fix(settings): validate condenser Max Size and block invalid values

[VascoSch92]

• A human has tested these changes.

Summary

Fixes #863. The Condenser "Max Size" field accepted values the backend rejects (negatives, below the minimum, non-integers), so users could only discover the problem via an unclear error when saving.

The backend SDK (CondenserSettings.max_size) enforces ge=20 with no upper bound, so any value below 20 — including the spinner going under 0 — fails validation on save. This change surfaces those rules in the UI as immediate, localized feedback.

Issue Number

#863

Changes

• Constrain the input. Added a condenser.max_size entry to FIELD_METADATA (min: 20, step: 1), mirroring the existing llm.top_p / llm.temperature constraints. This floors the
  native number spinner at 20 and matches the backend ge=20.
  • Live validation feedback. SchemaField now shows an inline red message as the user types, via the existing SettingsInput error prop (the same pattern used in backend-form-modal /
    edit-automation-modal):
    • below the minimum → "Value must be at least 20."
    • non-integer (e.g. 0.9) → "Please enter a whole number."
    • non-numeric entry (e.g. a typed letter) → "Please enter a whole number." Detected via the input's native validity.badInput flag, read from a raw input event listener (React's
    • non-numeric entry (e.g. a typed letter) → "Please enter a whole number." Detected via the input's native validity.badInput flag, read from a raw input event listener (React's onChange is skipped when a number input's value
      stays empty, so it can't be relied on here).
  • i18n. Added SCHEMA$ERROR$WHOLE_NUMBER and SCHEMA$ERROR$MIN_VALUE (with {{min}} interpolation) across all 15 locales.

Video/Screenshots

Screen.Recording.2026-05-29.at.12.33.40.mov

Type

• Bug fix
• Feature
• Refactor
• Breaking change
• Docs / chore

Notes

• The validation is generic to numeric SchemaFields, not condenser-specific.
• The min: 20 floor is hardcoded on the frontend because the schema endpoint doesn't expose pydantic's min/max; a comment links it to the SDK constraint so it stays in sync.
• Browser caveat: in Chrome, type="number" blocks letter keystrokes outright, so the non-numeric message only appears in browsers that allow typing them (Firefox/Safari); floats and below-minimum work everywhere.

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🐳 Docker images for this PR

• GHCR package: https://github.com/OpenHands/agent-canvas/pkgs/container/agent-canvas

Component	Value
Image	ghcr.io/openhands/agent-canvas
Architectures	amd64, arm64
Agent Server	ghcr.io/openhands/agent-server:1.24.0-python
Automation	openhands-automation==1.0.0a5
Commit	a5d083896fd2aaea4cdb166b6b4005ae45be2380

Pull (multi-arch manifest)

# Multi-arch manifest — Docker automatically pulls the correct architecture
docker pull ghcr.io/openhands/agent-canvas:sha-a5d0838

Run

docker run -it --rm \
  -p 8000:8000 \
  ghcr.io/openhands/agent-canvas:sha-a5d0838

All tags pushed for this build

ghcr.io/openhands/agent-canvas:sha-a5d0838-amd64
ghcr.io/openhands/agent-canvas:863-bug-condenser-max-number-of-events-indicator-can-go-under-0-amd64
ghcr.io/openhands/agent-canvas:pr-925-amd64
ghcr.io/openhands/agent-canvas:sha-a5d0838-arm64
ghcr.io/openhands/agent-canvas:863-bug-condenser-max-number-of-events-indicator-can-go-under-0-arm64
ghcr.io/openhands/agent-canvas:pr-925-arm64
ghcr.io/openhands/agent-canvas:sha-a5d0838
ghcr.io/openhands/agent-canvas:863-bug-condenser-max-number-of-events-indicator-can-go-under-0
ghcr.io/openhands/agent-canvas:pr-925

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• Individual architecture tags (e.g., sha-a5d0838-amd64) are also available if needed

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Project	Deployment	Actions	Updated (UTC)
agent-canvas	Ready	Preview, Comment	May 29, 2026 12:13pm

[all-hands-bot]

✅ Review complete.

This review was performed through OpenHands Cloud Automation. You can log in and view the conversation here.

[all-hands-bot]

Overall this is a clean, well-scoped fix. The PR correctly constraints condenser.max_size at the UI level to match the backend's ge=20 rule, and the approach — extracting a pure getNumericFieldError function and using the native bad-input flag for unparseable entries — is sound. Good test coverage and full i18n for all 15 locales. A few observations below.

This review was generated by an AI agent (OpenHands) on behalf of the user through OpenHands Automation. View conversation

[github-actions]

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✅ 7 snapshots changed — acknowledged via the update-snapshots label. New baselines will be uploaded when this PR merges.

Category	Count
🔴 Changed	7
🆕 New	0
✅ Unchanged	66
Total	73

🔴 Changed snapshots (7)

backends-extended

backend-after-switch

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mcp-page — 5 snapshots

mcp-custom-server-1-editor-open

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mcp-custom-server-editor

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mcp-empty-installed

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mcp-search-filtered

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mcp-slack-install-1-marketplace

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settings-page

settings-page

Expected (main)	Actual (PR)	Diff

✅ Unchanged snapshots (66)

archived-conversation

• conversation-panel-with-archived-badges
• conversation-view-archived
• conversation-view-sandbox-error

automations

• automations-delete-modal
• automations-list-active-inactive
• automations-no-automations
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backends-extended

• backend-add-blank-disabled
• backend-add-cloud-advanced-open
• backend-add-cloud-no-key-disabled
• backend-add-cloud-with-key-enabled
• backend-add-form-partially-filled
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• backend-add-local-ready
• backend-add-name-only-disabled
• backend-add-two-column-layout
• backend-add-whitespace-host-disabled
• backend-cancel-nothing-saved
• backend-dropdown-two-backends
• backend-edit-prefilled
• backend-manage-after-removal
• backend-manage-two-listed
• backend-remove-cancelled
• backend-remove-confirmation
• backend-switch-overlay

backends

• backend-add-modal
• backend-manage-modal
• backend-selector-open

changes-tab

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mcp-page

• mcp-custom-server-2-url-filled
• mcp-custom-server-3-all-filled
• mcp-custom-server-4-installed
• mcp-slack-install-2-modal
• mcp-slack-install-3-filled
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onboarding

• onboarding-step-0-choose-agent
• onboarding-step-1-check-backend
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projects-workspace-browser

• projects-workspace-browser

settings-page

• add-backend-modal
• analytics-consent-modal
• home-screen
• settings-app-page

settings-secrets

• secrets-add-form-filled
• secrets-add-form
• secrets-after-save
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settings-verification

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Generated by the Snapshot Tests workflow. This comment was created by an AI agent (OpenHands) on behalf of the repo maintainers.