feat(eve): subagent sessions inherit the parent's remaining token quota

[ruiconti]

Delegated subagent sessions got a fixed 5M input-token cap no matter what the delegating parent had left to spend, and a completed child's spend never counted against the parent's quota. Both halves were wrong in opposite directions: a parent near its limit could grant a child 5M it didn't have, and a parent nowhere near its limit could fan out children whose combined spend was unbounded by the root's configured budget. #488 surfaced child usage to callers; this PR closes the loop and makes the session quota coherent across a delegation tree.

What

• Subagent dispatch computes the parent's remaining quota (configured limit minus accumulated session usage, per axis) and grants each child in the batch an even share of it: floor(remaining / delegationFanOut), where the fan-out counts the batch's local subagent calls. One batch is collectively bounded by the parent's remainder — N parallel children cannot each spend the full amount. The grant travels RunInput.subagentTokenBudget -> eve.subagentTokenBudget serialized context key -> child session creation, mirroring the existing subagentDepth plumbing. The fixed 5M default is gone.
• A completed child's usage folds into the parent's session totals on resume (resolvePendingRuntimeActions), so the parent's limit check and the shares granted to later batches account for what the tree already spent. Turn totals stay untouched: child spend is attributed by the caller-side invoke_agent span from feat(eve): surface subagent usage to callers #488, so turn tags don't double-count.
• maxInputTokensPerSession / maxOutputTokensPerSession accept false to uncap an axis explicitly. An uncapped parent delegates uncapped children regardless of fan-out; an authored child limit applies only when tighter than the parent's grant, and a child authoring false still gets the grant. A child can restrict itself, never exempt itself.
• Durable sessions rehydrate persisted limits verbatim instead of re-resolving defaults, so an uncapped session stays uncapped across rehydration. Persisted limits are already resolved at creation; re-applying the root default on hydration would silently re-cap.

Why this shape

The alternative was keeping a smaller fixed subagent default. Any fixed number is wrong twice: too generous when the parent is nearly spent, too stingy for a deep task under a large budget. The parent's remainder split across the batch is the only grant with grounding at dispatch time, and #488 made it computable. This also moves toward #551 (uncapped sessions as the default) without touching the root 40M default — that removal stays with the research plan.

Remote-agent calls do not count toward the fan-out: they run on their own deployment under their own limits, so they never dilute the local shares.

Known slack

• A child that underspends its share doesn't return the surplus to siblings in the same batch; the surplus becomes visible to the next batch after fold-back.
• Failed child runs carry no usage (pre-existing in the result contract, see delegated-parent-notification.ts), so an errored child's spend doesn't draw down the parent.

Review notes

Rebased over #528 (maxSubagents) with one trivial conflict in the manifest limits schema. session.test.ts hydration expectations changed with the verbatim-rehydration semantics: no stored limits now means uncapped, not re-defaulted.

[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 7, 2026 1:15am
eve-docs-1644	Ready	Preview, Comment, Open in v0	Jul 7, 2026 1:15am
eve-docs-4759	Ready	Preview, Comment, Open in v0	Jul 7, 2026 1:15am

[github-actions]

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

Key takeaways

• No notable deltas vs main (5ef4ec6).

Delta vs main (5ef4ec6)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	3.53 MB	3.53 MB	+2.4 kB ⚠️
Package	Unpacked publish size	12.81 MB	12.82 MB	+8.4 kB ⚠️
Package	Installed footprint	51.90 MB	51.91 MB	+8.4 kB ⚠️
Package	Published files	2437	2441	+4
Package	Installed files	5664	5668	+4
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	9.24 MB	9.25 MB	+2.2 kB ⚠️
Runtime	Public routes	9	9	0

Changed function payloads vs main (5ef4ec6) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/.well-known/workflow/v1/flow.func	changed	5.76 MB	5.77 MB	+2.5 kB ⚠️	none
functions/__server.func	changed	3.48 MB	3.48 MB	-244 B ✅	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	91.69 MB	91.69 MB	+8.4 kB ⚠️
Installed packages	120	120	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	26.97 MB	26.98 MB	+8.4 kB ⚠️
devDependency package bytes	4.81 MB	4.81 MB	0 B ➖

Build Metadata

• Preset: vercel
• Nitro: nitro@3.0.260610-beta
• Output directory: apps/fixtures/weather-agent/.vercel/output
• Build metadata timestamp: 2026-07-07T01:15:50.285Z
• 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: eve@0.20.0
• Package directory: packages/eve
• Tarball: 3.53 MB (eve-0.20.0.tgz)
• Unpacked payload: 12.82 MB across 2441 published files
• Installed footprint: 51.91 MB across 5668 installed files
• Installed root package: 11.54 MB
• Installed dependencies: 40.36 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: 19.18 MB (36.9%)
• eve: 11.54 MB (22.2%)
• ai: 6.34 MB (12.2%)
• zod: 5.04 MB (9.7%)
• nitro: 2.41 MB (4.6%)

