feat(eve): harden the instrumentation bus and wire providers to it

[chadhietala]

Part of the instrumentation providers stack. Stacks on #1814.

The agent/instrumentation/ directory shipped in #1810 registers providers and
then never hears from them again. This PR makes the bus underneath it something
a provider can actually be trusted to sit on, and connects the two.

Four things, in the order they build on each other.

Action events name what they carry. A subagent dispatch and an ordinary tool
call arrived on the bus as the same tool.call.* event, with the difference
recoverable only by inspecting the tool name. They are now action.* with an
explicit kind (remote-agent-call, subagent-call, tool-call), and
toolName is name, because the field no longer only ever holds a tool's.

Every event carries an idempotencyKey. eve's durable execution means a
provider can observe the same operation twice — the second time in a different
process, after a resume. The key is derived from identity eve reconstructs on
replay rather than generated, so both observations agree, and it is prefixed by
class so a turn id that happens to equal a session id cannot collide into one
row. It replaces the old id, which was a fresh value per observation and
therefore useful to nobody.

A handler that will not settle no longer holds the bus. Dispatch is
sequential and awaited, so one hanging handler stalled every provider behind it
and the agent turn with them. A handler now has a deadline. It cannot be
cancelled, only left running, and that is what makes the terminal the hazard:
handing a completion to a handler that may never have opened the operation is
worse than handing it nothing. So the rest of that operation is withheld from
that provider alone, scoped by idempotencyKey and released when the terminal
passes. The provider keeps receiving every other operation.

Authored providers reach the bus. This was the real gap. Producing an
instrumentation plugin is exactly what told the dev host to skip installing the
local tracing runtime, and nothing else installed one — so with the flag on and
a provider directory present, there was no bus, no OTel bridge, and no
runInContext. installInstrumentationRuntime is now the install both layouts
share, so the flagged path cannot drift into being a second runtime. A directory
that declared no OpenTelemetry still gets a bus: its providers see every event,
they just have no spans to hang them on. flush and shutdown are driven by
eve, the latter from Nitro's close hook — the last point a buffered exporter
can still reach the network.

Not in this PR

Two items from the plan for this step are blocked, and are worth naming rather
than quietly dropping:

• ctx.state needs the provider-state carve-out from step-cancellation
  discard, which lives at the bottom of the stack in refactor(eve): eve-owned instrumentation event payloads #1618 and does not exist
  yet. ProviderContext ships empty so adding it later is additive.
• evaluation on ProviderSetupContext needs run identity eve eval does
  not have — the research doc names this as an open question, and the eval
  runner is a separate process from the agent server it drives. A field that is
  permanently undefined is a public promise with no implementation, so it
  waits.

Scope

Still entirely behind experimental.instrumentationProviders, still off by
default. The single-config layout is untouched.

Validation

pnpm fmt, pnpm lint, pnpm typecheck, pnpm guard:invariants; the full
unit tier (588 files, 6100 tests) and the integration tier over src/internal
and src/harness. New unit coverage for the key derivation, the handler
timeout's three behaviors, and the provider-to-bus wiring. Not run locally:
scenario and e2e.

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
eve-docs	Ready	Preview	Aug 8, 2026 4:11pm
eve-docs-4759	Ready	Preview, v0	Aug 8, 2026 4:11pm

[github-actions]

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

Key takeaways

• No notable deltas vs instr/07-content-redaction (bf943ac).

Delta vs instr/07-content-redaction (bf943ac)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	7.86 MB	7.86 MB	+2.9 kB ⚠️
Package	Unpacked publish size	29.36 MB	29.38 MB	+12.2 kB ⚠️
Package	Installed footprint	72.80 MB	72.81 MB	+12.2 kB ⚠️
Package	Published files	3090	3092	+2
Package	Installed files	6800	6802	+2
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	17.08 MB	17.09 MB	+3.7 kB ⚠️
Runtime	Public routes	13	13	0

Changed function payloads vs instr/07-content-redaction (bf943ac) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/__server.func	changed	8.54 MB	8.54 MB	+1.9 kB ⚠️	none
functions/.well-known/workflow/v1/flow.func	changed	8.54 MB	8.54 MB	+1.9 kB ⚠️	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	111.21 MB	111.22 MB	+12.2 kB ⚠️
Installed packages	121	121	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	43.85 MB	43.86 MB	+12.2 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: 2026-08-08T16:12:54.283Z
• 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: 7.86 MB (eve-0.31.3.tgz)
• Unpacked payload: 29.38 MB across 3092 published files
• Installed footprint: 72.81 MB across 6802 installed files
• Installed root package: 28.02 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: 28.02 MB (38.5%)
• @rolldown/binding-linux-x64-gnu: 19.35 MB (26.6%)
• ai: 6.67 MB (9.2%)
• zod: 5.07 MB (7.0%)
• undici: 3.50 MB (4.8%)

