fix: webhook notifications fail with "[object Object] is not valid JSON" by aldoeliacim · Pull Request #2641 · seerr-team/seerr

aldoeliacim · 2026-03-06T07:06:30Z

Description

Webhook notifications fail with "[object Object]" is not valid JSON for any webhook configuration saved via the API or UI.

buildPayload() in webhook.ts expects a double-encoded payload (base64 → JSON string → JSON object):

const parsedJSON = JSON.parse(JSON.parse(payloadString));

But the save routes (POST /webhook and POST /webhook/test) only single-encode the payload:

jsonPayload: Buffer.from(req.body.options.jsonPayload).toString("base64")

Saved payloads decode to raw JSON (not a JSON-wrapped string), so the first JSON.parse produces an object, and the second JSON.parse gets "[object Object]" instead of valid JSON. The default payload works because it was hardcoded as a pre-double-encoded base64 string.

The fix wraps the payload with JSON.stringify() before base64-encoding in both the save and test routes, producing the same double-encoded format that buildPayload() expects.

Fixes Webhook notifications fail with "[object Object] is not valid JSON" after saving via API/UI #2640

How Has This Been Tested?

Save a custom webhook payload via the API or UI
Trigger a test notification → succeeds (HTTP 204)
Trigger a real notification (e.g., media request) → webhook fires correctly
Verified the default payload still works (fresh install)

Screenshots / Logs (if applicable)

N/A

Checklist:

I have read and followed the contribution guidelines.
Disclosed any use of AI (see our policy)
I have updated the documentation accordingly.
All new and existing tests passed.
Successful build pnpm build
Translation keys pnpm i18n:extract
Database migration (if required)

AI Disclosure

This PR was authored by @aldoeliacim with the help of Claude Code. The bug was discovered while debugging a production Jellyseerr v3.1.0 webhook integration.

Summary by CodeRabbit

Bug Fixes
- Fixed webhook payload encoding in notification settings so configured and test webhooks now send the correctly serialized JSON payload, preventing malformed or double-encoded data when delivering notifications.

The webhook `buildPayload` method correctly double-parses the stored jsonPayload (`JSON.parse(JSON.parse(payloadString))`), expecting a base64-encoded JSON string that wraps the actual JSON template. However, the POST /webhook and POST /webhook/test routes only single-encode the payload: Buffer.from(req.body.options.jsonPayload).toString("base64") This produces a base64 string that decodes directly to the JSON object string. When buildPayload double-parses it, the first parse yields a JS object, and the second parse calls toString() on that object, producing "[object Object]" which is not valid JSON. The fix wraps the payload with JSON.stringify() before base64-encoding, matching the double-encoded format that buildPayload expects: Buffer.from(JSON.stringify(req.body.options.jsonPayload)).toString("base64") This is consistent with the default jsonPayload in settings/index.ts, which is already stored in this double-encoded format. Note: the default payload works because it was hardcoded as a double-encoded base64 string. Only payloads saved via the API (i.e., any user customization) trigger this bug.

coderabbitai · 2026-03-06T07:06:46Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: a0516c7c-0724-4b6d-a680-154df7f22de5

📥 Commits

Reviewing files that changed from the base of the PR and between 0285fee and f50c357.

📒 Files selected for processing (1)

src/components/Settings/Notifications/NotificationsWebhook/index.tsx

🚧 Files skipped from review as they are similar to previous changes (1)

src/components/Settings/Notifications/NotificationsWebhook/index.tsx

📝 Walkthrough

Walkthrough

Server endpoints now JSON.stringify() the webhook JSON payload before base64-encoding and storing; the Settings UI stopped JSON.stringify-ing the payload before sending, so the server receives the raw value and performs the required double-encoding expected by the webhook agent.