Publish payload breakdown

Published file size
🟠 dist/src/compiled/experimental-ai-sdk-code-mo... [####....................] 1.51 MB 11.7%
🟡 dist/src/compiled/@workflow/core/runtime.js      [##......................] 794.4 kB 6.2%
🟡 dist/src/compiled/@vercel/sandbox/index.js       [##......................] 632.2 kB 4.9%
🟡 dist/src/compiled/@chat-adapter/slack/index.js   [#.......................] 433.8 kB 3.4%
🟡 dist/src/compiled/_chunks/workflow/attribute-... [#.......................] 371.6 kB 2.9%
🔴 Other published files                            [########################] 9.08 MB 70.8%

Installed footprint breakdown

Installed package size
🔴 @rolldown/binding-linux-x64-gnu [########################] 19.18 MB 36.9%
🔴 eve                             [##############..........] 11.54 MB 22.2%
🔴 ai                              [########................] 6.34 MB 12.2%
🔴 zod                             [######..................] 5.04 MB 9.7%
🟠 nitro                           [###.....................] 2.41 MB 4.6%
🟡 rolldown                        [#.......................] 771.7 kB 1.5%
🔴 Other installed packages        [########................] 6.63 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: 91.69 MB across 7420 installed files
• Installed packages: 120 total (114 transitive-only)
• dependencies: 4 direct packages totaling 26.98 MB
• devDependencies: 2 direct packages totaling 4.81 MB
• Other transitive package files: 59.90 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: 29.69 MB (32.4%)
• @rolldown/binding-linux-x64-gnu: 19.18 MB (20.9%)
• eve: 11.54 MB (12.6%)
• zod: 9.00 MB (9.8%)
• ai: 6.34 MB (6.9%)

Installed footprint breakdown

Installed package size
🔴 @typescript/typescript-linux-x64 [########################] 29.69 MB 32.4%
🔴 @rolldown/binding-linux-x64-gnu  [###############.........] 19.18 MB 20.9%
🔴 eve                              [#########...............] 11.54 MB 12.6%
🔴 zod                              [#######.................] 9.00 MB 9.8%
🔴 ai                               [#####...................] 6.34 MB 6.9%
🟠 @types/node                      [##......................] 2.54 MB 2.8%
🔴 Other installed packages         [###########.............] 13.40 MB 14.6%

dependencies (4)

Package	Range	Installed size	Share
@vercel/connect	0.2.2	98.6 kB	0.1%
ai	^7.0.0	6.34 MB	6.9%
eve	file:eve-0.20.0.tgz	11.54 MB	12.6%
zod	4.4.3	9.00 MB	9.8%

devDependencies (2)

Package	Range	Installed size	Share
@types/node	24.x	2.54 MB	2.8%
typescript	7.0.1-rc	2.27 MB	2.5%

Function Drill-Down

Payload Size Graph

Unique function payload size and share of total
🔴 functions/.well-known/workflow/v1/flow.func     [########################] 5.77 MB 62.4%
🟠 functions/__server.func                         [##############..........] 3.48 MB 37.6%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 5.77 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	5.77 MB
Function files	5.77 MB across 26 files
Traced dependencies	0 B
Signal	🟠 Bundled file __eve_nitro_handler__.mjs is 1.99 MB (34.6%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 __eve_nitro_handler__.mjs              [########################] 1.99 MB 34.6%
🟠 _chunks/runtime.mjs                    [############............] 983.9 kB 17.1%
🟡 _chunks/sandbox.mjs                    [#########...............] 766.3 kB 13.3%
🟡 _chunks/attribute-changes-zAifvEhb.mjs [######..................] 473.4 kB 8.2%
🟡 _libs/@ai-sdk/gateway+[...].mjs        [#####...................] 413.5 kB 7.2%
🟠 Other bundled files                    [##############..........] 1.14 MB 19.7%

🧾 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 • 3.48 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	3.48 MB
Function files	3.48 MB across 21 files
Traced dependencies	0 B
Signal	🟠 Bundled file _chunks/dev-runtime-artifacts.mjs is 914.5 kB (26.3%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 _chunks/dev-runtime-artifacts.mjs      [########################] 914.5 kB 26.3%
🟠 _chunks/runtime.mjs                    [#######################.] 891.6 kB 25.6%
🟠 _chunks/sandbox.mjs                    [####################....] 766.3 kB 22.0%
🟡 _chunks/attribute-changes-zAifvEhb.mjs [############............] 449.0 kB 12.9%
⚪ _libs/zod.mjs                          [###.....................] 114.2 kB 3.3%
🟡 Other bundled files                    [#########...............] 343.4 kB 9.9%

🧾 Vercel Config

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