Why does Basic Memory write Obsidian tags as JSON arrays instead of YAML lists?

Question

Using Basic Memory 0.14.2 (Homebrew, macOS), write_note with tags produces frontmatter like `tags: ["tag1", "tag2"]`, or `tags:
- '["system"'
- '"overview"'
- '"reference"]'` when the AI assistant passes tags as a stringified array. Obsidian expects a YAML list such as `tags:
- tag`. How do I get Obsidian-compatible tag formatting?

AgentArmorHQ team · Accepted Answer

Status: the issue is closed as COMPLETED. A contributor implemented a fix on 2025-08-24 on branch `claude/issue-132-20250824-1414` and opened a PR, but the thread does not name the release version that contains it. An earlier PR #194 did not fully address it: maintainer @phernandez said tags were still not in the desired unquoted list format and asked for a code update plus a regression test.

The root cause, from the final comment, is that the `frontmatter` library uses PyYAML's default flow-style serialization, which produces JSON-style arrays like `["tag1", "tag2"]`. The implemented fix adds `dumps_frontmatter_obsidian_compatible()` in `src/basic_memory/file_utils.py`, a custom YAML dumper that forces `default_flow_style=False`. It updates the serialization points including `src/basic_memory/services/entity_service.py` (2 locations), and adds parsing for stringified JSON arrays so `tags=["system", "overview", "reference"]` written by an AI assistant is normalized to:

```yaml
tags:
- system
- overview
- reference
```

If you are still on 0.14.2, you are seeing the old behavior until a build with this fix is released. As general advice, make sure the caller passes tags as a real list, not as a stringified array; the mangled entries shown in the issue happened because the array was converted to a string before being passed to `write_note`. Review the PR or upgrade once a release containing the fix is available.

AgentArmorHQ team · Answer

**What a GitHub user tried on GitHub** (Outcome unclear)

The issue body proposed modifying tag serialization in `src/basic_memory/markdown/` and `src/basic_memory/services/entity_service.py` to emit YAML list syntax with unquoted values while keeping backward compatibility when reading old files.

Source: https://github.com/basicmachines-co/basic-memory/issues/132

AgentArmorHQ team · Answer

**What @egoes tried on GitHub** (Didn't work)

A user on Basic Memory 0.14.2 (Homebrew, macOS) passed `tags=["system", "overview", "reference"]` to `write_note`. Because the AI assistant stringified the array, the frontmatter became `tags:
- '["system"'
- '"overview"'
- '"reference"]'`, so the earlier fix had not resolved it for them.

Source: https://github.com/basicmachines-co/basic-memory/issues/132#issuecomment-3092219392

AgentArmorHQ team · Answer

**What @phernandez tried on GitHub** (Didn't work)

The maintainer reviewed PR #194, found tags were still not formatted as the expected unquoted YAML list, and asked for the code to be updated and a test added to verify proper formatting.

Source: https://github.com/basicmachines-co/basic-memory/issues/132#issuecomment-3218144783

AgentArmorHQ team · Answer

**What @claude tried on GitHub** (Outcome unclear)

A contributor completed an implementation on 2025-08-24: a custom Obsidian-compatible YAML serializer, handling of both array and stringified-array inputs, updated serialization call sites, and a test suite covering `write_note` and edge cases. A PR was created, but the thread does not confirm merge or release.

Source: https://github.com/basicmachines-co/basic-memory/issues/132#issuecomment-3218144979

Why does Basic Memory write Obsidian tags as JSON arrays instead of YAML lists?

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Why does Basic Memory write Obsidian tags as JSON arrays instead of YAML lists?

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