Devin

Cognition Devin CLI local usage tracking.

• Source: src/providers/devin.ts
• Loading: eager (src/providers/index.ts)
• Test: tests/providers/devin.test.ts (336 lines)

Where it reads from

Devin CLI data lives under:

~/.local/share/devin/cli/

The MVP usage source is transcript JSON:

~/.local/share/devin/cli/transcripts/*.json

The provider also reads:

~/.local/share/devin/cli/sessions.db

sessions.db is enrichment only. It supplies project path/name, model fallback, timestamp fallback, and hidden-session filtering. It is not the source of usage or billing.

Configuration

Devin reports spend in ACUs. CodeBurn reports provider cost through costUSD, so Devin stays disabled until a positive finite ACU-to-USD rate is configured:

{
  "devin": {
    "acuUsdRate": 2.25
  }
}

The config file is:

~/.config/codeburn/config.json

The macOS Settings window writes this value from the Devin tab. There is no environment-variable override and no default rate. Do not hardcode a universal ACU price; Devin ACU pricing is account/contract dependent.

When the rate is missing or invalid, discoverSessions() returns [] and the parser yields no calls. Devin remains registered as a provider, but it does not appear in CLI/UI results until configured.

Storage format

Transcript root is a JSON object following the ATIF-v1.4 trajectory schema, with Devin-specific additions such as per-step metadata. The parser does not validate schema_version; it only requires a parseable object with steps[].

Core fields include session_id, agent.model_name, and steps[].

Each counted step can provide:

• step_id
• metadata.committed_acu_cost
• metadata.metrics.input_tokens
• metadata.metrics.output_tokens
• metadata.metrics.cache_creation_tokens
• metadata.metrics.cache_read_tokens
• metadata.created_at
• metadata.generation_model
• metadata.request_id
• tool_calls[].function_name

User-input steps (metadata.is_user_input === true) are skipped. Non-user steps are included only if they have positive ACU usage or positive token usage.

Pricing

metadata.committed_acu_cost is per step, not cumulative. The provider converts each step with:

costUSD = committed_acu_cost * devin.acuUsdRate

Token-only steps are still included when they have positive token metrics, but their costUSD is 0 if committed_acu_cost is absent.

src/parser.ts preserves Devin's provider-supplied costUSD instead of re-pricing it through LiteLLM.

sessions.db enrichment

The provider currently reads these columns from sessions:

Column	Use
id	join key with transcript session_id during parsing; discovery uses the transcript filename before .json
working_directory	projectPath and derived project name
model	model fallback
title	project name fallback
created_at	timestamp fallback
last_activity_at	preferred session timestamp fallback
hidden	skip hidden sessions

message_nodes, prompt_history, and tool_call_state are not parsed yet.

Timestamps

Step timestamps come from metadata.created_at, falling back to sessions.last_activity_at, then sessions.created_at.

Transcript step timestamps are passed through as ATIF string timestamps. Numeric normalization is only applied to sessions.db timestamps:

• less than 10_000_000_000: seconds
• otherwise: milliseconds

Model Resolution

Model names resolve in this order:

1. step.metadata.generation_model
2. step.model_name
3. transcript.agent.model_name
4. sessions.model
5. devin

Caching

No provider-level cache.

The normal session cache stores parsed provider calls, but Devin is always reparsed by src/parser.ts because sessions.db can change without the transcript JSON fingerprint changing.

Deduplication

devin:<sessionId>:<step.step_id>

The provider name is part of the key via the devin: prefix.

Quirks

• The transcript directory has usage; sessions.db is enrichment only.
• committed_acu_cost is per-generation/per-step ACU usage. Never treat it as cumulative.
• There is no default ACU-to-USD rate. Missing config intentionally hides Devin.
• Hidden sessions from sessions.db are skipped in discovery and parsing.
• Tool names come directly from tool_calls[].function_name; the provider assumes valid ATIF tool-call records.
• If SQLite is unavailable or sessions.db cannot be opened, the provider still parses transcripts without enrichment.

When fixing a bug here

1. First check whether ~/.config/codeburn/config.json contains a valid devin.acuUsdRate. Without it, no Devin sessions should appear.

2. For usage total bugs, compare against:

   jq '[.steps[] | select(.metadata.committed_acu_cost != null) | .metadata.committed_acu_cost] | add' ~/.local/share/devin/cli/transcripts/<session>.json

3. If project/model/timestamp metadata is wrong, inspect sessions.db, not the transcript.

4. If a hidden session appears, check the hidden column. Discovery can only hide sessions whose transcript filename matches sessions.id; parsing uses the transcript session_id when present.

5. Run tests/providers/devin.test.ts after parser changes. It covers ACU conversion, disabled-until-configured behavior, timestamp parsing, deduplication, hidden sessions, and sessions.db enrichment.