+26.6 kB ⚠️
Runtime	Public routes	11	11	0

Changed function payloads vs main (c27b44a) (2)

Function	Status	Baseline	Current	Delta	Route changes
`functions/__server.func`	changed	8.35 MB	8.36 MB	+13.3 kB ⚠️	none
`functions/.well-known/workflow/v1/flow.func`	changed	8.35 MB	8.36 MB	+13.3 kB ⚠️	none

`eve init` install

Metric	Baseline	Current	Delta
Installed footprint	108.23 MB	108.28 MB	+52.3 kB ⚠️
Installed packages	123	123	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	43.02 MB	43.07 MB	+52.2 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: 2026-07-29T01:41:10.886Z
Route aliases: 11 public, 1 internal (12 total aliases)
Vercel routes in config: 14
Severity legend: 🔴 dominant/large, 🟠 notable, 🟡 watch, ⚪ small

Package Drill-Down

Package Details

Package: eve@0.27.11
Package directory: packages/eve
Tarball: 7.61 MB (eve-0.27.11.tgz)
Unpacked payload: 28.75 MB across 2863 published files
Installed footprint: 69.88 MB across 6336 installed files
Installed root package: 27.39 MB
Installed dependencies: 42.48 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: 27.39 MB (39.2%)
@rolldown/binding-linux-x64-gnu: 18.96 MB (27.1%)
ai: 6.52 MB (9.3%)
zod: 5.07 MB (7.3%)
nitro: 2.41 MB (3.4%)

Publish payload breakdown

Published file size
🔴 dist/src/compiled/shadcn-registry/index.js       [########################] 13.15 MB 45.7%
🟠 dist/src/compiled/experimental-ai-sdk-code-mo... [###.....................] 1.51 MB 5.2%
🟡 dist/src/compiled/@vercel/sandbox/index.js       [#.......................] 632.5 kB 2.2%
🟡 dist/src/compiled/_chunks/workflow/undici-DWL... [#.......................] 502.4 kB 1.7%
🟡 dist/src/compiled/@chat-adapter/slack/index.js   [#.......................] 440.5 kB 1.5%
🔴 Other published files                            [#######################.] 12.52 MB 43.5%

Installed footprint breakdown

Installed package size
🔴 eve                             [########################] 27.39 MB 39.2%
🔴 @rolldown/binding-linux-x64-gnu [#################.......] 18.96 MB 27.1%
🔴 ai                              [######..................] 6.52 MB 9.3%
🔴 zod                             [####....................] 5.07 MB 7.3%
🟠 nitro                           [##......................] 2.41 MB 3.4%
🟠 undici                          [##......................] 1.86 MB 2.7%
🔴 Other installed packages        [#######.................] 7.67 MB 11.0%

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: 108.28 MB across 8204 installed files
Installed packages: 123 total (117 transitive-only)
dependencies: 4 direct packages totaling 43.07 MB
devDependencies: 2 direct packages totaling 5.04 MB
Other transitive package files: 60.17 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 (25.8%)
eve: 27.39 MB (25.3%)
@rolldown/binding-linux-x64-gnu: 18.96 MB (17.5%)
zod: 9.02 MB (8.3%)
ai: 6.52 MB (6.0%)

Installed footprint breakdown

Installed package size
🔴 @typescript/typescript-linux-x64 [########################] 27.95 MB 25.8%
🔴 eve                              [########################] 27.39 MB 25.3%
🔴 @rolldown/binding-linux-x64-gnu  [################........] 18.96 MB 17.5%
🔴 zod                              [########................] 9.02 MB 8.3%
🔴 ai                               [######..................] 6.52 MB 6.0%
🟠 @types/node                      [##......................] 2.54 MB 2.3%
🔴 Other installed packages         [##############..........] 15.90 MB 14.7%

dependencies (4)

Package	Range	Installed size	Share
`@vercel/connect`	`0.4.2`	135.8 kB	0.1%
`ai`	`^7.0.38`	6.52 MB	6.0%
`eve`	`file:eve-0.27.11.tgz`	27.39 MB	25.3%
`zod`	`4.4.3`	9.02 MB	8.3%

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     [########################] 8.36 MB 50.0%
🔴 functions/__server.func                         [########################] 8.36 MB 50.0%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 8.36 MB

Metric	Value
Public routes	`/.well-known/workflow/v1/flow`
Runtime	`nodejs24.x`
Handler	`index.mjs`
Payload	8.36 MB
Function files	8.36 MB across 44 files
Traced dependencies	0 B
Signal	🟠 Bundled file `index.mjs` is 2.26 MB (27.1%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [#######################.] 2.26 MB 27.1%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.59 MB 19.0%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.7%
🟡 _chunks/sandbox.mjs             [########................] 768.8 kB 9.2%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.8 kB 5.2%
🟠 Other bundled files             [########################] 2.33 MB 27.8%

🧾 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 • 10 public routes, 1 internal alias • 8.36 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	8.36 MB
Function files	8.36 MB across 44 files
Traced dependencies	0 B
Signal	🟠 Bundled file `index.mjs` is 2.26 MB (27.1%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [#######################.] 2.26 MB 27.1%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.59 MB 19.0%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.7%
🟡 _chunks/sandbox.mjs             [########................] 768.8 kB 9.2%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.8 kB 5.2%
🟠 Other bundled files             [########################] 2.32 MB 27.8%

🧾 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: 1.95 s -> 1.79 s (-158.0 ms) vs main (c27b44a).
Timing is informational: shared GitHub runners are too variable for a hard timing budget.

