Claude setup-token characterization fixture

• Characterized: 2026-08-11
• Claude Code: 2.1.205
• Intended repository path: packages/adapters/claude-local/src/server/__fixtures__/setup-token.md
• Safety: no real authorization URL, browser code, or token is recorded here.

Pipe stdio

Invocation: all three child streams were pipes; stdin remained open for 8 seconds, then received a syntactically shaped synthetic code followed by LF (\ ).

• Exact emitted prompt text: none.
• stdout: 0 bytes.
• stderr: 0 bytes.
• Input echo: none (the pipe path emitted nothing).
• Result: still running after 23 seconds; controlled termination was required.
• Wrapper exit: 124 from timeout; direct child termination in the equivalent harness: SIGKILL (-9).
• Conclusion: setup-token requires a PTY to expose and drive its interactive login UI. Supplying pipe stdin alone is insufficient.

PTY stdio

Normalized rendered text (spinner frames and terminal control sequences omitted):

Welcome to Claude Code v2.1.205
Opening browser to sign in…
Browser didn’t open? Use the url below to sign in (c to copy)
<REDACTED_AUTHORIZATION_URL>
Paste code here if prompted >

Authorization URL shape:

• Origin: https://claude.com
• Path: /cai/oauth/authorize
• Query keys (values redacted): client_id, code, code_challenge, code_challenge_method, redirect_uri, response_type, scope, state
• Fragment: absent
• The terminal emits the same URL through an OSC 8 hyperlink plus wrapped display text; consumers must tolerate ANSI/OSC sequences and line wrapping.

Code-entry behavior:

• Observed code delimiter: #.
• Submission terminator: carriage return/Enter in the PTY; the synthetic pipe attempt used LF.
• Echo: input is masked as * characters; the synthetic code itself is not rendered by Claude.
• Prompt stream: the PTY’s terminal output stream (stdout/stderr are not independently observable once attached to one PTY).

Invalid-code result:

OAuth error: Request failed with status code 400
Press Enter to retry.

• The invalid code does not make the command exit; it remains at the retry UI.
• Controlled PTY termination: wrapper exit 124; direct child termination in the harness: SIGKILL (-9).

Deferred success-token assumption

No real login or token was captured in this phase. Implementation should provisionally expect an opaque setup token shaped like sk-ant-oat01-<opaque> on the interactive terminal output stream after successful authorization. Both the exact prefix/length/delimiters and whether a non-PTY capture classifies the success line as stdout or stderr remain explicit assumptions. Confirm them once in the final live end-to-end implementation test before locking parser assertions.

Smallest proof

claude --version; one pipe harness with a synthetic invalid code; and one PTY harness with bracketed-paste input showed the stream split, redacted URL structure, masked echo, HTTP 400 retry behavior, and controlled terminal exits. A literal scan of this document confirms it contains no authorization query values, browser code, or live token.

Re-characterization on Claude Code 2.1.226 (2026-08-13)

• Re-characterized: 2026-08-13
• Claude Code: 2.1.226
• Environment: real pseudo-terminal, headless, no browser. Prompt phase only; no login was completed and no token was minted.
• Safety: no real authorization URL, browser code, or token is recorded here.

A live run of claude setup-token on a real pseudo-terminal confirmed the prompt contract is unchanged in substance from 2.1.205:

• URL preamble line: Browser didn't open? Use the url below to sign in (c to copy).
• Authorization URL origin https://claude.com, path /cai/oauth/authorize, the same eight query keys (client_id, code, code_challenge, code_challenge_method, redirect_uri, response_type, scope, state), no fragment. The redirect_uri value host is https://platform.claude.com.
• Browser-code prompt line: Paste code here if prompted >.

The live run recorded two terminal-rendering behaviors that the earlier normalized capture hid. The parser now handles both:

1. Word spacing. The login UI lays out each word at an absolute column with a Cursor Horizontal Absolute (ESC[<n>G) sequence, so it emits no literal space between two words. A parser that removes the control sequence glues the words together. The parser now renders each horizontal-move sequence as one space.
2. Repeated URL. The UI emits one OSC 8 hyperlink per wrapped display row, so it repeats the full authorization URL on a few consecutive lines before the prompt. The parser now skips a repeated URL line and binds the prompt on the first non-blank line after the URL block; any other unrelated line still fails the bind.

The success anchors and the token shape were not re-run live, because a real login needs a subscription and an out-of-band browser. They stay as recorded in setup-token-success.md: the before-anchor line Your OAuth token (valid for 1 year):, the after-anchor line Store this token securely. You won't be able to see it again., and the token prefix sk-ant-oat01-. The success screen renders its anchor words with the same Cursor Horizontal Absolute spacing, so the same rendering fix applies to the token parser.

An executable characterization test drives this live run. See ../setup-token-characterization.test.ts; it is opt-in through RUN_CLAUDE_SETUP_TOKEN_CHARACTERIZATION=1.

Re-characterization on Claude Code 2.1.19 (2026-08-15)

• Re-characterized: 2026-08-15
• Claude Code: 2.1.19
• Environment: real Daytona sandbox, image daytonaio/sandbox:0.8.0, headless, no browser. Prompt phase only; no login was completed and no token was minted.
• Safety: no real authorization URL, browser code, or token is recorded here. Every query value below is a same-shape synthetic placeholder that passes the parser value validators.

The production sandbox image ships claude 2.1.19. A real Daytona smoke found that this version emits a different login contract than 2.1.205 and 2.1.226. The parser now accepts both contracts:

• Authorization URL for 2.1.19: origin https://claude.ai, path /oauth/authorize. The full pair is https://claude.ai/oauth/authorize.
• Authorization URL for 2.1.205 and 2.1.226: origin https://claude.com, path /cai/oauth/authorize. The full pair is https://claude.com/cai/oauth/authorize.
• Both versions carry the same eight query keys: client_id, code, code_challenge, code_challenge_method, redirect_uri, response_type, scope, state. No fragment.
• The redirect_uri value is the static callback https://platform.claude.com/oauth/code/callback. A real 2.1.19 capture confirmed this exact value, so the parser keeps the single pin.
• The code value is a short opaque token. A real 2.1.19 capture measured a four-character value, so the parser accepts a code value of one or more characters.
• Browser-code prompt line: Paste code here if prompted >.

Two rendering differences from 2.1.226:

1. No OSC 8 hyperlink. 2.1.19 prints the URL as plain text, not as an OSC 8 hyperlink.
2. Hard line wrap. 2.1.19 wraps the plain-text URL across several physical lines at the terminal width, with no space at the wrap. The parser joins the URL-character-only physical lines and validates only the final reassembled string.

Sanitized rendered form of the wrapped URL (placeholder values):

Browser didn't open? Use the url below to sign in (c to copy)
https://claude.ai/oauth/authorize?client_id=9d1c8f00-1a2b-3c4d-5e6f-708192a3b4c5&code=wZ9x&code_challenge=E9Melhoa2OwvFr
EMTJguCHaoeK1t8URWbuGJSstw-cM&code_challenge_method=S256&redirect_uri=https%3A%2F%2Fplatform.claude.com%2Foauth%2Fcode%2
Fcallback&response_type=code&scope=user%3Ainference&state=Xy7Kd2Pq9Rn4Vb8Lf1Mw6Zc3Hj0Tg5Us
Paste code here if prompted >