feat(eve): add the /traces conversation viewer to the dev TUI

[chadhietala]

Stacked on #1444 — base is trace-local-reader, review that first. This is the core layer of the /traces stack: capture (#1443) and reading (#1444) sit below; provider-executed tool cards (#1445), drag-to-select copy (#1446), and chrome polish (#1447) sit above.

eve dev writes a local trace spool while you chat, but inspecting it meant leaving the TUI for eve traces and reading span trees. This adds /traces: a full-screen viewer that re-tells a trace as the conversation it recorded.

What changed

/traces opens on the terminal's alternate screen (the transcript's scrollback stays untouched underneath) and renders the trace as cards, discovered from the span tree and ordered by when their spans started:

• the system prompt collapsed at the top with a token estimate; user and assistant message cards; tool cards with Input:/Output: sections. Assistant cards carry model, duration, token, and gateway-cost metadata plus a dim Thought: reasoning section; error spans paint their whole card red
• work a subagent performed interleaves in time order — between the parent's dispatch and its resumed reply — with a dim subagent:<name> badge on every card of the delegated turn, and the delegated prompt rendered as a task card rather than a user message (uses the lineage attributes from feat(eve): attribute a subagent turn to the call that dispatched it #1433)
• cards expand/collapse with ←/→ or a mouse click (SGR reporting); the viewport scrolls by lines with keys or the wheel, so an expanded card taller than the screen is reachable to its end
• Enter opens a right-hand attributes drawer that stays metadata-only — status, timing, ids, non-payload OTLP attributes — since the cards already carry the payloads
• the spool is polled about once a second, so spans from the live session stream in (● live badge); [/] cycles traces, and the viewer opens on the current chat session's trace by matching session ids against the spool

The state is a pure reducer (trace-viewer-state.ts) with rendering split from it (trace-view.ts, trace-conversation.ts), a store that caches parsed segments so the 1 s poll only touches new files, and a session controller owning the poll/repaint lifecycle — all testable without a TTY. Keys survive in-flight polls: navigation during a slow disk read is re-applied against the fresh data rather than clobbered.

Verification

Unit coverage for the store, reducer, frame renderer, and conversation builder (819 tests under cli/dev/tui at this layer). test/tui-client/tui-traces.ts drives the real runner through a pty: open → arrow-key fold → mouse-click expand → drawer metadata-only → subagent badge → trace cycling → escape → empty spool. Repeated end-to-end use against real spool data (fixtures through the gateway). Sweep green; full suite at the stack top.

[vercel]

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Project	Deployment	Actions	Updated (UTC)
eve-docs	Ready	Preview	Jul 31, 2026 11:14am
eve-docs-4759	Ready	Preview, v0	Jul 31, 2026 11:14am

[github-actions]

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

Key takeaways

• No notable deltas vs trace-local-reader (436af4e).

Delta vs trace-local-reader (436af4e)

Area	Metric	Baseline	Current	Delta
Package	Packed tarball	7.63 MB	7.65 MB	+15.7 kB ⚠️
Package	Unpacked publish size	28.81 MB	28.86 MB	+48.9 kB ⚠️
Package	Installed footprint	85.78 MB	85.83 MB	+48.9 kB ⚠️
Package	Published files	2876	2890	+14
Package	Installed files	6669	6683	+14
Runtime	Unique function payloads	2	2	0
Runtime	Total function bytes	16.82 MB	16.82 MB	-40 B ✅
Runtime	Public routes	11	11	0

Changed function payloads vs trace-local-reader (436af4e) (2)

Function	Status	Baseline	Current	Delta	Route changes
functions/__server.func	changed	8.41 MB	8.41 MB	-20 B ✅	none
functions/.well-known/workflow/v1/flow.func	changed	8.41 MB	8.41 MB	-20 B ✅	none

eve init install

Metric	Baseline	Current	Delta
Installed footprint	124.19 MB	124.24 MB	+48.9 kB ⚠️
Installed packages	128	128	0
dependencies	4	4	0
devDependencies	2	2	0
Dependency package bytes	43.18 MB	43.23 MB	+48.9 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: 2026-07-31T11:14:56.123Z
• 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@0.29.2
• Package directory: packages/eve
• Tarball: 7.65 MB (eve-0.29.2.tgz)
• Unpacked payload: 28.86 MB across 2890 published files
• Installed footprint: 85.83 MB across 6683 installed files
• Installed root package: 27.50 MB
• Installed dependencies: 58.33 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: 27.50 MB (32.0%)
• @rolldown/binding-linux-x64-gnu: 19.28 MB (22.5%)
• @rolldown/binding-wasm32-wasi: 10.66 MB (12.4%)
• ai: 6.56 MB (7.6%)
• zod: 5.07 MB (5.9%)

Publish payload breakdown

Published file size
🔴 dist/src/compiled/shadcn-registry/index.js       [########################] 13.15 MB 45.6%
🟠 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                            [#######################.] 12.62 MB 43.7%

Installed footprint breakdown

Installed package size
🔴 eve                             [########################] 27.50 MB 32.0%
🔴 @rolldown/binding-linux-x64-gnu [#################.......] 19.28 MB 22.5%
🔴 @rolldown/binding-wasm32-wasi   [#########...............] 10.66 MB 12.4%
🔴 ai                              [######..................] 6.56 MB 7.6%
🔴 zod                             [####....................] 5.07 MB 5.9%
🟠 undici                          [###.....................] 3.50 MB 4.1%
🔴 Other installed packages        [############............] 13.26 MB 15.4%

