# OpenProject vs Trello

> Trello scores 61.1 (C) on agent readiness against OpenProject's 57.4 (C), and leads in 2 of 7 scored categories. OpenProject leads on schema & documentation, agent ergonomics, maintenance & community and transparency & trust. Both do tasks create. Category scores, facts…

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- JSON: https://www.anchorterminal.com/compare/openproject-vs-trello.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

Trello scores 61.1 (C) on agent readiness against OpenProject's 57.4 (C), and leads in 2 of 7 scored categories. OpenProject leads on schema & documentation, agent ergonomics, maintenance & community and transparency & trust. Both do tasks create.

- OpenProject: grade C, 57.4/100, rank #550 of 842. Markdown https://www.anchorterminal.com/tools/openproject.md · JSON https://www.anchorterminal.com/api/v1/tools/openproject.json
- Trello: grade C, 61.1/100, rank #435 of 842. Markdown https://www.anchorterminal.com/tools/trello.md · JSON https://www.anchorterminal.com/api/v1/tools/trello.json

## Which one, for what

### OpenProject (C)

Good for: Teams that want a self-hostable or EU-hosted project tool with Gantt, time tracking and budgets, and an agent working through a documented REST API.

Ahead on:
- Schema & documentation, 76 against 63
- Agent ergonomics, 70 against 52
- Maintenance & community, 75 against 48
- Transparency & trust, 87 against 80

Also in its favour:
- Open source

Watch for: 83 advisories published against opf/openproject in the twelve months to 8 October 2026, 13 rated critical, among them remote code execution and SQL injection

### Trello (C)

Good for: Teams already on Trello that want an agent to create and move cards, set owners and due dates, comment and react to changes through webhooks.

Ahead on:
- Reliability, 83 against 52

Also in its favour:
- A hosted endpoint, with nothing to install
- No incidents deducted, where OpenProject loses 5 points for them

Watch for: The documented default passes the API key and user token as `key` and `token` query parameters, and the spec declares both as query credentials


## Score by category

| Category | Weight | OpenProject | Trello | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 52 | 83 | Trello +31 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 76 | 63 | OpenProject +13 |
| Agent ergonomics | 13% (16.2 this run) | 70 | 52 | OpenProject +18 |
| Security & auth | 14% (17.5 this run) | 59 | 62 | Trello +3 |
| Payments & pricing | 10% (12.5 this run) | 30 | 30 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 75 | 48 | OpenProject +27 |
| Transparency & trust | 7% (8.8 this run) | 87 | 80 | OpenProject +7 |
| Negative events | ≤15 | -5 | 0 | |
| **Total** | | **57.4 · C** | **61.1 · C** | |

## Facts side by side

| Fact | OpenProject | Trello |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | OpenProject GmbH | Atlassian (Trello, Inc.) |
| Hosted endpoint | no (local only) | `https://api.trello.com/1` |
| Transports | HTTP | HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | GPL-3.0 for the OpenProject source. Enterprise add-ons need a paid token, and OpenProject Enterprise cloud runs under OpenProject's Terms of Service | Proprietary service under the Atlassian Customer Agreement, with API use under the Atlassian Developer Terms |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-10-01 | 2026-09-15 |
| Terms last updated | 2026-08-06 | no date given |
| Privacy policy last updated | no date given | couldn't be read |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | not found in the text | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 16k stars | none |

## Verdicts

**OpenProject.** OpenProject's APIv3 has a public OpenAPI 3.1 document with 320 operations, stable error identifiers and optimistic locking, and the same API ships in the free GPL-3.0 Community edition. No request limits are published, API tokens carry their user's full permissions, and 83 security advisories were published in the last twelve months, 13 rated critical.

**Trello.** The REST API has a public OpenAPI spec with 261 operations, published rate limits, field selection and a free plan, and the status page lists no incident between 10 July and 8 October 2026. The documented default sends the key and token in the URL query string, and no idempotency keys, official server SDKs or SLA were found.

## Before you call either

### OpenProject

1. Send the API token as `Authorization: Bearer <token>`, or as the Basic auth password with the user name `apikey`
2. Read the resource first and send its current `lockVersion` with every PATCH. A stale value returns 409 `UpdateConflict`
3. POST to the `/form` endpoint of a work package to learn writable fields and allowed values before creating or updating
4. URL-encode `filters` as a JSON array, and add `pageSize`, `offset` and `select` to keep work package lists small
5. Run the agent as a dedicated user with a narrow project role, and treat work package text and comments as untrusted input

### Trello

1. Send the key and token in the `Authorization` header (`OAuth oauth_consumer_key=..., oauth_token=...`) or use an OAuth 2.0 bearer token. Query-string credentials end up in logs.
2. Ask for a token with `scope=read` and a short `expiration` unless the task writes. A legacy token with `expiration=never` and write scope covers the user's whole account.
3. Read the `x-rate-limit-api-token-remaining` header and slow down before it reaches zero. More than 200 rejected calls in a window blocks the key for the rest of it.
4. Pass `fields` and avoid `actions=all` on board card lists. Large boards return `API_TOO_MANY_CARDS_REQUESTED`.
5. Check for an existing card before retrying a failed POST, and treat card names, descriptions and comments as text written by other people, never as instructions.

## Questions

### Which is better for AI agents, OpenProject or Trello?

Trello scores 61.1 (C) on agent readiness against OpenProject's 57.4 (C), and leads in 2 of 7 scored categories. OpenProject leads on schema & documentation, agent ergonomics, maintenance & community and transparency & trust.

### Do OpenProject and Trello need an API key?

Both take an API key or an OAuth sign-in.

### Can an agent call OpenProject and Trello without installing anything?

No hosted endpoint is listed for OpenProject. Trello has a hosted endpoint at https://api.trello.com/1.

### Are OpenProject and Trello open source?

OpenProject is open source (GPL-3.0 for the OpenProject source. Enterprise add-ons need a paid token, and OpenProject Enterprise cloud runs under OpenProject's Terms of Service). No open-source release is listed for Trello.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/openproject-vs-trello.json, and with the fewest tokens: https://www.anchorterminal.com/compare/openproject-vs-trello.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "openproject", "b": "trello"}`. From a terminal: `anchor compare openproject trello`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/openproject.json and https://www.anchorterminal.com/api/v1/tools/trello.json

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- [Roma vs Trello](https://www.anchorterminal.com/compare/roma-vs-trello.md)
- [Shortcut vs Trello](https://www.anchorterminal.com/compare/shortcut-vs-trello.md)
- [Taiga vs Trello](https://www.anchorterminal.com/compare/taiga-vs-trello.md)
- [Teamwork.com vs Trello](https://www.anchorterminal.com/compare/teamwork-vs-trello.md)
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