Publish payload breakdown

Published file size
🔴 dist/src/compiled/shadcn-registry/index.js       [################........] 9.68 MB 33.0%
🟠 dist/src/compiled/@photon-ai/chat-adapter-ime... [#####...................] 2.92 MB 10.0%
🟠 dist/src/compiled/experimental-ai-sdk-code-mo... [###.....................] 1.51 MB 5.1%
🟡 dist/src/compiled/@vercel/sandbox/index.js       [#.......................] 638.9 kB 2.2%
🟡 dist/src/compiled/_chunks/workflow/undici-CUI... [#.......................] 508.8 kB 1.7%
🔴 Other published files                            [########################] 14.11 MB 48.0%

Installed footprint breakdown

Installed package size
🔴 eve                             [########################] 28.02 MB 38.5%
🔴 @rolldown/binding-linux-x64-gnu [#################.......] 19.35 MB 26.6%
🔴 ai                              [######..................] 6.67 MB 9.2%
🔴 zod                             [####....................] 5.07 MB 7.0%
🟠 undici                          [###.....................] 3.50 MB 4.8%
🟠 nitro                           [##......................] 2.41 MB 3.3%
🔴 Other installed packages        [#######.................] 7.79 MB 10.7%

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: 111.22 MB across 8678 installed files
• Installed packages: 121 total (115 transitive-only)
• dependencies: 4 direct packages totaling 43.86 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

• eve: 28.02 MB (25.2%)
• @typescript/typescript-linux-x64: 27.95 MB (25.1%)
• @rolldown/binding-linux-x64-gnu: 19.35 MB (17.4%)
• zod: 9.02 MB (8.1%)
• ai: 6.67 MB (6.0%)

Installed footprint breakdown

Installed package size
🔴 eve                              [########################] 28.02 MB 25.2%
🔴 @typescript/typescript-linux-x64 [########################] 27.95 MB 25.1%
🔴 @rolldown/binding-linux-x64-gnu  [#################.......] 19.35 MB 17.4%
🔴 zod                              [########................] 9.02 MB 8.1%
🔴 ai                               [######..................] 6.67 MB 6.0%
🟠 undici                           [###.....................] 3.50 MB 3.2%
🔴 Other installed packages         [##############..........] 16.71 MB 15.0%

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	28.02 MB	25.2%
zod	4.4.3	9.02 MB	8.1%

devDependencies (2)

Package	Range	Installed size	Share
@types/node	24.x	2.54 MB	2.3%
typescript	7.0.2	2.50 MB	2.2%

Function Drill-Down

Payload Size Graph

Unique function payload size and share of total
🔴 functions/.well-known/workflow/v1/flow.func     [########################] 8.54 MB 50.0%
🔴 functions/__server.func                         [########################] 8.54 MB 50.0%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 8.54 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	8.54 MB
Function files	8.54 MB across 44 files
Traced dependencies	0 B
Signal	🟠 Bundled file index.mjs is 2.34 MB (27.4%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [########################] 2.34 MB 27.4%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.63 MB 19.1%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.5%
🟡 _chunks/sandbox.mjs             [########................] 777.1 kB 9.1%
🟡 _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 • 8.54 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	8.54 MB
Function files	8.54 MB across 44 files
Traced dependencies	0 B
Signal	🟠 Bundled file index.mjs is 2.34 MB (27.4%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [########################] 2.34 MB 27.4%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.63 MB 19.1%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.5%
🟡 _chunks/sandbox.mjs             [########................] 777.1 kB 9.1%
🟡 _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: 3.49 s -> 2.90 s (-593.3 ms) vs instr/07-content-redaction (bf943ac).
• Timing is informational: shared GitHub runners are too variable for a hard timing budget.

Detailed phase timings vs `instr/07-content-redaction (bf943ac)`

Phase	Baseline	Current	Delta
extension.check	11.1 ms	12.1 ms	+1.0 ms
project.resolve	6.4 ms	1.5 ms	-4.9 ms
workspace.create	1.2 ms	1.2 ms	0.0 ms
host.prepare	1.36 s	790.7 ms	-572.9 ms
vercel.service-prefix.resolve	2.8 ms	2.3 ms	-0.5 ms
nitro.create	211.4 ms	209.4 ms	-2.0 ms
sandbox.prewarm	524.0 ms	488.1 ms	-35.9 ms
nitro.cache.prepare	0.2 ms	0.3 ms	+0.1 ms
nitro.prepare	0.8 ms	0.9 ms	+0.1 ms
nitro.public-assets	0.7 ms	0.7 ms	0.0 ms
nitro.prerender	0.5 ms	0.5 ms	0.0 ms
nitro.bundle	1.34 s	1.36 s	+21.7 ms
nitro.cache.write	0.3 ms	0.4 ms	+0.1 ms
vercel.workflow-function.materialize	23.1 ms	23.0 ms	-0.1 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	3.5 ms	3.6 ms	+0.1 ms
workspace.remove	2.2 ms	2.1 ms	-0.1 ms