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: 124.24 MB across 8551 installed files
• Installed packages: 128 total (122 transitive-only)
• dependencies: 4 direct packages totaling 43.23 MB
• devDependencies: 2 direct packages totaling 5.04 MB
• Other transitive package files: 75.97 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 (22.5%)
• eve: 27.50 MB (22.1%)
• @rolldown/binding-linux-x64-gnu: 19.28 MB (15.5%)
• @rolldown/binding-wasm32-wasi: 10.66 MB (8.6%)
• zod: 9.02 MB (7.3%)

Installed footprint breakdown

Installed package size
🔴 @typescript/typescript-linux-x64 [########################] 27.95 MB 22.5%
🔴 eve                              [########################] 27.50 MB 22.1%
🔴 @rolldown/binding-linux-x64-gnu  [#################.......] 19.28 MB 15.5%
🔴 @rolldown/binding-wasm32-wasi    [#########...............] 10.66 MB 8.6%
🔴 zod                              [########................] 9.02 MB 7.3%
🔴 ai                               [######..................] 6.56 MB 5.3%
🔴 Other installed packages         [####################....] 23.26 MB 18.7%

dependencies (4)

Package	Range	Installed size	Share
@vercel/connect	0.4.2	135.8 kB	0.1%
ai	^7.0.38	6.56 MB	5.3%
eve	file:eve-0.29.2.tgz	27.50 MB	22.1%
zod	4.4.3	9.02 MB	7.3%

devDependencies (2)

Package	Range	Installed size	Share
@types/node	24.x	2.54 MB	2.0%
typescript	7.0.2	2.50 MB	2.0%

Function Drill-Down

Payload Size Graph

Unique function payload size and share of total
🔴 functions/.well-known/workflow/v1/flow.func     [########################] 8.41 MB 50.0%
🔴 functions/__server.func                         [########################] 8.41 MB 50.0%

Top Function Payloads

🟠 functions/.well-known/workflow/v1/flow.func • 1 public route • 8.41 MB

Metric	Value
Public routes	/.well-known/workflow/v1/flow
Runtime	nodejs24.x
Handler	index.mjs
Payload	8.41 MB
Function files	8.41 MB across 43 files
Traced dependencies	0 B
Signal	🟠 Bundled file index.mjs is 2.31 MB (27.5%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [########################] 2.31 MB 27.5%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.59 MB 18.9%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.7%
🟡 _chunks/sandbox.mjs             [########................] 768.8 kB 9.1%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.8 kB 5.1%
🟠 Other bundled files             [########################] 2.32 MB 27.6%

🧾 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 • 8.41 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	8.41 MB
Function files	8.41 MB across 43 files
Traced dependencies	0 B
Signal	🟠 Bundled file index.mjs is 2.31 MB (27.5%)

🟠 🔎 Dependency Analysis

📦 Bundled files:

Bundled file size
🟠 index.mjs                       [########################] 2.31 MB 27.5%
🟠 _chunks/runtime-artifacts.mjs   [################........] 1.59 MB 18.9%
🟡 _libs/undici.mjs                [##########..............] 980.5 kB 11.7%
🟡 _chunks/sandbox.mjs             [########................] 768.8 kB 9.1%
🟡 _libs/@ai-sdk/gateway+[...].mjs [####....................] 432.8 kB 5.1%
🟠 Other bundled files             [########################] 2.32 MB 27.6%

🧾 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: 2.01 s -> 2.18 s (+162.6 ms) vs trace-local-reader (436af4e).
• Timing is informational: shared GitHub runners are too variable for a hard timing budget.

Detailed phase timings vs `trace-local-reader (436af4e)`

Phase	Baseline	Current	Delta
extension.check	12.4 ms	6.7 ms	-5.7 ms
project.resolve	13.7 ms	6.5 ms	-7.2 ms
workspace.create	1.2 ms	1.6 ms	+0.4 ms
host.prepare	252.5 ms	375.0 ms	+122.5 ms
vercel.service-prefix.resolve	2.9 ms	2.5 ms	-0.4 ms
nitro.create	211.1 ms	206.9 ms	-4.2 ms
sandbox.prewarm	196.0 ms	248.1 ms	+52.1 ms
nitro.cache.prepare	0.2 ms	0.3 ms	+0.1 ms
nitro.prepare	0.9 ms	0.9 ms	0.0 ms
nitro.public-assets	0.7 ms	0.8 ms	+0.1 ms
nitro.prerender	0.6 ms	0.5 ms	-0.1 ms
nitro.bundle	1.29 s	1.30 s	+4.2 ms
nitro.cache.write	0.6 ms	0.5 ms	-0.1 ms
vercel.workflow-function.materialize	21.8 ms	21.8 ms	0.0 ms
agent-summary.emit	0.6 ms	0.5 ms	-0.1 ms
nitro.close	0.1 ms	0.1 ms	0.0 ms
output.publish	3.8 ms	4.6 ms	+0.8 ms
workspace.remove	2.1 ms	2.3 ms	+0.2 ms

[vercel]

Expand/collapse scroll recalculation in reduceTraceViewerKey uses stale (pre-toggle) card line counts, so a just-expanded card taller than the viewport stays clipped at the bottom.