codeburn/docs/providers/open-design.md

Open Design

Open Design coding agent. Records an event-stream JSONL log per run, with token usage attached to periodic usage events rather than one entry per turn.

• Source: src/providers/open-design.ts
• Loading: eager (src/providers/index.ts)
• Test: tests/providers/open-design.test.ts (7 tests, fixture-based)

Where it reads from

OS	Default path
macOS	~/Library/Application Support/Open Design
Windows	%APPDATA%/Open Design
Linux	~/.config/Open Design

$CODEBURN_OPEN_DESIGN_DIR overrides the default. Discovery accepts several base-directory shapes and normalizes them all down to <namespace>/data/runs/<runId>/events.jsonl: a namespaces root (<base>/namespaces/<ns>/data/runs), a data dir, a runs dir, or a plain root, tried at both <base>/data/runs and <base>/runs. Results are deduplicated by resolved path so an ambiguous root does not double-count a run.

Storage format

JSONL, one event object per line: { id, event, data, timestamp }. A start event, or an agent event with data.type === 'status', carries the current model in data.model. An agent event with data.type === 'usage' carries data.usage.{input_tokens, output_tokens, cached_read_tokens, thought_tokens}.

Pricing

Recomputed locally via calculateCost. input_tokens is inclusive of cached reads, so the parser subtracts cached_read_tokens before pricing fresh input; thought_tokens (reasoning) bills at the output rate and is folded into the output argument passed to calculateCost.

Caching

None at the provider level.

Deduplication

Per open-design:<sessionId>:<eventId>, where sessionId is the run's directory name and eventId is the event's own id, falling back to a per-line counter when the event has none.

Quirks

• A usage event needs a model first. Usage is only recorded once a start or status event has set currentModel; a usage event that arrives before any model is known is dropped rather than attributed to unknown.
• No tool or bash-command tracking. tools and bashCommands are always empty; the event stream does not expose per-call tool names today.
• Only two models have display-name overrides: openai-codex:gpt-5.5 maps to GPT-5.5, and glm-5.2 / GLM-5.2 both map to GLM-5.2. Any other model string displays as-is.

When fixing a bug here

1. Confirm which base-directory shape the install actually uses; CODEBURN_OPEN_DESIGN_DIR is the fastest way to point discovery at a specific data, runs, or namespaces root while testing.
2. If costs are $0, check whether a start or status event ever set the model before the usage event arrived for that run.
3. New fixtures go under tests/fixtures/open-design/ and tests/providers/open-design.test.ts.