Changes

Cohort / File(s)	Summary
Server: webhook save endpoints `server/routes/settings/notifications.ts`	Wrap `req.body.options.jsonPayload` with `JSON.stringify()` before `Buffer.from(...).toString('base64')` in POST `/webhook` and POST `/webhook/test`, aligning storage format with consumer expectations.
Client: webhook UI `src/components/Settings/Notifications/NotificationsWebhook/index.tsx`	Removed `JSON.stringify` when building `options.jsonPayload` in `onSubmit` and `testSettings`; the UI now sends the raw value so the server performs stringify+base64 encoding.

Sequence Diagram(s)

mermaid
sequenceDiagram
participant UI as UI (Settings Webhook)
participant Server as Server (routes/settings/notifications)
participant DB as DB (stored config)
participant Agent as Webhook Agent (buildPayload)
participant Ext as External Webhook
UI->>Server: POST webhook payload (raw object/string)
Server->>Server: JSON.stringify(payload) -> base64 encode -> store
Server->>DB: save encoded payload
Note right of Agent: On notification trigger
Agent->>DB: read encoded payload
Agent->>Agent: base64 decode -> JSON.parse -> JSON.parse -> final object
Agent->>Ext: POST final JSON payload

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 I hopped through code with a curious squeak,
Wrapped payloads in strings so webhooks won't freak,
UI sends the object, the server does the rest,
Now JSON's well-dressed and endpoints are blessed! 🥕

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title clearly and specifically identifies the main issue being fixed (webhook double-JSON parsing error), which aligns with the primary change of adjusting JSON encoding in the save routes.
Linked Issues check	✅ Passed	The PR changes fully address the requirements in `#2640`: the server routes now JSON.stringify() the payload before base64-encoding, matching buildPayload's double-parsing expectations, and the frontend was corrected to not redundantly stringify.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to fixing the webhook double-encoding issue: server-side JSON.stringify wrapping in save routes and frontend payload passing adjustments. No unrelated modifications were introduced.

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Copilot

Pull request overview

This PR attempts to fix issue #2640 where webhook notifications fail with "[object Object] is not valid JSON". The fix adds JSON.stringify() wrapping before base64-encoding the jsonPayload in both the save and test webhook routes, aiming to produce the double-encoded format that buildPayload() in webhook.ts expects.

Changes:

Wraps req.body.options.jsonPayload with JSON.stringify() before base64-encoding in the POST /webhook save route
Applies the same JSON.stringify() wrapping in the POST /webhook/test test route

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server/routes/settings/notifications.ts

gauthier-th

Please edit the PR description according to the PR template in https://github.com/seerr-team/seerr/blob/develop/.github/PULL_REQUEST_TEMPLATE.md

The UI's onSubmit and testSettings handlers were wrapping jsonPayload with JSON.stringify() before sending to the API. Combined with the server-side JSON.stringify added in the previous commit, this produced triple-encoding (Level 3) that buildPayload()'s double-parse couldn't handle. Remove the frontend stringify so the server is the single point of encoding normalization — both UI and direct API callers now go through the same path.

aldoeliacim · 2026-03-06T14:55:00Z

Updated the PR description to follow the template. Also addressed Copilot's review — the frontend was redundantly calling JSON.stringify before sending, which combined with the server-side fix would cause triple-encoding. Removed the frontend stringify in 0285fee so the server handles all encoding normalization.

Copilot AI review requested due to automatic review settings March 6, 2026 07:06

aldoeliacim requested a review from a team as a code owner March 6, 2026 07:06

Copilot started reviewing on behalf of aldoeliacim March 6, 2026 07:06 View session

Copilot AI reviewed Mar 6, 2026

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gauthier-th requested changes Mar 6, 2026

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Merge branch 'develop' into fix/webhook-double-json-parse

f50c357

aldoeliacim requested a review from gauthier-th March 6, 2026 14:56

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fix: webhook notifications fail with "[object Object] is not valid JSON"#2641

fix: webhook notifications fail with "[object Object] is not valid JSON"#2641
aldoeliacim wants to merge 3 commits intoseerr-team:developfrom
aldoeliacim:fix/webhook-double-json-parse

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Description

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