Detailed phase timings vs `main (c27b44a)`

Phase	Baseline	Current	Delta
`extension.check`	1.1 ms	11.1 ms	+10.0 ms
`project.resolve`	0.6 ms	1.0 ms	+0.4 ms
`workspace.create`	0.7 ms	5.2 ms	+4.5 ms
`host.prepare`	282.2 ms	173.9 ms	-108.3 ms
`vercel.service-prefix.resolve`	2.0 ms	1.7 ms	-0.3 ms
`nitro.create`	203.1 ms	177.5 ms	-25.6 ms
`sandbox.prewarm`	172.5 ms	183.0 ms	+10.5 ms
`nitro.cache.prepare`	0.3 ms	0.3 ms	0.0 ms
`nitro.prepare`	0.8 ms	0.8 ms	0.0 ms
`nitro.public-assets`	0.7 ms	0.7 ms	0.0 ms
`nitro.prerender`	0.5 ms	0.6 ms	+0.1 ms
`nitro.bundle`	1.25 s	1.20 s	-49.8 ms
`nitro.cache.write`	0.4 ms	0.3 ms	-0.1 ms
`vercel.workflow-function.materialize`	21.4 ms	22.1 ms	+0.7 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`	3.3 ms	3.3 ms	0.0 ms
`workspace.remove`	2.0 ms	2.0 ms	0.0 ms

`trace.getTracerProvider()` returns a `ProxyTracerProvider` whether or not anyone registered one: with nothing registered the API hands back its own standby proxy rather than a no-op. The duck-typed check saw `setDelegate` on that standby, wrapped the no-op delegate, and skipped `registerOTel` — so on the zero-config path, which is the common one, no processor was ever attached and no context manager registered. Every `eve dev` run without an authored `instrumentation.ts` logged "eve could not observe OpenTelemetry spans" and wrote nothing. Compare delegates instead. A fresh proxy's delegate is the shared no-op singleton, so a delegate that differs from it is the one an author registered. The unit test for the no-provider case passed over a fake that had no `getDelegate` at all, which is not what an unclaimed process looks like. It now also covers a real `ProxyTracerProvider` with no delegate set. Signed-off-by: Chad Hietala <chadhietala@gmail.com>

Review of the always-on local tracing change surfaced five defects. Adoption swapped a proxy's delegate after authored `setup()` had run, which is too late: `ProxyTracerProvider.getTracer` hands out the delegate's concrete tracer once a delegate exists, so any tracer the authored setup created — an auto-instrumentation's, say — kept a direct reference eve could never reach. eve now claims the global `@opentelemetry/api` registry slot from a plugin that runs *before* authored instrumentation, so every tracer the author's provider hands out is observed from the start. It does not create the registry object: that object carries the version of whichever API instance registers first and `registerGlobal` refuses a mismatched write, so eve decorates the author's own object when it arrives. Adoption stays as the fallback for a slot eve cannot claim. Also fixed: - Startup no longer depends on the authored sampler. The old probe started a real span and required its processor to see it, so an `always_off` or ratio sampler made `eve dev` boot probabilistically. eve now checks only for a context manager, using a span the API owns outright. - Spans are observed through a `Proxy` rather than by assigning over `span.end`, which threw on a frozen or accessor-backed span. A span whose `end` cannot be substituted at all is declined rather than crashed on. - `setup` may be `async` and is awaited before anything else looks for a tracer provider. It typechecked as `async` before but its promise was dropped, letting eve's own setup win the race and starve the authored exporter. - Observed tracers are no longer cached on an interpolated `name@version` key, which ignored `options.schemaUrl` and could collide. Signed-off-by: Chad Hietala <chadhietala@gmail.com>

vercel Bot deployed to Preview – eve-docs-4759 July 29, 2026 00:30 View deployment

vercel Bot deployed to Preview – eve-docs July 29, 2026 00:31 View deployment

chadhietala marked this pull request as draft July 29, 2026 00:31

De-ASI-INTERFACE approved these changes Jul 29, 2026

View reviewed changes

vercel Bot deployed to Preview – eve-docs-4759 July 29, 2026 00:51 View deployment

vercel Bot deployed to Preview – eve-docs July 29, 2026 00:52 View deployment

vercel Bot deployed to Preview – eve-docs-4759 July 29, 2026 01:40 View deployment

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feat(eve): keep local tracing on with authored instrumentation - #1306

feat(eve): keep local tracing on with authored instrumentation#1306
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chadhietala commented Jul 29, 2026

What changed

Scope

Tests

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

Delta vs main (c27b44a)

eve init install

Package Details

eve init install details

Payload Size Graph

Top Function Payloads

Build Timing: e2e/fixtures/agent-tools-sandbox

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

Delta vs `main (c27b44a)`

`eve init` install

`eve init` install details

Build Timing: `e2e/fixtures/agent-tools-sandbox`