Windsurf / Devin Desktop

• ID: windsurf
• Store: ~/.codeium/windsurf/cascade/<cascade-id>.pb, one file per Cascade conversation
• Config root: ~/.codeium/windsurf on macOS and Linux, %USERPROFILE%\.codeium\windsurf on Windows
• Read overrides: DEJA_WINDSURF_ROOT replaces the config root
• Format: an AES-256-GCM sealed CortexTrajectory protobuf
• Needs: nothing
• Resume: none — devin-desktop --sessions opens the Sessions window, and no command takes a conversation id

Windsurf now ships as Devin Desktop. The bundle still carries the Windsurf

internals (com.exafunction.windsurf, extensions/windsurf, the language

server's --codeium_dir .codeium/windsurf), and the Cascade store is the same,

so deja reads both under one id. The state.vscdb databases hold no Cascade

transcripts on 3.5.17.

Each file is nonce(12) || ciphertext || tag(16): AES-256-GCM, no additional

data, and the key the language server carries as a constant,

safeCodeiumworldKeYsecretBalloon. deja authenticates a file before decoding

it. One that fails is skipped whole and counted: deja doctor and the index

run say windsurf 3 trajectories failed authentication rather than show a

shorter history.

Inside is a CortexTrajectory. The fields deja reads, by number from the

generated descriptors in the bundled extension:

The session id is cascade_id, which is also the file name. The project is

the first workspace's git root when it has one, else its folder; both are

file:// URIs. The title is renamed_title, else the first prompt. A typed

prompt is user_response, with query read when that is empty; the reply is

response, with modified_response read when that is empty. Thinking, tool

calls, edits, terminal state and plans are left out. Timestamps come from each

step's metadata, then the trajectory's.

Last verified: 2026-07-28

Known quirks and drift

• Reply precedence is unverified. The live trajectory examined on 3.5.17

was refused by the service before the model answered, so which of

response and modified_response a successful turn fills has not been

seen. deja reads response first.

• Error-only trajectories. A refused turn still writes a trajectory: the

prompt, then steps with no planner response. It is indexed with its prompts.

• Not read. implicit/*.pb (context trajectories), brain/ (plans and

other state) and the newer ACP session store are different sources from

Cascade.

• Unknown fields are skipped by wire type, so a schema that grows keeps

reading. A file that authenticates and does not decode is reported as an

unreadable path and costs only itself.

• Wiring. deja install windsurf writes the server into

~/.codeium/windsurf/mcp_config.json under mcpServers, the file Cascade

reads. devin-desktop --add-mcp writes the Code OSS-level User/mcp.json

instead, which Cascade does not read.

The same install puts deja's guidance block in

~/.codeium/windsurf/memories/global_rules.md, which Cascade keeps in

context always. Cascade caps that file at 6,000 characters including the

user's own rules, so a file that would pass the cap with the block is left

as it is, and install and deja doctor say so. The skill goes to

skills/deja-history/SKILL.md and /deja to

global_workflows/deja.md. Workflows get no argument substitution, so the

workflow names the query in words.

• Hooks are not wired. Cascade runs ~/.codeium/windsurf/hooks.json, but

none of a hook's output reaches the model: exit 2 only blocks, and

show_output is shown in the UI and is not offered for pre_user_prompt

(docs). The rule, the skill and

the workflow come from the docs and have not been run against the app.

• Checked against Devin Desktop 3.5.17 on macOS (Code OSS 1.110.1):

runtime paths, the envelope against a live file, and descriptor field

numbers (#308). The fixtures are synthetic, built by

internal/sources/windsurf_fixture_test.go.

deja reads this format and 41 others, and turns what it finds into memory your agents can search. See the harness matrix for what is wired where, or install it and search your own history.

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