Custom setting values were JSON-escaped but emitted unquoted, so any
non-numeric value (e.g. "high") produced an invalid JSON payload and
failed the whole request; quoting the value manually could not work
either, since the escaper turns quotes into \". Emit RFC 8259 scalars
(number/true/false/null) bare and everything else as a quoted JSON
string.
Reserved payload keys (model, messages, stream) would duplicate the
fixed fields with parser-dependent precedence; reject them in
ai_set_provider_setting (surfaced as an error by /ai set custom) and
skip them at payload-build time for settings loaded from hand-edited
prefs.
provider->settings was mutated on the main thread while the request
thread iterates it when building the payload; guard both sides with a
new per-provider settings_lock.
Also refresh stale docs: ai_parse_response no longer mentions the
dropped Perplexity "text" path, the payload docstring says "messages"
instead of "input", and the /ai help example uses a realistic scalar
setting.
Add an AI client module that integrates with OpenAI-compatible API
providers (OpenAI, Perplexity, and custom endpoints) to provide
AI-assisted chat within CProof. Users can start sessions with /ai start,
send prompts, receive responses in a dedicated AI window, switch between
providers and models, and manage API keys — all with tab-completion.
Providers are configured via /ai set commands with per-provider API keys,
endpoints, default models, and custom settings. Two default providers
(openai, perplexity) are seeded on first use. Provider state persists in
[ai/<name>] sections of the preferences keyfile with automatic migration
from the previous flat-key format.
The /ai command integrates into the existing command system with 8
subcommands covering provider management, session lifecycle, model
fetching, and conversation clearing. Autocomplete uses the standard
flat prefix-matching chain for reliable tab-completion at every nesting
level. A new ProfAiWin window type is added to the window system.
Architecture:
Async design: HTTP requests run on a background thread (pthread) to avoid blocking the ncurses UI loop; results are displayed on the main thread via direct function calls
Thread safety: AIProvider and AISession use atomic ref-counting and mutex-protected session state; the request thread snapshots all session data before making the HTTP call
Window validation: wins_ai_exists() prevents use-after-free when the user closes the AI window during an in-flight HTTP request (~60s)
Privacy: store:false is sent with every request to prevent providers from persisting conversations or using them for training
Response size limit: 10MB cap with immediate curl abort via CURL_WRITEFUNC_ERROR to prevent OOM
JSON parsing uses unified helpers for both chat responses and error
envelopes with consistent escape decoding. The response parser tries
Perplexity /v1/responses "text" field first, then falls back to OpenAI
"content". Error parsing extracts provider error.message from the
standard envelope format. Model parsing handles multiple API response
formats (OpenAI list, Perplexity, array) including edge cases.
Tests include 470+ lines of unit tests covering provider management,
session lifecycle, JSON parsing (multiple formats), autocomplete cycling,
and error handling, plus functional tests for /ai command dispatch.
A stub_ai.c module isolates unit tests from UI dependencies.
